From 1661f2e21c8bbf922dcb76faf2126a33ffe4cddb Mon Sep 17 00:00:00 2001 From: Vlastimil Babka Date: Wed, 4 Jan 2017 11:19:31 +0100 Subject: [PATCH 01/49] floppy: replace wrong kmalloc(GFP_USER) with GFP_KERNEL The raw_cmd_copyin() function does a kmalloc() with GFP_USER, although the allocated structure is obviously not mapped to userspace, just copied from/to. In this case GFP_KERNEL is more appropriate, so let's use it, although in the current implementation this does not manifest as any error. Reported-by: Matthew Wilcox Signed-off-by: Vlastimil Babka Signed-off-by: Jiri Kosina --- drivers/block/floppy.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c index a391a3cfb3fe..184887af4b9f 100644 --- a/drivers/block/floppy.c +++ b/drivers/block/floppy.c @@ -3119,7 +3119,7 @@ static int raw_cmd_copyin(int cmd, void __user *param, *rcmd = NULL; loop: - ptr = kmalloc(sizeof(struct floppy_raw_cmd), GFP_USER); + ptr = kmalloc(sizeof(struct floppy_raw_cmd), GFP_KERNEL); if (!ptr) return -ENOMEM; *rcmd = ptr; From 729204ef49ec00b788ce23deb9eb922a5769f55d Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Sat, 17 Dec 2016 18:49:09 +0800 Subject: [PATCH 02/49] block: relax check on sg gap If the last bvec of the 1st bio and the 1st bvec of the next bio are physically contigious, and the latter can be merged to last segment of the 1st bio, we should think they don't violate sg gap(or virt boundary) limit. Both Vitaly and Dexuan reported lots of unmergeable small bios are observed when running mkfs on Hyper-V virtual storage, and performance becomes quite low. This patch fixes that performance issue. The same issue should exist on NVMe, since it sets virt boundary too. Reported-by: Vitaly Kuznetsov Reported-by: Dexuan Cui Tested-by: Dexuan Cui Cc: Keith Busch Signed-off-by: Ming Lei Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-) diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 83695641bd5e..b20da8dfa7ec 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1607,6 +1607,25 @@ static inline bool bvec_gap_to_prev(struct request_queue *q, return __bvec_gap_to_prev(q, bprv, offset); } +/* + * Check if the two bvecs from two bios can be merged to one segment. + * If yes, no need to check gap between the two bios since the 1st bio + * and the 1st bvec in the 2nd bio can be handled in one segment. + */ +static inline bool bios_segs_mergeable(struct request_queue *q, + struct bio *prev, struct bio_vec *prev_last_bv, + struct bio_vec *next_first_bv) +{ + if (!BIOVEC_PHYS_MERGEABLE(prev_last_bv, next_first_bv)) + return false; + if (!BIOVEC_SEG_BOUNDARY(q, prev_last_bv, next_first_bv)) + return false; + if (prev->bi_seg_back_size + next_first_bv->bv_len > + queue_max_segment_size(q)) + return false; + return true; +} + static inline bool bio_will_gap(struct request_queue *q, struct bio *prev, struct bio *next) { @@ -1616,7 +1635,8 @@ static inline bool bio_will_gap(struct request_queue *q, struct bio *prev, bio_get_last_bvec(prev, &pb); bio_get_first_bvec(next, &nb); - return __bvec_gap_to_prev(q, &pb, nb.bv_offset); + if (!bios_segs_mergeable(q, prev, &pb, &nb)) + return __bvec_gap_to_prev(q, &pb, nb.bv_offset); } return false; From f8a5b12247fe18f7fed801ad262a7ab190e1f848 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 13 Dec 2016 09:24:51 -0700 Subject: [PATCH 03/49] blk-mq: make mq_ops a const pointer We never change it, make that clear. Signed-off-by: Jens Axboe Reviewed-by: Bart Van Assche --- block/blk-mq.c | 2 +- include/linux/blk-mq.h | 2 +- include/linux/blkdev.h | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index a8e67a155d04..79e1cb0f7b15 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -639,7 +639,7 @@ struct blk_mq_timeout_data { void blk_mq_rq_timed_out(struct request *req, bool reserved) { - struct blk_mq_ops *ops = req->q->mq_ops; + const struct blk_mq_ops *ops = req->q->mq_ops; enum blk_eh_timer_return ret = BLK_EH_RESET_TIMER; /* diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 4a2ab5d99ff7..afc81d77e471 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -60,7 +60,7 @@ struct blk_mq_hw_ctx { struct blk_mq_tag_set { unsigned int *mq_map; - struct blk_mq_ops *ops; + const struct blk_mq_ops *ops; unsigned int nr_hw_queues; unsigned int queue_depth; /* max hw supported */ unsigned int reserved_tags; diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index b20da8dfa7ec..2e99d659b0f1 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -407,7 +407,7 @@ struct request_queue { dma_drain_needed_fn *dma_drain_needed; lld_busy_fn *lld_busy_fn; - struct blk_mq_ops *mq_ops; + const struct blk_mq_ops *mq_ops; unsigned int *mq_map; From 1e668f4e7921e8c82838cf5f95ff4a2d5c852efc Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Wed, 11 Jan 2017 15:41:40 -0500 Subject: [PATCH 04/49] MAINTAINERS: Update maintainer entry for NBD The old maintainers email is bouncing and I've rewritten most of this driver in the recent months. Also add linux-block to the mailinglist and remove the old tree, I will send patches through the linux-block tree. Thanks, Signed-off-by: Josef Bacik Signed-off-by: Jens Axboe --- MAINTAINERS | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/MAINTAINERS b/MAINTAINERS index 5f0420a0da5b..f481713fe44c 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -8599,10 +8599,10 @@ S: Maintained F: drivers/net/ethernet/netronome/ NETWORK BLOCK DEVICE (NBD) -M: Markus Pargmann +M: Josef Bacik S: Maintained +L: linux-block@vger.kernel.org L: nbd-general@lists.sourceforge.net -T: git git://git.pengutronix.de/git/mpa/linux-nbd.git F: Documentation/blockdev/nbd.txt F: drivers/block/nbd.c F: include/uapi/linux/nbd.h From c5082b70adfe8e1ea1cf4a8eff92c9f260e364d2 Mon Sep 17 00:00:00 2001 From: Alden Tondettar Date: Sun, 15 Jan 2017 15:31:56 -0700 Subject: [PATCH 05/49] partitions/efi: Fix integer overflow in GPT size calculation If a GUID Partition Table claims to have more than 2**25 entries, the calculation of the partition table size in alloc_read_gpt_entries() will overflow a 32-bit integer and not enough space will be allocated for the table. Nothing seems to get written out of bounds, but later efi_partition() will read up to 32768 bytes from a 128 byte buffer, possibly OOPSing or exposing information to /proc/partitions and uevents. The problem exists on both 64-bit and 32-bit platforms. Fix the overflow and also print a meaningful debug message if the table size is too large. Signed-off-by: Alden Tondettar Acked-by: Ard Biesheuvel Signed-off-by: Jens Axboe --- block/partitions/efi.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/block/partitions/efi.c b/block/partitions/efi.c index bcd86e5cd546..39f70d968754 100644 --- a/block/partitions/efi.c +++ b/block/partitions/efi.c @@ -293,7 +293,7 @@ static gpt_entry *alloc_read_gpt_entries(struct parsed_partitions *state, if (!gpt) return NULL; - count = le32_to_cpu(gpt->num_partition_entries) * + count = (size_t)le32_to_cpu(gpt->num_partition_entries) * le32_to_cpu(gpt->sizeof_partition_entry); if (!count) return NULL; @@ -352,7 +352,7 @@ static int is_gpt_valid(struct parsed_partitions *state, u64 lba, gpt_header **gpt, gpt_entry **ptes) { u32 crc, origcrc; - u64 lastlba; + u64 lastlba, pt_size; if (!ptes) return 0; @@ -434,13 +434,20 @@ static int is_gpt_valid(struct parsed_partitions *state, u64 lba, goto fail; } + /* Sanity check partition table size */ + pt_size = (u64)le32_to_cpu((*gpt)->num_partition_entries) * + le32_to_cpu((*gpt)->sizeof_partition_entry); + if (pt_size > KMALLOC_MAX_SIZE) { + pr_debug("GUID Partition Table is too large: %llu > %lu bytes\n", + (unsigned long long)pt_size, KMALLOC_MAX_SIZE); + goto fail; + } + if (!(*ptes = alloc_read_gpt_entries(state, *gpt))) goto fail; /* Check the GUID Partition Entry Array CRC */ - crc = efi_crc32((const unsigned char *) (*ptes), - le32_to_cpu((*gpt)->num_partition_entries) * - le32_to_cpu((*gpt)->sizeof_partition_entry)); + crc = efi_crc32((const unsigned char *) (*ptes), pt_size); if (crc != le32_to_cpu((*gpt)->partition_entry_array_crc32)) { pr_debug("GUID Partition Entry Array CRC check failed.\n"); From c51ca6cf545bc51ad38bd50816bde37c647d608d Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Sat, 10 Dec 2016 15:13:59 -0700 Subject: [PATCH 06/49] block: move existing elevator ops to union Prep patch for adding MQ ops as well, since doing anon unions with named initializers doesn't work on older compilers. Signed-off-by: Jens Axboe Reviewed-by: Johannes Thumshirn Reviewed-by: Bart Van Assche Reviewed-by: Omar Sandoval --- block/blk-ioc.c | 8 +++--- block/blk-merge.c | 4 +-- block/blk.h | 10 +++---- block/cfq-iosched.c | 2 +- block/deadline-iosched.c | 2 +- block/elevator.c | 60 ++++++++++++++++++++-------------------- block/noop-iosched.c | 2 +- include/linux/elevator.h | 4 ++- 8 files changed, 47 insertions(+), 45 deletions(-) diff --git a/block/blk-ioc.c b/block/blk-ioc.c index 381cb50a673c..ab372092a57d 100644 --- a/block/blk-ioc.c +++ b/block/blk-ioc.c @@ -43,8 +43,8 @@ static void ioc_exit_icq(struct io_cq *icq) if (icq->flags & ICQ_EXITED) return; - if (et->ops.elevator_exit_icq_fn) - et->ops.elevator_exit_icq_fn(icq); + if (et->ops.sq.elevator_exit_icq_fn) + et->ops.sq.elevator_exit_icq_fn(icq); icq->flags |= ICQ_EXITED; } @@ -383,8 +383,8 @@ struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q, if (likely(!radix_tree_insert(&ioc->icq_tree, q->id, icq))) { hlist_add_head(&icq->ioc_node, &ioc->icq_list); list_add(&icq->q_node, &q->icq_list); - if (et->ops.elevator_init_icq_fn) - et->ops.elevator_init_icq_fn(icq); + if (et->ops.sq.elevator_init_icq_fn) + et->ops.sq.elevator_init_icq_fn(icq); } else { kmem_cache_free(et->icq_cache, icq); icq = ioc_lookup_icq(ioc, q); diff --git a/block/blk-merge.c b/block/blk-merge.c index 182398cb1524..480570b691dc 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -763,8 +763,8 @@ int blk_attempt_req_merge(struct request_queue *q, struct request *rq, { struct elevator_queue *e = q->elevator; - if (e->type->ops.elevator_allow_rq_merge_fn) - if (!e->type->ops.elevator_allow_rq_merge_fn(q, rq, next)) + if (e->type->ops.sq.elevator_allow_rq_merge_fn) + if (!e->type->ops.sq.elevator_allow_rq_merge_fn(q, rq, next)) return 0; return attempt_merge(q, rq, next); diff --git a/block/blk.h b/block/blk.h index 041185e5f129..f46c0ac8ae3d 100644 --- a/block/blk.h +++ b/block/blk.h @@ -167,7 +167,7 @@ static inline struct request *__elv_next_request(struct request_queue *q) return NULL; } if (unlikely(blk_queue_bypass(q)) || - !q->elevator->type->ops.elevator_dispatch_fn(q, 0)) + !q->elevator->type->ops.sq.elevator_dispatch_fn(q, 0)) return NULL; } } @@ -176,16 +176,16 @@ static inline void elv_activate_rq(struct request_queue *q, struct request *rq) { struct elevator_queue *e = q->elevator; - if (e->type->ops.elevator_activate_req_fn) - e->type->ops.elevator_activate_req_fn(q, rq); + if (e->type->ops.sq.elevator_activate_req_fn) + e->type->ops.sq.elevator_activate_req_fn(q, rq); } static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq) { struct elevator_queue *e = q->elevator; - if (e->type->ops.elevator_deactivate_req_fn) - e->type->ops.elevator_deactivate_req_fn(q, rq); + if (e->type->ops.sq.elevator_deactivate_req_fn) + e->type->ops.sq.elevator_deactivate_req_fn(q, rq); } #ifdef CONFIG_FAIL_IO_TIMEOUT diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index c73a6fcaeb9d..37aeb20fa454 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -4837,7 +4837,7 @@ static struct elv_fs_entry cfq_attrs[] = { }; static struct elevator_type iosched_cfq = { - .ops = { + .ops.sq = { .elevator_merge_fn = cfq_merge, .elevator_merged_fn = cfq_merged_request, .elevator_merge_req_fn = cfq_merged_requests, diff --git a/block/deadline-iosched.c b/block/deadline-iosched.c index 55e0bb6d7da7..05fc0ea25a98 100644 --- a/block/deadline-iosched.c +++ b/block/deadline-iosched.c @@ -439,7 +439,7 @@ static struct elv_fs_entry deadline_attrs[] = { }; static struct elevator_type iosched_deadline = { - .ops = { + .ops.sq = { .elevator_merge_fn = deadline_merge, .elevator_merged_fn = deadline_merged_request, .elevator_merge_req_fn = deadline_merged_requests, diff --git a/block/elevator.c b/block/elevator.c index 40f0c04e5ad3..022a26830297 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -58,8 +58,8 @@ static int elv_iosched_allow_bio_merge(struct request *rq, struct bio *bio) struct request_queue *q = rq->q; struct elevator_queue *e = q->elevator; - if (e->type->ops.elevator_allow_bio_merge_fn) - return e->type->ops.elevator_allow_bio_merge_fn(q, rq, bio); + if (e->type->ops.sq.elevator_allow_bio_merge_fn) + return e->type->ops.sq.elevator_allow_bio_merge_fn(q, rq, bio); return 1; } @@ -224,7 +224,7 @@ int elevator_init(struct request_queue *q, char *name) } } - err = e->ops.elevator_init_fn(q, e); + err = e->ops.sq.elevator_init_fn(q, e); if (err) elevator_put(e); return err; @@ -234,8 +234,8 @@ EXPORT_SYMBOL(elevator_init); void elevator_exit(struct elevator_queue *e) { mutex_lock(&e->sysfs_lock); - if (e->type->ops.elevator_exit_fn) - e->type->ops.elevator_exit_fn(e); + if (e->type->ops.sq.elevator_exit_fn) + e->type->ops.sq.elevator_exit_fn(e); mutex_unlock(&e->sysfs_lock); kobject_put(&e->kobj); @@ -443,8 +443,8 @@ int elv_merge(struct request_queue *q, struct request **req, struct bio *bio) return ELEVATOR_BACK_MERGE; } - if (e->type->ops.elevator_merge_fn) - return e->type->ops.elevator_merge_fn(q, req, bio); + if (e->type->ops.sq.elevator_merge_fn) + return e->type->ops.sq.elevator_merge_fn(q, req, bio); return ELEVATOR_NO_MERGE; } @@ -495,8 +495,8 @@ void elv_merged_request(struct request_queue *q, struct request *rq, int type) { struct elevator_queue *e = q->elevator; - if (e->type->ops.elevator_merged_fn) - e->type->ops.elevator_merged_fn(q, rq, type); + if (e->type->ops.sq.elevator_merged_fn) + e->type->ops.sq.elevator_merged_fn(q, rq, type); if (type == ELEVATOR_BACK_MERGE) elv_rqhash_reposition(q, rq); @@ -510,8 +510,8 @@ void elv_merge_requests(struct request_queue *q, struct request *rq, struct elevator_queue *e = q->elevator; const int next_sorted = next->rq_flags & RQF_SORTED; - if (next_sorted && e->type->ops.elevator_merge_req_fn) - e->type->ops.elevator_merge_req_fn(q, rq, next); + if (next_sorted && e->type->ops.sq.elevator_merge_req_fn) + e->type->ops.sq.elevator_merge_req_fn(q, rq, next); elv_rqhash_reposition(q, rq); @@ -528,8 +528,8 @@ void elv_bio_merged(struct request_queue *q, struct request *rq, { struct elevator_queue *e = q->elevator; - if (e->type->ops.elevator_bio_merged_fn) - e->type->ops.elevator_bio_merged_fn(q, rq, bio); + if (e->type->ops.sq.elevator_bio_merged_fn) + e->type->ops.sq.elevator_bio_merged_fn(q, rq, bio); } #ifdef CONFIG_PM @@ -578,7 +578,7 @@ void elv_drain_elevator(struct request_queue *q) lockdep_assert_held(q->queue_lock); - while (q->elevator->type->ops.elevator_dispatch_fn(q, 1)) + while (q->elevator->type->ops.sq.elevator_dispatch_fn(q, 1)) ; if (q->nr_sorted && printed++ < 10) { printk(KERN_ERR "%s: forced dispatching is broken " @@ -653,7 +653,7 @@ void __elv_add_request(struct request_queue *q, struct request *rq, int where) * rq cannot be accessed after calling * elevator_add_req_fn. */ - q->elevator->type->ops.elevator_add_req_fn(q, rq); + q->elevator->type->ops.sq.elevator_add_req_fn(q, rq); break; case ELEVATOR_INSERT_FLUSH: @@ -682,8 +682,8 @@ struct request *elv_latter_request(struct request_queue *q, struct request *rq) { struct elevator_queue *e = q->elevator; - if (e->type->ops.elevator_latter_req_fn) - return e->type->ops.elevator_latter_req_fn(q, rq); + if (e->type->ops.sq.elevator_latter_req_fn) + return e->type->ops.sq.elevator_latter_req_fn(q, rq); return NULL; } @@ -691,8 +691,8 @@ struct request *elv_former_request(struct request_queue *q, struct request *rq) { struct elevator_queue *e = q->elevator; - if (e->type->ops.elevator_former_req_fn) - return e->type->ops.elevator_former_req_fn(q, rq); + if (e->type->ops.sq.elevator_former_req_fn) + return e->type->ops.sq.elevator_former_req_fn(q, rq); return NULL; } @@ -701,8 +701,8 @@ int elv_set_request(struct request_queue *q, struct request *rq, { struct elevator_queue *e = q->elevator; - if (e->type->ops.elevator_set_req_fn) - return e->type->ops.elevator_set_req_fn(q, rq, bio, gfp_mask); + if (e->type->ops.sq.elevator_set_req_fn) + return e->type->ops.sq.elevator_set_req_fn(q, rq, bio, gfp_mask); return 0; } @@ -710,16 +710,16 @@ void elv_put_request(struct request_queue *q, struct request *rq) { struct elevator_queue *e = q->elevator; - if (e->type->ops.elevator_put_req_fn) - e->type->ops.elevator_put_req_fn(rq); + if (e->type->ops.sq.elevator_put_req_fn) + e->type->ops.sq.elevator_put_req_fn(rq); } int elv_may_queue(struct request_queue *q, unsigned int op) { struct elevator_queue *e = q->elevator; - if (e->type->ops.elevator_may_queue_fn) - return e->type->ops.elevator_may_queue_fn(q, op); + if (e->type->ops.sq.elevator_may_queue_fn) + return e->type->ops.sq.elevator_may_queue_fn(q, op); return ELV_MQUEUE_MAY; } @@ -734,8 +734,8 @@ void elv_completed_request(struct request_queue *q, struct request *rq) if (blk_account_rq(rq)) { q->in_flight[rq_is_sync(rq)]--; if ((rq->rq_flags & RQF_SORTED) && - e->type->ops.elevator_completed_req_fn) - e->type->ops.elevator_completed_req_fn(q, rq); + e->type->ops.sq.elevator_completed_req_fn) + e->type->ops.sq.elevator_completed_req_fn(q, rq); } } @@ -803,8 +803,8 @@ int elv_register_queue(struct request_queue *q) } kobject_uevent(&e->kobj, KOBJ_ADD); e->registered = 1; - if (e->type->ops.elevator_registered_fn) - e->type->ops.elevator_registered_fn(q); + if (e->type->ops.sq.elevator_registered_fn) + e->type->ops.sq.elevator_registered_fn(q); } return error; } @@ -912,7 +912,7 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e) spin_unlock_irq(q->queue_lock); /* allocate, init and register new elevator */ - err = new_e->ops.elevator_init_fn(q, new_e); + err = new_e->ops.sq.elevator_init_fn(q, new_e); if (err) goto fail_init; diff --git a/block/noop-iosched.c b/block/noop-iosched.c index a163c487cf38..2d1b15d89b45 100644 --- a/block/noop-iosched.c +++ b/block/noop-iosched.c @@ -92,7 +92,7 @@ static void noop_exit_queue(struct elevator_queue *e) } static struct elevator_type elevator_noop = { - .ops = { + .ops.sq = { .elevator_merge_req_fn = noop_merged_requests, .elevator_dispatch_fn = noop_dispatch, .elevator_add_req_fn = noop_add_request, diff --git a/include/linux/elevator.h b/include/linux/elevator.h index b276e9ef0e0b..2a9e966eed03 100644 --- a/include/linux/elevator.h +++ b/include/linux/elevator.h @@ -94,7 +94,9 @@ struct elevator_type struct kmem_cache *icq_cache; /* fields provided by elevator implementation */ - struct elevator_ops ops; + union { + struct elevator_ops sq; + } ops; size_t icq_size; /* see iocontext.h */ size_t icq_align; /* ditto */ struct elv_fs_entry *elevator_attrs; From c23ecb426084a98418ee29124c139e37c274ad04 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 14 Dec 2016 14:23:43 -0700 Subject: [PATCH 07/49] block: move rq_ioc() to blk.h We want to use it outside of blk-core.c. Signed-off-by: Jens Axboe Reviewed-by: Johannes Thumshirn Reviewed-by: Bart Van Assche Reviewed-by: Christoph Hellwig Reviewed-by: Omar Sandoval --- block/blk-core.c | 16 ---------------- block/blk.h | 16 ++++++++++++++++ 2 files changed, 16 insertions(+), 16 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 61ba08c58b64..92baea07acbc 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1039,22 +1039,6 @@ static bool blk_rq_should_init_elevator(struct bio *bio) return true; } -/** - * rq_ioc - determine io_context for request allocation - * @bio: request being allocated is for this bio (can be %NULL) - * - * Determine io_context to use for request allocation for @bio. May return - * %NULL if %current->io_context doesn't exist. - */ -static struct io_context *rq_ioc(struct bio *bio) -{ -#ifdef CONFIG_BLK_CGROUP - if (bio && bio->bi_ioc) - return bio->bi_ioc; -#endif - return current->io_context; -} - /** * __get_request - get a free request * @rl: request list to allocate from diff --git a/block/blk.h b/block/blk.h index f46c0ac8ae3d..9a716b5925a4 100644 --- a/block/blk.h +++ b/block/blk.h @@ -263,6 +263,22 @@ void ioc_clear_queue(struct request_queue *q); int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node); +/** + * rq_ioc - determine io_context for request allocation + * @bio: request being allocated is for this bio (can be %NULL) + * + * Determine io_context to use for request allocation for @bio. May return + * %NULL if %current->io_context doesn't exist. + */ +static inline struct io_context *rq_ioc(struct bio *bio) +{ +#ifdef CONFIG_BLK_CGROUP + if (bio && bio->bi_ioc) + return bio->bi_ioc; +#endif + return current->io_context; +} + /** * create_io_context - try to create task->io_context * @gfp_mask: allocation mask From 16a3c2a70cad5ccdc2dc0a4544bff82554807493 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 15 Dec 2016 14:27:46 -0700 Subject: [PATCH 08/49] blk-mq: un-export blk_mq_free_hctx_request() It's only used in blk-mq, kill it from the main exported header and kill the symbol export as well. Signed-off-by: Jens Axboe Reviewed-by: Johannes Thumshirn Reviewed-by: Bart Van Assche Reviewed-by: Christoph Hellwig Reviewed-by: Omar Sandoval --- block/blk-mq.c | 5 ++--- include/linux/blk-mq.h | 1 - 2 files changed, 2 insertions(+), 4 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 79e1cb0f7b15..f49f6325b332 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -337,15 +337,14 @@ static void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx, blk_queue_exit(q); } -void blk_mq_free_hctx_request(struct blk_mq_hw_ctx *hctx, struct request *rq) +static void blk_mq_free_hctx_request(struct blk_mq_hw_ctx *hctx, + struct request *rq) { struct blk_mq_ctx *ctx = rq->mq_ctx; ctx->rq_completed[rq_is_sync(rq)]++; __blk_mq_free_request(hctx, ctx, rq); - } -EXPORT_SYMBOL_GPL(blk_mq_free_hctx_request); void blk_mq_free_request(struct request *rq) { diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index afc81d77e471..2686f9e7302a 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -181,7 +181,6 @@ void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule); void blk_mq_insert_request(struct request *, bool, bool, bool); void blk_mq_free_request(struct request *rq); -void blk_mq_free_hctx_request(struct blk_mq_hw_ctx *, struct request *rq); bool blk_mq_can_queue(struct blk_mq_hw_ctx *); enum { From 2c3ad667902ef6f4b60ef0a3c6f7d8c2b007769a Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 14 Dec 2016 14:34:47 -0700 Subject: [PATCH 09/49] blk-mq: export some helpers we need to the scheduling framework Signed-off-by: Jens Axboe Reviewed-by: Johannes Thumshirn Reviewed-by: Omar Sandoval --- block/blk-mq.c | 39 +++++++++++++++++++++------------------ block/blk-mq.h | 25 +++++++++++++++++++++++++ 2 files changed, 46 insertions(+), 18 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index f49f6325b332..9fc521755e22 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -167,8 +167,8 @@ bool blk_mq_can_queue(struct blk_mq_hw_ctx *hctx) } EXPORT_SYMBOL(blk_mq_can_queue); -static void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx, - struct request *rq, unsigned int op) +void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx, + struct request *rq, unsigned int op) { INIT_LIST_HEAD(&rq->queuelist); /* csd/requeue_work/fifo_time is initialized before use */ @@ -213,9 +213,10 @@ static void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx, ctx->rq_dispatched[op_is_sync(op)]++; } +EXPORT_SYMBOL_GPL(blk_mq_rq_ctx_init); -static struct request * -__blk_mq_alloc_request(struct blk_mq_alloc_data *data, unsigned int op) +struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data, + unsigned int op) { struct request *rq; unsigned int tag; @@ -236,6 +237,7 @@ __blk_mq_alloc_request(struct blk_mq_alloc_data *data, unsigned int op) return NULL; } +EXPORT_SYMBOL_GPL(__blk_mq_alloc_request); struct request *blk_mq_alloc_request(struct request_queue *q, int rw, unsigned int flags) @@ -319,8 +321,8 @@ out_queue_exit: } EXPORT_SYMBOL_GPL(blk_mq_alloc_request_hctx); -static void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx, - struct blk_mq_ctx *ctx, struct request *rq) +void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, + struct request *rq) { const int tag = rq->tag; struct request_queue *q = rq->q; @@ -802,7 +804,7 @@ static bool flush_busy_ctx(struct sbitmap *sb, unsigned int bitnr, void *data) * Process software queues that have been marked busy, splicing them * to the for-dispatch */ -static void flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list) +void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list) { struct flush_busy_ctx_data data = { .hctx = hctx, @@ -811,6 +813,7 @@ static void flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list) sbitmap_for_each_set(&hctx->ctx_map, flush_busy_ctx, &data); } +EXPORT_SYMBOL_GPL(blk_mq_flush_busy_ctxs); static inline unsigned int queued_to_index(unsigned int queued) { @@ -921,7 +924,7 @@ static void blk_mq_process_rq_list(struct blk_mq_hw_ctx *hctx) /* * Touch any software queue that has pending entries. */ - flush_busy_ctxs(hctx, &rq_list); + blk_mq_flush_busy_ctxs(hctx, &rq_list); /* * If we have previous entries on our dispatch list, grab them @@ -1135,8 +1138,8 @@ static inline void __blk_mq_insert_req_list(struct blk_mq_hw_ctx *hctx, list_add_tail(&rq->queuelist, &ctx->rq_list); } -static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, - struct request *rq, bool at_head) +void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, + bool at_head) { struct blk_mq_ctx *ctx = rq->mq_ctx; @@ -1550,8 +1553,8 @@ run_queue: return cookie; } -static void blk_mq_free_rq_map(struct blk_mq_tag_set *set, - struct blk_mq_tags *tags, unsigned int hctx_idx) +void blk_mq_free_rq_map(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, + unsigned int hctx_idx) { struct page *page; @@ -1588,8 +1591,8 @@ static size_t order_to_size(unsigned int order) return (size_t)PAGE_SIZE << order; } -static struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set, - unsigned int hctx_idx) +struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set, + unsigned int hctx_idx) { struct blk_mq_tags *tags; unsigned int i, j, entries_per_page, max_order = 4; @@ -2279,10 +2282,10 @@ static int blk_mq_queue_reinit_dead(unsigned int cpu) * Now CPU1 is just onlined and a request is inserted into ctx1->rq_list * and set bit0 in pending bitmap as ctx1->index_hw is still zero. * - * And then while running hw queue, flush_busy_ctxs() finds bit0 is set in - * pending bitmap and tries to retrieve requests in hctx->ctxs[0]->rq_list. - * But htx->ctxs[0] is a pointer to ctx0, so the request in ctx1->rq_list - * is ignored. + * And then while running hw queue, blk_mq_flush_busy_ctxs() finds bit0 is set + * in pending bitmap and tries to retrieve requests in hctx->ctxs[0]->rq_list. + * But htx->ctxs[0] is a pointer to ctx0, so the request in ctx1->rq_list is + * ignored. */ static int blk_mq_queue_reinit_prepare(unsigned int cpu) { diff --git a/block/blk-mq.h b/block/blk-mq.h index 63e9116cddbd..e59f5ca520a2 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -32,6 +32,21 @@ void blk_mq_free_queue(struct request_queue *q); int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr); void blk_mq_wake_waiters(struct request_queue *q); bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *, struct list_head *); +void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list); + +/* + * Internal helpers for allocating/freeing the request map + */ +void blk_mq_free_rq_map(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, + unsigned int hctx_idx); +struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set, + unsigned int hctx_idx); + +/* + * Internal helpers for request insertion into sw queues + */ +void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, + bool at_head); /* * CPU hotplug helpers @@ -103,6 +118,16 @@ static inline void blk_mq_set_alloc_data(struct blk_mq_alloc_data *data, data->hctx = hctx; } +/* + * Internal helpers for request allocation/init/free + */ +void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx, + struct request *rq, unsigned int op); +void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, + struct request *rq); +struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data, + unsigned int op); + static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx) { return test_bit(BLK_MQ_S_STOPPED, &hctx->state); From 4941115bef2bc891aa00a2f0edeaf06dc982325a Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Fri, 13 Jan 2017 08:09:05 -0700 Subject: [PATCH 10/49] blk-mq-tag: cleanup the normal/reserved tag allocation This is in preparation for having another tag set available. Cleanup the parameters, and allow passing in of tags for blk_mq_put_tag(). Signed-off-by: Jens Axboe [hch: even more cleanups] Signed-off-by: Christoph Hellwig Reviewed-by: Omar Sandoval --- block/blk-mq-tag.c | 96 ++++++++++++++++++---------------------------- block/blk-mq-tag.h | 4 +- block/blk-mq.c | 2 +- block/blk-mq.h | 5 +++ 4 files changed, 45 insertions(+), 62 deletions(-) diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index dcf5ce3ba4bf..ced752716878 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -90,32 +90,46 @@ static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx, return atomic_read(&hctx->nr_active) < depth; } -static int __bt_get(struct blk_mq_hw_ctx *hctx, struct sbitmap_queue *bt) +static int __blk_mq_get_tag(struct blk_mq_hw_ctx *hctx, struct sbitmap_queue *bt) { if (!hctx_may_queue(hctx, bt)) return -1; return __sbitmap_queue_get(bt); } -static int bt_get(struct blk_mq_alloc_data *data, struct sbitmap_queue *bt, - struct blk_mq_hw_ctx *hctx, struct blk_mq_tags *tags) +unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data) { + struct blk_mq_tags *tags = blk_mq_tags_from_data(data); + struct sbitmap_queue *bt; struct sbq_wait_state *ws; DEFINE_WAIT(wait); + unsigned int tag_offset; int tag; - tag = __bt_get(hctx, bt); + if (data->flags & BLK_MQ_REQ_RESERVED) { + if (unlikely(!tags->nr_reserved_tags)) { + WARN_ON_ONCE(1); + return BLK_MQ_TAG_FAIL; + } + bt = &tags->breserved_tags; + tag_offset = 0; + } else { + bt = &tags->bitmap_tags; + tag_offset = tags->nr_reserved_tags; + } + + tag = __blk_mq_get_tag(data->hctx, bt); if (tag != -1) - return tag; + goto found_tag; if (data->flags & BLK_MQ_REQ_NOWAIT) - return -1; + return BLK_MQ_TAG_FAIL; - ws = bt_wait_ptr(bt, hctx); + ws = bt_wait_ptr(bt, data->hctx); do { prepare_to_wait(&ws->wait, &wait, TASK_UNINTERRUPTIBLE); - tag = __bt_get(hctx, bt); + tag = __blk_mq_get_tag(data->hctx, bt); if (tag != -1) break; @@ -125,14 +139,14 @@ static int bt_get(struct blk_mq_alloc_data *data, struct sbitmap_queue *bt, * some to complete. Note that hctx can be NULL here for * reserved tag allocation. */ - if (hctx) - blk_mq_run_hw_queue(hctx, false); + if (data->hctx) + blk_mq_run_hw_queue(data->hctx, false); /* * Retry tag allocation after running the hardware queue, * as running the queue may also have found completions. */ - tag = __bt_get(hctx, bt); + tag = __blk_mq_get_tag(data->hctx, bt); if (tag != -1) break; @@ -142,61 +156,25 @@ static int bt_get(struct blk_mq_alloc_data *data, struct sbitmap_queue *bt, data->ctx = blk_mq_get_ctx(data->q); data->hctx = blk_mq_map_queue(data->q, data->ctx->cpu); - if (data->flags & BLK_MQ_REQ_RESERVED) { - bt = &data->hctx->tags->breserved_tags; - } else { - hctx = data->hctx; - bt = &hctx->tags->bitmap_tags; - } + tags = blk_mq_tags_from_data(data); + if (data->flags & BLK_MQ_REQ_RESERVED) + bt = &tags->breserved_tags; + else + bt = &tags->bitmap_tags; + finish_wait(&ws->wait, &wait); - ws = bt_wait_ptr(bt, hctx); + ws = bt_wait_ptr(bt, data->hctx); } while (1); finish_wait(&ws->wait, &wait); - return tag; + +found_tag: + return tag + tag_offset; } -static unsigned int __blk_mq_get_tag(struct blk_mq_alloc_data *data) +void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, struct blk_mq_tags *tags, + struct blk_mq_ctx *ctx, unsigned int tag) { - int tag; - - tag = bt_get(data, &data->hctx->tags->bitmap_tags, data->hctx, - data->hctx->tags); - if (tag >= 0) - return tag + data->hctx->tags->nr_reserved_tags; - - return BLK_MQ_TAG_FAIL; -} - -static unsigned int __blk_mq_get_reserved_tag(struct blk_mq_alloc_data *data) -{ - int tag; - - if (unlikely(!data->hctx->tags->nr_reserved_tags)) { - WARN_ON_ONCE(1); - return BLK_MQ_TAG_FAIL; - } - - tag = bt_get(data, &data->hctx->tags->breserved_tags, NULL, - data->hctx->tags); - if (tag < 0) - return BLK_MQ_TAG_FAIL; - - return tag; -} - -unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data) -{ - if (data->flags & BLK_MQ_REQ_RESERVED) - return __blk_mq_get_reserved_tag(data); - return __blk_mq_get_tag(data); -} - -void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, - unsigned int tag) -{ - struct blk_mq_tags *tags = hctx->tags; - if (tag >= tags->nr_reserved_tags) { const int real_tag = tag - tags->nr_reserved_tags; diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h index d1662734dc53..923602dd3bfb 100644 --- a/block/blk-mq-tag.h +++ b/block/blk-mq-tag.h @@ -24,8 +24,8 @@ extern struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags, unsigned int r extern void blk_mq_free_tags(struct blk_mq_tags *tags); extern unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data); -extern void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, - unsigned int tag); +extern void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, struct blk_mq_tags *tags, + struct blk_mq_ctx *ctx, unsigned int tag); extern bool blk_mq_has_free_tags(struct blk_mq_tags *tags); extern ssize_t blk_mq_tag_sysfs_show(struct blk_mq_tags *tags, char *page); extern int blk_mq_tag_update_depth(struct blk_mq_tags *tags, unsigned int depth); diff --git a/block/blk-mq.c b/block/blk-mq.c index 9fc521755e22..6fab8e9c724f 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -335,7 +335,7 @@ void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags); clear_bit(REQ_ATOM_POLL_SLEPT, &rq->atomic_flags); - blk_mq_put_tag(hctx, ctx, tag); + blk_mq_put_tag(hctx, hctx->tags, ctx, tag); blk_queue_exit(q); } diff --git a/block/blk-mq.h b/block/blk-mq.h index e59f5ca520a2..48b7771eb192 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -118,6 +118,11 @@ static inline void blk_mq_set_alloc_data(struct blk_mq_alloc_data *data, data->hctx = hctx; } +static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data) +{ + return data->hctx->tags; +} + /* * Internal helpers for request allocation/init/free */ From cc71a6f43886a8af57dbbce2a45b4b2aaf570fe6 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 11 Jan 2017 14:29:56 -0700 Subject: [PATCH 11/49] blk-mq: abstract out helpers for allocating/freeing tag maps Prep patch for adding an extra tag map for scheduler requests. Signed-off-by: Jens Axboe Reviewed-by: Bart Van Assche Reviewed-by: Omar Sandoval --- block/blk-mq.c | 117 +++++++++++++++++++++++++++++++------------------ block/blk-mq.h | 14 +++--- 2 files changed, 83 insertions(+), 48 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 6fab8e9c724f..fcdeadc55753 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1553,8 +1553,8 @@ run_queue: return cookie; } -void blk_mq_free_rq_map(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, - unsigned int hctx_idx) +void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, + unsigned int hctx_idx) { struct page *page; @@ -1580,33 +1580,30 @@ void blk_mq_free_rq_map(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, kmemleak_free(page_address(page)); __free_pages(page, page->private); } +} +void blk_mq_free_rq_map(struct blk_mq_tags *tags) +{ kfree(tags->rqs); + tags->rqs = NULL; blk_mq_free_tags(tags); } -static size_t order_to_size(unsigned int order) -{ - return (size_t)PAGE_SIZE << order; -} - -struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set, - unsigned int hctx_idx) +struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, + unsigned int hctx_idx, + unsigned int nr_tags, + unsigned int reserved_tags) { struct blk_mq_tags *tags; - unsigned int i, j, entries_per_page, max_order = 4; - size_t rq_size, left; - tags = blk_mq_init_tags(set->queue_depth, set->reserved_tags, + tags = blk_mq_init_tags(nr_tags, reserved_tags, set->numa_node, BLK_MQ_FLAG_TO_ALLOC_POLICY(set->flags)); if (!tags) return NULL; - INIT_LIST_HEAD(&tags->page_list); - - tags->rqs = kzalloc_node(set->queue_depth * sizeof(struct request *), + tags->rqs = kzalloc_node(nr_tags * sizeof(struct request *), GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY, set->numa_node); if (!tags->rqs) { @@ -1614,15 +1611,31 @@ struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set, return NULL; } + return tags; +} + +static size_t order_to_size(unsigned int order) +{ + return (size_t)PAGE_SIZE << order; +} + +int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, + unsigned int hctx_idx, unsigned int depth) +{ + unsigned int i, j, entries_per_page, max_order = 4; + size_t rq_size, left; + + INIT_LIST_HEAD(&tags->page_list); + /* * rq_size is the size of the request plus driver payload, rounded * to the cacheline size */ rq_size = round_up(sizeof(struct request) + set->cmd_size, cache_line_size()); - left = rq_size * set->queue_depth; + left = rq_size * depth; - for (i = 0; i < set->queue_depth; ) { + for (i = 0; i < depth; ) { int this_order = max_order; struct page *page; int to_do; @@ -1656,7 +1669,7 @@ struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set, */ kmemleak_alloc(p, order_to_size(this_order), 1, GFP_NOIO); entries_per_page = order_to_size(this_order) / rq_size; - to_do = min(entries_per_page, set->queue_depth - i); + to_do = min(entries_per_page, depth - i); left -= to_do * rq_size; for (j = 0; j < to_do; j++) { tags->rqs[i] = p; @@ -1673,11 +1686,11 @@ struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set, i++; } } - return tags; + return 0; fail: - blk_mq_free_rq_map(set, tags, hctx_idx); - return NULL; + blk_mq_free_rqs(set, tags, hctx_idx); + return -ENOMEM; } /* @@ -1869,6 +1882,33 @@ static void blk_mq_init_cpu_queues(struct request_queue *q, } } +static bool __blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, int hctx_idx) +{ + int ret = 0; + + set->tags[hctx_idx] = blk_mq_alloc_rq_map(set, hctx_idx, + set->queue_depth, set->reserved_tags); + if (!set->tags[hctx_idx]) + return false; + + ret = blk_mq_alloc_rqs(set, set->tags[hctx_idx], hctx_idx, + set->queue_depth); + if (!ret) + return true; + + blk_mq_free_rq_map(set->tags[hctx_idx]); + set->tags[hctx_idx] = NULL; + return false; +} + +static void blk_mq_free_map_and_requests(struct blk_mq_tag_set *set, + unsigned int hctx_idx) +{ + blk_mq_free_rqs(set, set->tags[hctx_idx], hctx_idx); + blk_mq_free_rq_map(set->tags[hctx_idx]); + set->tags[hctx_idx] = NULL; +} + static void blk_mq_map_swqueue(struct request_queue *q, const struct cpumask *online_mask) { @@ -1897,17 +1937,15 @@ static void blk_mq_map_swqueue(struct request_queue *q, hctx_idx = q->mq_map[i]; /* unmapped hw queue can be remapped after CPU topo changed */ - if (!set->tags[hctx_idx]) { - set->tags[hctx_idx] = blk_mq_init_rq_map(set, hctx_idx); - + if (!set->tags[hctx_idx] && + !__blk_mq_alloc_rq_map(set, hctx_idx)) { /* * If tags initialization fail for some hctx, * that hctx won't be brought online. In this * case, remap the current ctx to hctx[0] which * is guaranteed to always have tags allocated */ - if (!set->tags[hctx_idx]) - q->mq_map[i] = 0; + q->mq_map[i] = 0; } ctx = per_cpu_ptr(q->queue_ctx, i); @@ -1930,10 +1968,9 @@ static void blk_mq_map_swqueue(struct request_queue *q, * fallback in case of a new remap fails * allocation */ - if (i && set->tags[i]) { - blk_mq_free_rq_map(set, set->tags[i], i); - set->tags[i] = NULL; - } + if (i && set->tags[i]) + blk_mq_free_map_and_requests(set, i); + hctx->tags = NULL; continue; } @@ -2100,10 +2137,8 @@ static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set, struct blk_mq_hw_ctx *hctx = hctxs[j]; if (hctx) { - if (hctx->tags) { - blk_mq_free_rq_map(set, hctx->tags, j); - set->tags[j] = NULL; - } + if (hctx->tags) + blk_mq_free_map_and_requests(set, j); blk_mq_exit_hctx(q, set, hctx, j); free_cpumask_var(hctx->cpumask); kobject_put(&hctx->kobj); @@ -2299,17 +2334,15 @@ static int __blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set) { int i; - for (i = 0; i < set->nr_hw_queues; i++) { - set->tags[i] = blk_mq_init_rq_map(set, i); - if (!set->tags[i]) + for (i = 0; i < set->nr_hw_queues; i++) + if (!__blk_mq_alloc_rq_map(set, i)) goto out_unwind; - } return 0; out_unwind: while (--i >= 0) - blk_mq_free_rq_map(set, set->tags[i], i); + blk_mq_free_rq_map(set->tags[i]); return -ENOMEM; } @@ -2433,10 +2466,8 @@ void blk_mq_free_tag_set(struct blk_mq_tag_set *set) { int i; - for (i = 0; i < nr_cpu_ids; i++) { - if (set->tags[i]) - blk_mq_free_rq_map(set, set->tags[i], i); - } + for (i = 0; i < nr_cpu_ids; i++) + blk_mq_free_map_and_requests(set, i); kfree(set->mq_map); set->mq_map = NULL; diff --git a/block/blk-mq.h b/block/blk-mq.h index 48b7771eb192..1b279b02d0f6 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -37,17 +37,21 @@ void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list); /* * Internal helpers for allocating/freeing the request map */ -void blk_mq_free_rq_map(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, - unsigned int hctx_idx); -struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set, - unsigned int hctx_idx); +void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, + unsigned int hctx_idx); +void blk_mq_free_rq_map(struct blk_mq_tags *tags); +struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, + unsigned int hctx_idx, + unsigned int nr_tags, + unsigned int reserved_tags); +int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, + unsigned int hctx_idx, unsigned int depth); /* * Internal helpers for request insertion into sw queues */ void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, bool at_head); - /* * CPU hotplug helpers */ From fd2d332677c687ca90c12a47d6c377c547100b56 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 12 Jan 2017 10:04:45 -0700 Subject: [PATCH 12/49] blk-mq: add support for carrying internal tag information in blk_qc_t No functional change in this patch, just in preparation for having two types of tags available to the block layer for a single request. Signed-off-by: Jens Axboe Reviewed-by: Omar Sandoval --- block/blk-mq.c | 11 ++++++++--- include/linux/blk_types.h | 22 +++++++++++++++++----- 2 files changed, 25 insertions(+), 8 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index fcdeadc55753..d40be641f3d5 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1308,6 +1308,11 @@ static struct request *blk_mq_map_request(struct request_queue *q, return rq; } +static blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx, struct request *rq) +{ + return blk_tag_to_qc_t(rq->tag, hctx->queue_num, false); +} + static void blk_mq_try_issue_directly(struct request *rq, blk_qc_t *cookie) { int ret; @@ -1318,7 +1323,7 @@ static void blk_mq_try_issue_directly(struct request *rq, blk_qc_t *cookie) .list = NULL, .last = 1 }; - blk_qc_t new_cookie = blk_tag_to_qc_t(rq->tag, hctx->queue_num); + blk_qc_t new_cookie = request_to_qc_t(hctx, rq); if (blk_mq_hctx_stopped(hctx)) goto insert; @@ -1387,7 +1392,7 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) wbt_track(&rq->issue_stat, wb_acct); - cookie = blk_tag_to_qc_t(rq->tag, data.hctx->queue_num); + cookie = request_to_qc_t(data.hctx, rq); if (unlikely(is_flush_fua)) { blk_mq_bio_to_request(rq, bio); @@ -1496,7 +1501,7 @@ static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio) wbt_track(&rq->issue_stat, wb_acct); - cookie = blk_tag_to_qc_t(rq->tag, data.hctx->queue_num); + cookie = request_to_qc_t(data.hctx, rq); if (unlikely(is_flush_fua)) { blk_mq_bio_to_request(rq, bio); diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 519ea2c9df61..0e5b1cd5113c 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -232,22 +232,29 @@ static inline bool op_is_sync(unsigned int op) } typedef unsigned int blk_qc_t; -#define BLK_QC_T_NONE -1U -#define BLK_QC_T_SHIFT 16 +#define BLK_QC_T_NONE -1U +#define BLK_QC_T_SHIFT 16 +#define BLK_QC_T_INTERNAL (1U << 31) static inline bool blk_qc_t_valid(blk_qc_t cookie) { return cookie != BLK_QC_T_NONE; } -static inline blk_qc_t blk_tag_to_qc_t(unsigned int tag, unsigned int queue_num) +static inline blk_qc_t blk_tag_to_qc_t(unsigned int tag, unsigned int queue_num, + bool internal) { - return tag | (queue_num << BLK_QC_T_SHIFT); + blk_qc_t ret = tag | (queue_num << BLK_QC_T_SHIFT); + + if (internal) + ret |= BLK_QC_T_INTERNAL; + + return ret; } static inline unsigned int blk_qc_t_to_queue_num(blk_qc_t cookie) { - return cookie >> BLK_QC_T_SHIFT; + return (cookie & ~BLK_QC_T_INTERNAL) >> BLK_QC_T_SHIFT; } static inline unsigned int blk_qc_t_to_tag(blk_qc_t cookie) @@ -255,6 +262,11 @@ static inline unsigned int blk_qc_t_to_tag(blk_qc_t cookie) return cookie & ((1u << BLK_QC_T_SHIFT) - 1); } +static inline bool blk_qc_t_is_internal(blk_qc_t cookie) +{ + return (cookie & BLK_QC_T_INTERNAL) != 0; +} + struct blk_issue_stat { u64 time; }; From 2af8cbe30531eca73c8f3ba277f155fc0020b01a Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Fri, 13 Jan 2017 14:39:30 -0700 Subject: [PATCH 13/49] blk-mq: split tag ->rqs[] into two This is in preparation for having two sets of tags available. For that we need a static index, and a dynamically assignable one. Signed-off-by: Jens Axboe Reviewed-by: Omar Sandoval --- block/blk-mq-tag.c | 4 ++-- block/blk-mq-tag.h | 1 + block/blk-mq.c | 30 +++++++++++++++++++++++------- 3 files changed, 26 insertions(+), 9 deletions(-) diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index ced752716878..9753747a34a2 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -290,11 +290,11 @@ int blk_mq_reinit_tagset(struct blk_mq_tag_set *set) struct blk_mq_tags *tags = set->tags[i]; for (j = 0; j < tags->nr_tags; j++) { - if (!tags->rqs[j]) + if (!tags->static_rqs[j]) continue; ret = set->ops->reinit_request(set->driver_data, - tags->rqs[j]); + tags->static_rqs[j]); if (ret) goto out; } diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h index 923602dd3bfb..41cd15fd1afd 100644 --- a/block/blk-mq-tag.h +++ b/block/blk-mq-tag.h @@ -16,6 +16,7 @@ struct blk_mq_tags { struct sbitmap_queue breserved_tags; struct request **rqs; + struct request **static_rqs; struct list_head page_list; }; diff --git a/block/blk-mq.c b/block/blk-mq.c index d40be641f3d5..89b81254201b 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -223,7 +223,7 @@ struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data, tag = blk_mq_get_tag(data); if (tag != BLK_MQ_TAG_FAIL) { - rq = data->hctx->tags->rqs[tag]; + rq = data->hctx->tags->static_rqs[tag]; if (blk_mq_tag_busy(data->hctx)) { rq->rq_flags = RQF_MQ_INFLIGHT; @@ -231,6 +231,7 @@ struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data, } rq->tag = tag; + data->hctx->tags->rqs[tag] = rq; blk_mq_rq_ctx_init(data->q, data->ctx, rq, op); return rq; } @@ -1567,11 +1568,13 @@ void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, int i; for (i = 0; i < tags->nr_tags; i++) { - if (!tags->rqs[i]) + struct request *rq = tags->static_rqs[i]; + + if (!rq) continue; - set->ops->exit_request(set->driver_data, tags->rqs[i], + set->ops->exit_request(set->driver_data, rq, hctx_idx, i); - tags->rqs[i] = NULL; + tags->static_rqs[i] = NULL; } } @@ -1591,6 +1594,8 @@ void blk_mq_free_rq_map(struct blk_mq_tags *tags) { kfree(tags->rqs); tags->rqs = NULL; + kfree(tags->static_rqs); + tags->static_rqs = NULL; blk_mq_free_tags(tags); } @@ -1616,6 +1621,15 @@ struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, return NULL; } + tags->static_rqs = kzalloc_node(nr_tags * sizeof(struct request *), + GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY, + set->numa_node); + if (!tags->static_rqs) { + kfree(tags->rqs); + blk_mq_free_tags(tags); + return NULL; + } + return tags; } @@ -1677,12 +1691,14 @@ int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, to_do = min(entries_per_page, depth - i); left -= to_do * rq_size; for (j = 0; j < to_do; j++) { - tags->rqs[i] = p; + struct request *rq = p; + + tags->static_rqs[i] = rq; if (set->ops->init_request) { if (set->ops->init_request(set->driver_data, - tags->rqs[i], hctx_idx, i, + rq, hctx_idx, i, set->numa_node)) { - tags->rqs[i] = NULL; + tags->static_rqs[i] = NULL; goto fail; } } From bd166ef183c263c5ced656d49ef19c7da4adc774 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 17 Jan 2017 06:03:22 -0700 Subject: [PATCH 14/49] blk-mq-sched: add framework for MQ capable IO schedulers This adds a set of hooks that intercepts the blk-mq path of allocating/inserting/issuing/completing requests, allowing us to develop a scheduler within that framework. We reuse the existing elevator scheduler API on the registration side, but augment that with the scheduler flagging support for the blk-mq interfce, and with a separate set of ops hooks for MQ devices. We split driver and scheduler tags, so we can run the scheduling independently of device queue depth. Signed-off-by: Jens Axboe Reviewed-by: Bart Van Assche Reviewed-by: Omar Sandoval --- block/Makefile | 2 +- block/blk-cgroup.c | 24 ++- block/blk-core.c | 4 +- block/blk-exec.c | 3 +- block/blk-flush.c | 12 +- block/blk-ioc.c | 8 +- block/blk-merge.c | 2 +- block/blk-mq-sched.c | 368 +++++++++++++++++++++++++++++++++++++++ block/blk-mq-sched.h | 170 ++++++++++++++++++ block/blk-mq-sysfs.c | 13 ++ block/blk-mq.c | 318 +++++++++++++++++++-------------- block/blk-mq.h | 8 +- block/blk-tag.c | 1 + block/elevator.c | 202 ++++++++++++++++----- include/linux/blk-mq.h | 5 +- include/linux/blkdev.h | 4 +- include/linux/elevator.h | 32 ++++ 17 files changed, 983 insertions(+), 193 deletions(-) create mode 100644 block/blk-mq-sched.c create mode 100644 block/blk-mq-sched.h diff --git a/block/Makefile b/block/Makefile index a827f988c4e6..2eee9e1bb6db 100644 --- a/block/Makefile +++ b/block/Makefile @@ -6,7 +6,7 @@ obj-$(CONFIG_BLOCK) := bio.o elevator.o blk-core.o blk-tag.o blk-sysfs.o \ blk-flush.o blk-settings.o blk-ioc.o blk-map.o \ blk-exec.o blk-merge.o blk-softirq.o blk-timeout.o \ blk-lib.o blk-mq.o blk-mq-tag.o blk-stat.o \ - blk-mq-sysfs.o blk-mq-cpumap.o ioctl.o \ + blk-mq-sysfs.o blk-mq-cpumap.o blk-mq-sched.o ioctl.o \ genhd.o scsi_ioctl.o partition-generic.o ioprio.o \ badblocks.o partitions/ diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 8ba0af780e88..2630f64bed19 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -1223,7 +1223,11 @@ int blkcg_activate_policy(struct request_queue *q, if (blkcg_policy_enabled(q, pol)) return 0; - blk_queue_bypass_start(q); + if (q->mq_ops) { + blk_mq_freeze_queue(q); + blk_mq_quiesce_queue(q); + } else + blk_queue_bypass_start(q); pd_prealloc: if (!pd_prealloc) { pd_prealloc = pol->pd_alloc_fn(GFP_KERNEL, q->node); @@ -1261,7 +1265,10 @@ pd_prealloc: spin_unlock_irq(q->queue_lock); out_bypass_end: - blk_queue_bypass_end(q); + if (q->mq_ops) + blk_mq_unfreeze_queue(q); + else + blk_queue_bypass_end(q); if (pd_prealloc) pol->pd_free_fn(pd_prealloc); return ret; @@ -1284,7 +1291,12 @@ void blkcg_deactivate_policy(struct request_queue *q, if (!blkcg_policy_enabled(q, pol)) return; - blk_queue_bypass_start(q); + if (q->mq_ops) { + blk_mq_freeze_queue(q); + blk_mq_quiesce_queue(q); + } else + blk_queue_bypass_start(q); + spin_lock_irq(q->queue_lock); __clear_bit(pol->plid, q->blkcg_pols); @@ -1304,7 +1316,11 @@ void blkcg_deactivate_policy(struct request_queue *q, } spin_unlock_irq(q->queue_lock); - blk_queue_bypass_end(q); + + if (q->mq_ops) + blk_mq_unfreeze_queue(q); + else + blk_queue_bypass_end(q); } EXPORT_SYMBOL_GPL(blkcg_deactivate_policy); diff --git a/block/blk-core.c b/block/blk-core.c index 92baea07acbc..a61f1407f4f6 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -39,6 +39,7 @@ #include "blk.h" #include "blk-mq.h" +#include "blk-mq-sched.h" #include "blk-wbt.h" EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_remap); @@ -134,6 +135,7 @@ void blk_rq_init(struct request_queue *q, struct request *rq) rq->cmd = rq->__cmd; rq->cmd_len = BLK_MAX_CDB; rq->tag = -1; + rq->internal_tag = -1; rq->start_time = jiffies; set_start_time_ns(rq); rq->part = NULL; @@ -2127,7 +2129,7 @@ int blk_insert_cloned_request(struct request_queue *q, struct request *rq) if (q->mq_ops) { if (blk_queue_io_stat(q)) blk_account_io_start(rq, true); - blk_mq_insert_request(rq, false, true, false); + blk_mq_sched_insert_request(rq, false, true, false); return 0; } diff --git a/block/blk-exec.c b/block/blk-exec.c index 3ecb00a6cf45..86656fdfa637 100644 --- a/block/blk-exec.c +++ b/block/blk-exec.c @@ -9,6 +9,7 @@ #include #include "blk.h" +#include "blk-mq-sched.h" /* * for max sense size @@ -65,7 +66,7 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk, * be reused after dying flag is set */ if (q->mq_ops) { - blk_mq_insert_request(rq, at_head, true, false); + blk_mq_sched_insert_request(rq, at_head, true, false); return; } diff --git a/block/blk-flush.c b/block/blk-flush.c index 20b7c7a02f1c..d7de34ee39c2 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -74,6 +74,7 @@ #include "blk.h" #include "blk-mq.h" #include "blk-mq-tag.h" +#include "blk-mq-sched.h" /* FLUSH/FUA sequences */ enum { @@ -391,9 +392,10 @@ static void mq_flush_data_end_io(struct request *rq, int error) * the comment in flush_end_io(). */ spin_lock_irqsave(&fq->mq_flush_lock, flags); - if (blk_flush_complete_seq(rq, fq, REQ_FSEQ_DATA, error)) - blk_mq_run_hw_queue(hctx, true); + blk_flush_complete_seq(rq, fq, REQ_FSEQ_DATA, error); spin_unlock_irqrestore(&fq->mq_flush_lock, flags); + + blk_mq_run_hw_queue(hctx, true); } /** @@ -453,9 +455,9 @@ void blk_insert_flush(struct request *rq) */ if ((policy & REQ_FSEQ_DATA) && !(policy & (REQ_FSEQ_PREFLUSH | REQ_FSEQ_POSTFLUSH))) { - if (q->mq_ops) { - blk_mq_insert_request(rq, false, true, false); - } else + if (q->mq_ops) + blk_mq_sched_insert_request(rq, false, true, false); + else list_add_tail(&rq->queuelist, &q->queue_head); return; } diff --git a/block/blk-ioc.c b/block/blk-ioc.c index ab372092a57d..fe186a9eade9 100644 --- a/block/blk-ioc.c +++ b/block/blk-ioc.c @@ -43,7 +43,9 @@ static void ioc_exit_icq(struct io_cq *icq) if (icq->flags & ICQ_EXITED) return; - if (et->ops.sq.elevator_exit_icq_fn) + if (et->uses_mq && et->ops.mq.exit_icq) + et->ops.mq.exit_icq(icq); + else if (!et->uses_mq && et->ops.sq.elevator_exit_icq_fn) et->ops.sq.elevator_exit_icq_fn(icq); icq->flags |= ICQ_EXITED; @@ -383,7 +385,9 @@ struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q, if (likely(!radix_tree_insert(&ioc->icq_tree, q->id, icq))) { hlist_add_head(&icq->ioc_node, &ioc->icq_list); list_add(&icq->q_node, &q->icq_list); - if (et->ops.sq.elevator_init_icq_fn) + if (et->uses_mq && et->ops.mq.init_icq) + et->ops.mq.init_icq(icq); + else if (!et->uses_mq && et->ops.sq.elevator_init_icq_fn) et->ops.sq.elevator_init_icq_fn(icq); } else { kmem_cache_free(et->icq_cache, icq); diff --git a/block/blk-merge.c b/block/blk-merge.c index 480570b691dc..6aa43dec5af4 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -763,7 +763,7 @@ int blk_attempt_req_merge(struct request_queue *q, struct request *rq, { struct elevator_queue *e = q->elevator; - if (e->type->ops.sq.elevator_allow_rq_merge_fn) + if (!e->uses_mq && e->type->ops.sq.elevator_allow_rq_merge_fn) if (!e->type->ops.sq.elevator_allow_rq_merge_fn(q, rq, next)) return 0; diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c new file mode 100644 index 000000000000..26759798a0b3 --- /dev/null +++ b/block/blk-mq-sched.c @@ -0,0 +1,368 @@ +/* + * blk-mq scheduling framework + * + * Copyright (C) 2016 Jens Axboe + */ +#include +#include +#include + +#include + +#include "blk.h" +#include "blk-mq.h" +#include "blk-mq-sched.h" +#include "blk-mq-tag.h" +#include "blk-wbt.h" + +void blk_mq_sched_free_hctx_data(struct request_queue *q, + void (*exit)(struct blk_mq_hw_ctx *)) +{ + struct blk_mq_hw_ctx *hctx; + int i; + + queue_for_each_hw_ctx(q, hctx, i) { + if (exit && hctx->sched_data) + exit(hctx); + kfree(hctx->sched_data); + hctx->sched_data = NULL; + } +} +EXPORT_SYMBOL_GPL(blk_mq_sched_free_hctx_data); + +int blk_mq_sched_init_hctx_data(struct request_queue *q, size_t size, + int (*init)(struct blk_mq_hw_ctx *), + void (*exit)(struct blk_mq_hw_ctx *)) +{ + struct blk_mq_hw_ctx *hctx; + int ret; + int i; + + queue_for_each_hw_ctx(q, hctx, i) { + hctx->sched_data = kmalloc_node(size, GFP_KERNEL, hctx->numa_node); + if (!hctx->sched_data) { + ret = -ENOMEM; + goto error; + } + + if (init) { + ret = init(hctx); + if (ret) { + /* + * We don't want to give exit() a partially + * initialized sched_data. init() must clean up + * if it fails. + */ + kfree(hctx->sched_data); + hctx->sched_data = NULL; + goto error; + } + } + } + + return 0; +error: + blk_mq_sched_free_hctx_data(q, exit); + return ret; +} +EXPORT_SYMBOL_GPL(blk_mq_sched_init_hctx_data); + +static void __blk_mq_sched_assign_ioc(struct request_queue *q, + struct request *rq, struct io_context *ioc) +{ + struct io_cq *icq; + + spin_lock_irq(q->queue_lock); + icq = ioc_lookup_icq(ioc, q); + spin_unlock_irq(q->queue_lock); + + if (!icq) { + icq = ioc_create_icq(ioc, q, GFP_ATOMIC); + if (!icq) + return; + } + + rq->elv.icq = icq; + if (!blk_mq_sched_get_rq_priv(q, rq)) { + rq->rq_flags |= RQF_ELVPRIV; + get_io_context(icq->ioc); + return; + } + + rq->elv.icq = NULL; +} + +static void blk_mq_sched_assign_ioc(struct request_queue *q, + struct request *rq, struct bio *bio) +{ + struct io_context *ioc; + + ioc = rq_ioc(bio); + if (ioc) + __blk_mq_sched_assign_ioc(q, rq, ioc); +} + +struct request *blk_mq_sched_get_request(struct request_queue *q, + struct bio *bio, + unsigned int op, + struct blk_mq_alloc_data *data) +{ + struct elevator_queue *e = q->elevator; + struct blk_mq_hw_ctx *hctx; + struct blk_mq_ctx *ctx; + struct request *rq; + const bool is_flush = op & (REQ_PREFLUSH | REQ_FUA); + + blk_queue_enter_live(q); + ctx = blk_mq_get_ctx(q); + hctx = blk_mq_map_queue(q, ctx->cpu); + + blk_mq_set_alloc_data(data, q, 0, ctx, hctx); + + if (e) { + data->flags |= BLK_MQ_REQ_INTERNAL; + + /* + * Flush requests are special and go directly to the + * dispatch list. + */ + if (!is_flush && e->type->ops.mq.get_request) { + rq = e->type->ops.mq.get_request(q, op, data); + if (rq) + rq->rq_flags |= RQF_QUEUED; + } else + rq = __blk_mq_alloc_request(data, op); + } else { + rq = __blk_mq_alloc_request(data, op); + data->hctx->tags->rqs[rq->tag] = rq; + } + + if (rq) { + if (!is_flush) { + rq->elv.icq = NULL; + if (e && e->type->icq_cache) + blk_mq_sched_assign_ioc(q, rq, bio); + } + data->hctx->queued++; + return rq; + } + + blk_queue_exit(q); + return NULL; +} + +void blk_mq_sched_put_request(struct request *rq) +{ + struct request_queue *q = rq->q; + struct elevator_queue *e = q->elevator; + + if (rq->rq_flags & RQF_ELVPRIV) { + blk_mq_sched_put_rq_priv(rq->q, rq); + if (rq->elv.icq) { + put_io_context(rq->elv.icq->ioc); + rq->elv.icq = NULL; + } + } + + if ((rq->rq_flags & RQF_QUEUED) && e && e->type->ops.mq.put_request) + e->type->ops.mq.put_request(rq); + else + blk_mq_finish_request(rq); +} + +void blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx) +{ + struct elevator_queue *e = hctx->queue->elevator; + LIST_HEAD(rq_list); + + if (unlikely(blk_mq_hctx_stopped(hctx))) + return; + + hctx->run++; + + /* + * If we have previous entries on our dispatch list, grab them first for + * more fair dispatch. + */ + if (!list_empty_careful(&hctx->dispatch)) { + spin_lock(&hctx->lock); + if (!list_empty(&hctx->dispatch)) + list_splice_init(&hctx->dispatch, &rq_list); + spin_unlock(&hctx->lock); + } + + /* + * Only ask the scheduler for requests, if we didn't have residual + * requests from the dispatch list. This is to avoid the case where + * we only ever dispatch a fraction of the requests available because + * of low device queue depth. Once we pull requests out of the IO + * scheduler, we can no longer merge or sort them. So it's best to + * leave them there for as long as we can. Mark the hw queue as + * needing a restart in that case. + */ + if (list_empty(&rq_list)) { + if (e && e->type->ops.mq.dispatch_requests) + e->type->ops.mq.dispatch_requests(hctx, &rq_list); + else + blk_mq_flush_busy_ctxs(hctx, &rq_list); + } else + blk_mq_sched_mark_restart(hctx); + + blk_mq_dispatch_rq_list(hctx, &rq_list); +} + +void blk_mq_sched_move_to_dispatch(struct blk_mq_hw_ctx *hctx, + struct list_head *rq_list, + struct request *(*get_rq)(struct blk_mq_hw_ctx *)) +{ + do { + struct request *rq; + + rq = get_rq(hctx); + if (!rq) + break; + + list_add_tail(&rq->queuelist, rq_list); + } while (1); +} +EXPORT_SYMBOL_GPL(blk_mq_sched_move_to_dispatch); + +bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio) +{ + struct request *rq; + int ret; + + ret = elv_merge(q, &rq, bio); + if (ret == ELEVATOR_BACK_MERGE) { + if (!blk_mq_sched_allow_merge(q, rq, bio)) + return false; + if (bio_attempt_back_merge(q, rq, bio)) { + if (!attempt_back_merge(q, rq)) + elv_merged_request(q, rq, ret); + return true; + } + } else if (ret == ELEVATOR_FRONT_MERGE) { + if (!blk_mq_sched_allow_merge(q, rq, bio)) + return false; + if (bio_attempt_front_merge(q, rq, bio)) { + if (!attempt_front_merge(q, rq)) + elv_merged_request(q, rq, ret); + return true; + } + } + + return false; +} +EXPORT_SYMBOL_GPL(blk_mq_sched_try_merge); + +bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio) +{ + struct elevator_queue *e = q->elevator; + + if (e->type->ops.mq.bio_merge) { + struct blk_mq_ctx *ctx = blk_mq_get_ctx(q); + struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); + + blk_mq_put_ctx(ctx); + return e->type->ops.mq.bio_merge(hctx, bio); + } + + return false; +} + +bool blk_mq_sched_try_insert_merge(struct request_queue *q, struct request *rq) +{ + return rq_mergeable(rq) && elv_attempt_insert_merge(q, rq); +} +EXPORT_SYMBOL_GPL(blk_mq_sched_try_insert_merge); + +void blk_mq_sched_request_inserted(struct request *rq) +{ + trace_block_rq_insert(rq->q, rq); +} +EXPORT_SYMBOL_GPL(blk_mq_sched_request_inserted); + +bool blk_mq_sched_bypass_insert(struct blk_mq_hw_ctx *hctx, struct request *rq) +{ + if (rq->tag == -1) { + rq->rq_flags |= RQF_SORTED; + return false; + } + + /* + * If we already have a real request tag, send directly to + * the dispatch list. + */ + spin_lock(&hctx->lock); + list_add(&rq->queuelist, &hctx->dispatch); + spin_unlock(&hctx->lock); + return true; +} +EXPORT_SYMBOL_GPL(blk_mq_sched_bypass_insert); + +static void blk_mq_sched_free_tags(struct blk_mq_tag_set *set, + struct blk_mq_hw_ctx *hctx, + unsigned int hctx_idx) +{ + if (hctx->sched_tags) { + blk_mq_free_rqs(set, hctx->sched_tags, hctx_idx); + blk_mq_free_rq_map(hctx->sched_tags); + hctx->sched_tags = NULL; + } +} + +int blk_mq_sched_setup(struct request_queue *q) +{ + struct blk_mq_tag_set *set = q->tag_set; + struct blk_mq_hw_ctx *hctx; + int ret, i; + + /* + * Default to 256, since we don't split into sync/async like the + * old code did. Additionally, this is a per-hw queue depth. + */ + q->nr_requests = 2 * BLKDEV_MAX_RQ; + + /* + * We're switching to using an IO scheduler, so setup the hctx + * scheduler tags and switch the request map from the regular + * tags to scheduler tags. First allocate what we need, so we + * can safely fail and fallback, if needed. + */ + ret = 0; + queue_for_each_hw_ctx(q, hctx, i) { + hctx->sched_tags = blk_mq_alloc_rq_map(set, i, q->nr_requests, 0); + if (!hctx->sched_tags) { + ret = -ENOMEM; + break; + } + ret = blk_mq_alloc_rqs(set, hctx->sched_tags, i, q->nr_requests); + if (ret) + break; + } + + /* + * If we failed, free what we did allocate + */ + if (ret) { + queue_for_each_hw_ctx(q, hctx, i) { + if (!hctx->sched_tags) + continue; + blk_mq_sched_free_tags(set, hctx, i); + } + + return ret; + } + + return 0; +} + +void blk_mq_sched_teardown(struct request_queue *q) +{ + struct blk_mq_tag_set *set = q->tag_set; + struct blk_mq_hw_ctx *hctx; + int i; + + queue_for_each_hw_ctx(q, hctx, i) + blk_mq_sched_free_tags(set, hctx, i); +} diff --git a/block/blk-mq-sched.h b/block/blk-mq-sched.h new file mode 100644 index 000000000000..35c49e2e008a --- /dev/null +++ b/block/blk-mq-sched.h @@ -0,0 +1,170 @@ +#ifndef BLK_MQ_SCHED_H +#define BLK_MQ_SCHED_H + +#include "blk-mq.h" +#include "blk-mq-tag.h" + +int blk_mq_sched_init_hctx_data(struct request_queue *q, size_t size, + int (*init)(struct blk_mq_hw_ctx *), + void (*exit)(struct blk_mq_hw_ctx *)); + +void blk_mq_sched_free_hctx_data(struct request_queue *q, + void (*exit)(struct blk_mq_hw_ctx *)); + +struct request *blk_mq_sched_get_request(struct request_queue *q, struct bio *bio, unsigned int op, struct blk_mq_alloc_data *data); +void blk_mq_sched_put_request(struct request *rq); + +void blk_mq_sched_request_inserted(struct request *rq); +bool blk_mq_sched_bypass_insert(struct blk_mq_hw_ctx *hctx, struct request *rq); +bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio); +bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio); +bool blk_mq_sched_try_insert_merge(struct request_queue *q, struct request *rq); + +void blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx); +void blk_mq_sched_move_to_dispatch(struct blk_mq_hw_ctx *hctx, + struct list_head *rq_list, + struct request *(*get_rq)(struct blk_mq_hw_ctx *)); + +int blk_mq_sched_setup(struct request_queue *q); +void blk_mq_sched_teardown(struct request_queue *q); + +static inline bool +blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio) +{ + struct elevator_queue *e = q->elevator; + + if (!e || blk_queue_nomerges(q) || !bio_mergeable(bio)) + return false; + + return __blk_mq_sched_bio_merge(q, bio); +} + +static inline int blk_mq_sched_get_rq_priv(struct request_queue *q, + struct request *rq) +{ + struct elevator_queue *e = q->elevator; + + if (e && e->type->ops.mq.get_rq_priv) + return e->type->ops.mq.get_rq_priv(q, rq); + + return 0; +} + +static inline void blk_mq_sched_put_rq_priv(struct request_queue *q, + struct request *rq) +{ + struct elevator_queue *e = q->elevator; + + if (e && e->type->ops.mq.put_rq_priv) + e->type->ops.mq.put_rq_priv(q, rq); +} + +static inline void +blk_mq_sched_insert_request(struct request *rq, bool at_head, bool run_queue, + bool async) +{ + struct request_queue *q = rq->q; + struct elevator_queue *e = q->elevator; + struct blk_mq_ctx *ctx = rq->mq_ctx; + struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); + + if (e && e->type->ops.mq.insert_requests) { + LIST_HEAD(list); + + list_add(&rq->queuelist, &list); + e->type->ops.mq.insert_requests(hctx, &list, at_head); + } else { + spin_lock(&ctx->lock); + __blk_mq_insert_request(hctx, rq, at_head); + spin_unlock(&ctx->lock); + } + + if (run_queue) + blk_mq_run_hw_queue(hctx, async); +} + +static inline void +blk_mq_sched_insert_requests(struct request_queue *q, struct blk_mq_ctx *ctx, + struct list_head *list, bool run_queue_async) +{ + struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); + struct elevator_queue *e = hctx->queue->elevator; + + if (e && e->type->ops.mq.insert_requests) + e->type->ops.mq.insert_requests(hctx, list, false); + else + blk_mq_insert_requests(hctx, ctx, list); + + blk_mq_run_hw_queue(hctx, run_queue_async); +} + +static inline bool +blk_mq_sched_allow_merge(struct request_queue *q, struct request *rq, + struct bio *bio) +{ + struct elevator_queue *e = q->elevator; + + if (e && e->type->ops.mq.allow_merge) + return e->type->ops.mq.allow_merge(q, rq, bio); + + return true; +} + +static inline void +blk_mq_sched_completed_request(struct blk_mq_hw_ctx *hctx, struct request *rq) +{ + struct elevator_queue *e = hctx->queue->elevator; + + if (e && e->type->ops.mq.completed_request) + e->type->ops.mq.completed_request(hctx, rq); + + BUG_ON(rq->internal_tag == -1); + + blk_mq_put_tag(hctx, hctx->sched_tags, rq->mq_ctx, rq->internal_tag); + + if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state)) { + clear_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state); + blk_mq_run_hw_queue(hctx, true); + } +} + +static inline void blk_mq_sched_started_request(struct request *rq) +{ + struct request_queue *q = rq->q; + struct elevator_queue *e = q->elevator; + + if (e && e->type->ops.mq.started_request) + e->type->ops.mq.started_request(rq); +} + +static inline void blk_mq_sched_requeue_request(struct request *rq) +{ + struct request_queue *q = rq->q; + struct elevator_queue *e = q->elevator; + + if (e && e->type->ops.mq.requeue_request) + e->type->ops.mq.requeue_request(rq); +} + +static inline bool blk_mq_sched_has_work(struct blk_mq_hw_ctx *hctx) +{ + struct elevator_queue *e = hctx->queue->elevator; + + if (e && e->type->ops.mq.has_work) + return e->type->ops.mq.has_work(hctx); + + return false; +} + +static inline void blk_mq_sched_mark_restart(struct blk_mq_hw_ctx *hctx) +{ + if (!test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state)) + set_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state); +} + +static inline bool blk_mq_sched_needs_restart(struct blk_mq_hw_ctx *hctx) +{ + return test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state); +} + +#endif diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c index eacd3af72099..2caecaa98e40 100644 --- a/block/blk-mq-sysfs.c +++ b/block/blk-mq-sysfs.c @@ -231,6 +231,14 @@ static ssize_t blk_mq_hw_sysfs_rq_list_show(struct blk_mq_hw_ctx *hctx, return ret; } +static ssize_t blk_mq_hw_sysfs_sched_tags_show(struct blk_mq_hw_ctx *hctx, char *page) +{ + if (hctx->sched_tags) + return blk_mq_tag_sysfs_show(hctx->sched_tags, page); + + return 0; +} + static ssize_t blk_mq_hw_sysfs_tags_show(struct blk_mq_hw_ctx *hctx, char *page) { return blk_mq_tag_sysfs_show(hctx->tags, page); @@ -345,6 +353,10 @@ static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_pending = { .attr = {.name = "pending", .mode = S_IRUGO }, .show = blk_mq_hw_sysfs_rq_list_show, }; +static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_sched_tags = { + .attr = {.name = "sched_tags", .mode = S_IRUGO }, + .show = blk_mq_hw_sysfs_sched_tags_show, +}; static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_tags = { .attr = {.name = "tags", .mode = S_IRUGO }, .show = blk_mq_hw_sysfs_tags_show, @@ -370,6 +382,7 @@ static struct attribute *default_hw_ctx_attrs[] = { &blk_mq_hw_sysfs_dispatched.attr, &blk_mq_hw_sysfs_pending.attr, &blk_mq_hw_sysfs_tags.attr, + &blk_mq_hw_sysfs_sched_tags.attr, &blk_mq_hw_sysfs_cpus.attr, &blk_mq_hw_sysfs_active.attr, &blk_mq_hw_sysfs_poll.attr, diff --git a/block/blk-mq.c b/block/blk-mq.c index 89b81254201b..45e1707a9f86 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -32,6 +32,7 @@ #include "blk-mq-tag.h" #include "blk-stat.h" #include "blk-wbt.h" +#include "blk-mq-sched.h" static DEFINE_MUTEX(all_q_mutex); static LIST_HEAD(all_q_list); @@ -41,7 +42,9 @@ static LIST_HEAD(all_q_list); */ static bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx) { - return sbitmap_any_bit_set(&hctx->ctx_map); + return sbitmap_any_bit_set(&hctx->ctx_map) || + !list_empty_careful(&hctx->dispatch) || + blk_mq_sched_has_work(hctx); } /* @@ -223,15 +226,23 @@ struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data, tag = blk_mq_get_tag(data); if (tag != BLK_MQ_TAG_FAIL) { - rq = data->hctx->tags->static_rqs[tag]; + struct blk_mq_tags *tags = blk_mq_tags_from_data(data); + + rq = tags->static_rqs[tag]; if (blk_mq_tag_busy(data->hctx)) { rq->rq_flags = RQF_MQ_INFLIGHT; atomic_inc(&data->hctx->nr_active); } - rq->tag = tag; - data->hctx->tags->rqs[tag] = rq; + if (data->flags & BLK_MQ_REQ_INTERNAL) { + rq->tag = -1; + rq->internal_tag = tag; + } else { + rq->tag = tag; + rq->internal_tag = -1; + } + blk_mq_rq_ctx_init(data->q, data->ctx, rq, op); return rq; } @@ -243,26 +254,21 @@ EXPORT_SYMBOL_GPL(__blk_mq_alloc_request); struct request *blk_mq_alloc_request(struct request_queue *q, int rw, unsigned int flags) { - struct blk_mq_ctx *ctx; - struct blk_mq_hw_ctx *hctx; - struct request *rq; struct blk_mq_alloc_data alloc_data; + struct request *rq; int ret; ret = blk_queue_enter(q, flags & BLK_MQ_REQ_NOWAIT); if (ret) return ERR_PTR(ret); - ctx = blk_mq_get_ctx(q); - hctx = blk_mq_map_queue(q, ctx->cpu); - blk_mq_set_alloc_data(&alloc_data, q, flags, ctx, hctx); - rq = __blk_mq_alloc_request(&alloc_data, rw); - blk_mq_put_ctx(ctx); + rq = blk_mq_sched_get_request(q, NULL, rw, &alloc_data); - if (!rq) { - blk_queue_exit(q); + blk_mq_put_ctx(alloc_data.ctx); + blk_queue_exit(q); + + if (!rq) return ERR_PTR(-EWOULDBLOCK); - } rq->__data_len = 0; rq->__sector = (sector_t) -1; @@ -322,10 +328,10 @@ out_queue_exit: } EXPORT_SYMBOL_GPL(blk_mq_alloc_request_hctx); -void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, - struct request *rq) +void __blk_mq_finish_request(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, + struct request *rq) { - const int tag = rq->tag; + const int sched_tag = rq->internal_tag; struct request_queue *q = rq->q; if (rq->rq_flags & RQF_MQ_INFLIGHT) @@ -336,22 +342,30 @@ void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags); clear_bit(REQ_ATOM_POLL_SLEPT, &rq->atomic_flags); - blk_mq_put_tag(hctx, hctx->tags, ctx, tag); + if (rq->tag != -1) + blk_mq_put_tag(hctx, hctx->tags, ctx, rq->tag); + if (sched_tag != -1) + blk_mq_sched_completed_request(hctx, rq); blk_queue_exit(q); } -static void blk_mq_free_hctx_request(struct blk_mq_hw_ctx *hctx, +static void blk_mq_finish_hctx_request(struct blk_mq_hw_ctx *hctx, struct request *rq) { struct blk_mq_ctx *ctx = rq->mq_ctx; ctx->rq_completed[rq_is_sync(rq)]++; - __blk_mq_free_request(hctx, ctx, rq); + __blk_mq_finish_request(hctx, ctx, rq); +} + +void blk_mq_finish_request(struct request *rq) +{ + blk_mq_finish_hctx_request(blk_mq_map_queue(rq->q, rq->mq_ctx->cpu), rq); } void blk_mq_free_request(struct request *rq) { - blk_mq_free_hctx_request(blk_mq_map_queue(rq->q, rq->mq_ctx->cpu), rq); + blk_mq_sched_put_request(rq); } EXPORT_SYMBOL_GPL(blk_mq_free_request); @@ -469,6 +483,8 @@ void blk_mq_start_request(struct request *rq) { struct request_queue *q = rq->q; + blk_mq_sched_started_request(rq); + trace_block_rq_issue(q, rq); rq->resid_len = blk_rq_bytes(rq); @@ -517,6 +533,7 @@ static void __blk_mq_requeue_request(struct request *rq) trace_block_rq_requeue(q, rq); wbt_requeue(q->rq_wb, &rq->issue_stat); + blk_mq_sched_requeue_request(rq); if (test_and_clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) { if (q->dma_drain_size && blk_rq_bytes(rq)) @@ -551,13 +568,13 @@ static void blk_mq_requeue_work(struct work_struct *work) rq->rq_flags &= ~RQF_SOFTBARRIER; list_del_init(&rq->queuelist); - blk_mq_insert_request(rq, true, false, false); + blk_mq_sched_insert_request(rq, true, false, false); } while (!list_empty(&rq_list)) { rq = list_entry(rq_list.next, struct request, queuelist); list_del_init(&rq->queuelist); - blk_mq_insert_request(rq, false, false, false); + blk_mq_sched_insert_request(rq, false, false, false); } blk_mq_run_hw_queues(q, false); @@ -765,6 +782,12 @@ static bool blk_mq_attempt_merge(struct request_queue *q, continue; el_ret = blk_try_merge(rq, bio); + if (el_ret == ELEVATOR_NO_MERGE) + continue; + + if (!blk_mq_sched_allow_merge(q, rq, bio)) + break; + if (el_ret == ELEVATOR_BACK_MERGE) { if (bio_attempt_back_merge(q, rq, bio)) { ctx->rq_merged++; @@ -824,6 +847,59 @@ static inline unsigned int queued_to_index(unsigned int queued) return min(BLK_MQ_MAX_DISPATCH_ORDER - 1, ilog2(queued) + 1); } +static bool blk_mq_get_driver_tag(struct request *rq, + struct blk_mq_hw_ctx **hctx, bool wait) +{ + struct blk_mq_alloc_data data = { + .q = rq->q, + .ctx = rq->mq_ctx, + .hctx = blk_mq_map_queue(rq->q, rq->mq_ctx->cpu), + .flags = wait ? 0 : BLK_MQ_REQ_NOWAIT, + }; + + if (blk_mq_hctx_stopped(data.hctx)) + return false; + + if (rq->tag != -1) { +done: + if (hctx) + *hctx = data.hctx; + return true; + } + + rq->tag = blk_mq_get_tag(&data); + if (rq->tag >= 0) { + data.hctx->tags->rqs[rq->tag] = rq; + goto done; + } + + return false; +} + +/* + * If we fail getting a driver tag because all the driver tags are already + * assigned and on the dispatch list, BUT the first entry does not have a + * tag, then we could deadlock. For that case, move entries with assigned + * driver tags to the front, leaving the set of tagged requests in the + * same order, and the untagged set in the same order. + */ +static bool reorder_tags_to_front(struct list_head *list) +{ + struct request *rq, *tmp, *first = NULL; + + list_for_each_entry_safe_reverse(rq, tmp, list, queuelist) { + if (rq == first) + break; + if (rq->tag != -1) { + list_move(&rq->queuelist, list); + if (!first) + first = rq; + } + } + + return first != NULL; +} + bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list) { struct request_queue *q = hctx->queue; @@ -846,6 +922,12 @@ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list) struct blk_mq_queue_data bd; rq = list_first_entry(list, struct request, queuelist); + if (!blk_mq_get_driver_tag(rq, &hctx, false)) { + if (!queued && reorder_tags_to_front(list)) + continue; + blk_mq_sched_mark_restart(hctx); + break; + } list_del_init(&rq->queuelist); bd.rq = rq; @@ -899,48 +981,17 @@ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list) * the requests in rq_list might get lost. * * blk_mq_run_hw_queue() already checks the STOPPED bit - **/ - blk_mq_run_hw_queue(hctx, true); + * + * If RESTART is set, then let completion restart the queue + * instead of potentially looping here. + */ + if (!blk_mq_sched_needs_restart(hctx)) + blk_mq_run_hw_queue(hctx, true); } return ret != BLK_MQ_RQ_QUEUE_BUSY; } -/* - * Run this hardware queue, pulling any software queues mapped to it in. - * Note that this function currently has various problems around ordering - * of IO. In particular, we'd like FIFO behaviour on handling existing - * items on the hctx->dispatch list. Ignore that for now. - */ -static void blk_mq_process_rq_list(struct blk_mq_hw_ctx *hctx) -{ - LIST_HEAD(rq_list); - LIST_HEAD(driver_list); - - if (unlikely(blk_mq_hctx_stopped(hctx))) - return; - - hctx->run++; - - /* - * Touch any software queue that has pending entries. - */ - blk_mq_flush_busy_ctxs(hctx, &rq_list); - - /* - * If we have previous entries on our dispatch list, grab them - * and stuff them at the front for more fair dispatch. - */ - if (!list_empty_careful(&hctx->dispatch)) { - spin_lock(&hctx->lock); - if (!list_empty(&hctx->dispatch)) - list_splice_init(&hctx->dispatch, &rq_list); - spin_unlock(&hctx->lock); - } - - blk_mq_dispatch_rq_list(hctx, &rq_list); -} - static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) { int srcu_idx; @@ -950,11 +1001,11 @@ static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) if (!(hctx->flags & BLK_MQ_F_BLOCKING)) { rcu_read_lock(); - blk_mq_process_rq_list(hctx); + blk_mq_sched_dispatch_requests(hctx); rcu_read_unlock(); } else { srcu_idx = srcu_read_lock(&hctx->queue_rq_srcu); - blk_mq_process_rq_list(hctx); + blk_mq_sched_dispatch_requests(hctx); srcu_read_unlock(&hctx->queue_rq_srcu, srcu_idx); } } @@ -1010,8 +1061,7 @@ void blk_mq_run_hw_queues(struct request_queue *q, bool async) int i; queue_for_each_hw_ctx(q, hctx, i) { - if ((!blk_mq_hctx_has_pending(hctx) && - list_empty_careful(&hctx->dispatch)) || + if (!blk_mq_hctx_has_pending(hctx) || blk_mq_hctx_stopped(hctx)) continue; @@ -1148,32 +1198,10 @@ void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, blk_mq_hctx_mark_pending(hctx, ctx); } -void blk_mq_insert_request(struct request *rq, bool at_head, bool run_queue, - bool async) -{ - struct blk_mq_ctx *ctx = rq->mq_ctx; - struct request_queue *q = rq->q; - struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); - - spin_lock(&ctx->lock); - __blk_mq_insert_request(hctx, rq, at_head); - spin_unlock(&ctx->lock); - - if (run_queue) - blk_mq_run_hw_queue(hctx, async); -} - -static void blk_mq_insert_requests(struct request_queue *q, - struct blk_mq_ctx *ctx, - struct list_head *list, - int depth, - bool from_schedule) +void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, + struct list_head *list) { - struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); - - trace_block_unplug(q, depth, !from_schedule); - /* * preemption doesn't flush plug list, so it's possible ctx->cpu is * offline now @@ -1189,8 +1217,6 @@ static void blk_mq_insert_requests(struct request_queue *q, } blk_mq_hctx_mark_pending(hctx, ctx); spin_unlock(&ctx->lock); - - blk_mq_run_hw_queue(hctx, from_schedule); } static int plug_ctx_cmp(void *priv, struct list_head *a, struct list_head *b) @@ -1226,9 +1252,10 @@ void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) BUG_ON(!rq->q); if (rq->mq_ctx != this_ctx) { if (this_ctx) { - blk_mq_insert_requests(this_q, this_ctx, - &ctx_list, depth, - from_schedule); + trace_block_unplug(this_q, depth, from_schedule); + blk_mq_sched_insert_requests(this_q, this_ctx, + &ctx_list, + from_schedule); } this_ctx = rq->mq_ctx; @@ -1245,8 +1272,9 @@ void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) * on 'ctx_list'. Do those. */ if (this_ctx) { - blk_mq_insert_requests(this_q, this_ctx, &ctx_list, depth, - from_schedule); + trace_block_unplug(this_q, depth, from_schedule); + blk_mq_sched_insert_requests(this_q, this_ctx, &ctx_list, + from_schedule); } } @@ -1284,51 +1312,39 @@ insert_rq: } spin_unlock(&ctx->lock); - __blk_mq_free_request(hctx, ctx, rq); + __blk_mq_finish_request(hctx, ctx, rq); return true; } } -static struct request *blk_mq_map_request(struct request_queue *q, - struct bio *bio, - struct blk_mq_alloc_data *data) -{ - struct blk_mq_hw_ctx *hctx; - struct blk_mq_ctx *ctx; - struct request *rq; - - blk_queue_enter_live(q); - ctx = blk_mq_get_ctx(q); - hctx = blk_mq_map_queue(q, ctx->cpu); - - trace_block_getrq(q, bio, bio->bi_opf); - blk_mq_set_alloc_data(data, q, 0, ctx, hctx); - rq = __blk_mq_alloc_request(data, bio->bi_opf); - - data->hctx->queued++; - return rq; -} - static blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx, struct request *rq) { - return blk_tag_to_qc_t(rq->tag, hctx->queue_num, false); + if (rq->tag != -1) + return blk_tag_to_qc_t(rq->tag, hctx->queue_num, false); + + return blk_tag_to_qc_t(rq->internal_tag, hctx->queue_num, true); } static void blk_mq_try_issue_directly(struct request *rq, blk_qc_t *cookie) { - int ret; struct request_queue *q = rq->q; - struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, rq->mq_ctx->cpu); struct blk_mq_queue_data bd = { .rq = rq, .list = NULL, .last = 1 }; - blk_qc_t new_cookie = request_to_qc_t(hctx, rq); + struct blk_mq_hw_ctx *hctx; + blk_qc_t new_cookie; + int ret; - if (blk_mq_hctx_stopped(hctx)) + if (q->elevator) goto insert; + if (!blk_mq_get_driver_tag(rq, &hctx, false)) + goto insert; + + new_cookie = request_to_qc_t(hctx, rq); + /* * For OK queue, we are done. For error, kill it. Any other * error (busy), just add it to our list as we previously @@ -1350,7 +1366,7 @@ static void blk_mq_try_issue_directly(struct request *rq, blk_qc_t *cookie) } insert: - blk_mq_insert_request(rq, false, true, true); + blk_mq_sched_insert_request(rq, false, true, true); } /* @@ -1383,9 +1399,14 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) blk_attempt_plug_merge(q, bio, &request_count, &same_queue_rq)) return BLK_QC_T_NONE; + if (blk_mq_sched_bio_merge(q, bio)) + return BLK_QC_T_NONE; + wb_acct = wbt_wait(q->rq_wb, bio, NULL); - rq = blk_mq_map_request(q, bio, &data); + trace_block_getrq(q, bio, bio->bi_opf); + + rq = blk_mq_sched_get_request(q, bio, bio->bi_opf, &data); if (unlikely(!rq)) { __wbt_done(q->rq_wb, wb_acct); return BLK_QC_T_NONE; @@ -1397,6 +1418,7 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) if (unlikely(is_flush_fua)) { blk_mq_bio_to_request(rq, bio); + blk_mq_get_driver_tag(rq, NULL, true); blk_insert_flush(rq); goto run_queue; } @@ -1447,6 +1469,12 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) goto done; } + if (q->elevator) { + blk_mq_put_ctx(data.ctx); + blk_mq_bio_to_request(rq, bio); + blk_mq_sched_insert_request(rq, false, true, true); + goto done; + } if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) { /* * For a SYNC request, send it to the hardware immediately. For @@ -1492,9 +1520,14 @@ static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio) } else request_count = blk_plug_queued_count(q); + if (blk_mq_sched_bio_merge(q, bio)) + return BLK_QC_T_NONE; + wb_acct = wbt_wait(q->rq_wb, bio, NULL); - rq = blk_mq_map_request(q, bio, &data); + trace_block_getrq(q, bio, bio->bi_opf); + + rq = blk_mq_sched_get_request(q, bio, bio->bi_opf, &data); if (unlikely(!rq)) { __wbt_done(q->rq_wb, wb_acct); return BLK_QC_T_NONE; @@ -1506,6 +1539,7 @@ static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio) if (unlikely(is_flush_fua)) { blk_mq_bio_to_request(rq, bio); + blk_mq_get_driver_tag(rq, NULL, true); blk_insert_flush(rq); goto run_queue; } @@ -1544,6 +1578,12 @@ static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio) return cookie; } + if (q->elevator) { + blk_mq_put_ctx(data.ctx); + blk_mq_bio_to_request(rq, bio); + blk_mq_sched_insert_request(rq, false, true, true); + goto done; + } if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) { /* * For a SYNC request, send it to the hardware immediately. For @@ -1556,6 +1596,7 @@ run_queue: } blk_mq_put_ctx(data.ctx); +done: return cookie; } @@ -1925,9 +1966,11 @@ static bool __blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, int hctx_idx) static void blk_mq_free_map_and_requests(struct blk_mq_tag_set *set, unsigned int hctx_idx) { - blk_mq_free_rqs(set, set->tags[hctx_idx], hctx_idx); - blk_mq_free_rq_map(set->tags[hctx_idx]); - set->tags[hctx_idx] = NULL; + if (set->tags[hctx_idx]) { + blk_mq_free_rqs(set, set->tags[hctx_idx], hctx_idx); + blk_mq_free_rq_map(set->tags[hctx_idx]); + set->tags[hctx_idx] = NULL; + } } static void blk_mq_map_swqueue(struct request_queue *q, @@ -2084,6 +2127,8 @@ void blk_mq_release(struct request_queue *q) struct blk_mq_hw_ctx *hctx; unsigned int i; + blk_mq_sched_teardown(q); + /* hctx kobj stays in hctx */ queue_for_each_hw_ctx(q, hctx, i) { if (!hctx) @@ -2504,14 +2549,22 @@ int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr) struct blk_mq_hw_ctx *hctx; int i, ret; - if (!set || nr > set->queue_depth) + if (!set) return -EINVAL; ret = 0; queue_for_each_hw_ctx(q, hctx, i) { if (!hctx->tags) continue; - ret = blk_mq_tag_update_depth(hctx->tags, nr); + /* + * If we're using an MQ scheduler, just update the scheduler + * queue depth. This is similar to what the old code would do. + */ + if (!hctx->sched_tags) + ret = blk_mq_tag_update_depth(hctx->tags, + min(nr, set->queue_depth)); + else + ret = blk_mq_tag_update_depth(hctx->sched_tags, nr); if (ret) break; } @@ -2704,7 +2757,10 @@ bool blk_mq_poll(struct request_queue *q, blk_qc_t cookie) blk_flush_plug_list(plug, false); hctx = q->queue_hw_ctx[blk_qc_t_to_queue_num(cookie)]; - rq = blk_mq_tag_to_rq(hctx->tags, blk_qc_t_to_tag(cookie)); + if (!blk_qc_t_is_internal(cookie)) + rq = blk_mq_tag_to_rq(hctx->tags, blk_qc_t_to_tag(cookie)); + else + rq = blk_mq_tag_to_rq(hctx->sched_tags, blk_qc_t_to_tag(cookie)); return __blk_mq_poll(hctx, rq); } diff --git a/block/blk-mq.h b/block/blk-mq.h index 1b279b02d0f6..0c7c034d9ddd 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -52,6 +52,8 @@ int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, */ void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, bool at_head); +void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, + struct list_head *list); /* * CPU hotplug helpers */ @@ -124,6 +126,9 @@ static inline void blk_mq_set_alloc_data(struct blk_mq_alloc_data *data, static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data) { + if (data->flags & BLK_MQ_REQ_INTERNAL) + return data->hctx->sched_tags; + return data->hctx->tags; } @@ -132,8 +137,9 @@ static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data */ void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx, struct request *rq, unsigned int op); -void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, +void __blk_mq_finish_request(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, struct request *rq); +void blk_mq_finish_request(struct request *rq); struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data, unsigned int op); diff --git a/block/blk-tag.c b/block/blk-tag.c index bae1decb6ec3..07cc329fa4b0 100644 --- a/block/blk-tag.c +++ b/block/blk-tag.c @@ -272,6 +272,7 @@ void blk_queue_end_tag(struct request_queue *q, struct request *rq) list_del_init(&rq->queuelist); rq->rq_flags &= ~RQF_QUEUED; rq->tag = -1; + rq->internal_tag = -1; if (unlikely(bqt->tag_index[tag] == NULL)) printk(KERN_ERR "%s: tag %d is missing\n", diff --git a/block/elevator.c b/block/elevator.c index 022a26830297..0e1ccddab8a2 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -40,6 +40,7 @@ #include #include "blk.h" +#include "blk-mq-sched.h" static DEFINE_SPINLOCK(elv_list_lock); static LIST_HEAD(elv_list); @@ -58,7 +59,9 @@ static int elv_iosched_allow_bio_merge(struct request *rq, struct bio *bio) struct request_queue *q = rq->q; struct elevator_queue *e = q->elevator; - if (e->type->ops.sq.elevator_allow_bio_merge_fn) + if (e->uses_mq && e->type->ops.mq.allow_merge) + return e->type->ops.mq.allow_merge(q, rq, bio); + else if (!e->uses_mq && e->type->ops.sq.elevator_allow_bio_merge_fn) return e->type->ops.sq.elevator_allow_bio_merge_fn(q, rq, bio); return 1; @@ -163,6 +166,7 @@ struct elevator_queue *elevator_alloc(struct request_queue *q, kobject_init(&eq->kobj, &elv_ktype); mutex_init(&eq->sysfs_lock); hash_init(eq->hash); + eq->uses_mq = e->uses_mq; return eq; } @@ -219,14 +223,26 @@ int elevator_init(struct request_queue *q, char *name) if (!e) { printk(KERN_ERR "Default I/O scheduler not found. " \ - "Using noop.\n"); + "Using noop/none.\n"); + if (q->mq_ops) { + elevator_put(e); + return 0; + } e = elevator_get("noop", false); } } - err = e->ops.sq.elevator_init_fn(q, e); - if (err) + if (e->uses_mq) { + err = blk_mq_sched_setup(q); + if (!err) + err = e->ops.mq.init_sched(q, e); + } else + err = e->ops.sq.elevator_init_fn(q, e); + if (err) { + if (e->uses_mq) + blk_mq_sched_teardown(q); elevator_put(e); + } return err; } EXPORT_SYMBOL(elevator_init); @@ -234,7 +250,9 @@ EXPORT_SYMBOL(elevator_init); void elevator_exit(struct elevator_queue *e) { mutex_lock(&e->sysfs_lock); - if (e->type->ops.sq.elevator_exit_fn) + if (e->uses_mq && e->type->ops.mq.exit_sched) + e->type->ops.mq.exit_sched(e); + else if (!e->uses_mq && e->type->ops.sq.elevator_exit_fn) e->type->ops.sq.elevator_exit_fn(e); mutex_unlock(&e->sysfs_lock); @@ -253,6 +271,7 @@ void elv_rqhash_del(struct request_queue *q, struct request *rq) if (ELV_ON_HASH(rq)) __elv_rqhash_del(rq); } +EXPORT_SYMBOL_GPL(elv_rqhash_del); void elv_rqhash_add(struct request_queue *q, struct request *rq) { @@ -262,6 +281,7 @@ void elv_rqhash_add(struct request_queue *q, struct request *rq) hash_add(e->hash, &rq->hash, rq_hash_key(rq)); rq->rq_flags |= RQF_HASHED; } +EXPORT_SYMBOL_GPL(elv_rqhash_add); void elv_rqhash_reposition(struct request_queue *q, struct request *rq) { @@ -443,7 +463,9 @@ int elv_merge(struct request_queue *q, struct request **req, struct bio *bio) return ELEVATOR_BACK_MERGE; } - if (e->type->ops.sq.elevator_merge_fn) + if (e->uses_mq && e->type->ops.mq.request_merge) + return e->type->ops.mq.request_merge(q, req, bio); + else if (!e->uses_mq && e->type->ops.sq.elevator_merge_fn) return e->type->ops.sq.elevator_merge_fn(q, req, bio); return ELEVATOR_NO_MERGE; @@ -456,8 +478,7 @@ int elv_merge(struct request_queue *q, struct request **req, struct bio *bio) * * Returns true if we merged, false otherwise */ -static bool elv_attempt_insert_merge(struct request_queue *q, - struct request *rq) +bool elv_attempt_insert_merge(struct request_queue *q, struct request *rq) { struct request *__rq; bool ret; @@ -495,7 +516,9 @@ void elv_merged_request(struct request_queue *q, struct request *rq, int type) { struct elevator_queue *e = q->elevator; - if (e->type->ops.sq.elevator_merged_fn) + if (e->uses_mq && e->type->ops.mq.request_merged) + e->type->ops.mq.request_merged(q, rq, type); + else if (!e->uses_mq && e->type->ops.sq.elevator_merged_fn) e->type->ops.sq.elevator_merged_fn(q, rq, type); if (type == ELEVATOR_BACK_MERGE) @@ -508,10 +531,15 @@ void elv_merge_requests(struct request_queue *q, struct request *rq, struct request *next) { struct elevator_queue *e = q->elevator; - const int next_sorted = next->rq_flags & RQF_SORTED; + bool next_sorted = false; - if (next_sorted && e->type->ops.sq.elevator_merge_req_fn) - e->type->ops.sq.elevator_merge_req_fn(q, rq, next); + if (e->uses_mq && e->type->ops.mq.requests_merged) + e->type->ops.mq.requests_merged(q, rq, next); + else if (e->type->ops.sq.elevator_merge_req_fn) { + next_sorted = next->rq_flags & RQF_SORTED; + if (next_sorted) + e->type->ops.sq.elevator_merge_req_fn(q, rq, next); + } elv_rqhash_reposition(q, rq); @@ -528,6 +556,9 @@ void elv_bio_merged(struct request_queue *q, struct request *rq, { struct elevator_queue *e = q->elevator; + if (WARN_ON_ONCE(e->uses_mq)) + return; + if (e->type->ops.sq.elevator_bio_merged_fn) e->type->ops.sq.elevator_bio_merged_fn(q, rq, bio); } @@ -574,11 +605,15 @@ void elv_requeue_request(struct request_queue *q, struct request *rq) void elv_drain_elevator(struct request_queue *q) { + struct elevator_queue *e = q->elevator; static int printed; + if (WARN_ON_ONCE(e->uses_mq)) + return; + lockdep_assert_held(q->queue_lock); - while (q->elevator->type->ops.sq.elevator_dispatch_fn(q, 1)) + while (e->type->ops.sq.elevator_dispatch_fn(q, 1)) ; if (q->nr_sorted && printed++ < 10) { printk(KERN_ERR "%s: forced dispatching is broken " @@ -682,8 +717,11 @@ struct request *elv_latter_request(struct request_queue *q, struct request *rq) { struct elevator_queue *e = q->elevator; - if (e->type->ops.sq.elevator_latter_req_fn) + if (e->uses_mq && e->type->ops.mq.next_request) + return e->type->ops.mq.next_request(q, rq); + else if (!e->uses_mq && e->type->ops.sq.elevator_latter_req_fn) return e->type->ops.sq.elevator_latter_req_fn(q, rq); + return NULL; } @@ -691,7 +729,9 @@ struct request *elv_former_request(struct request_queue *q, struct request *rq) { struct elevator_queue *e = q->elevator; - if (e->type->ops.sq.elevator_former_req_fn) + if (e->uses_mq && e->type->ops.mq.former_request) + return e->type->ops.mq.former_request(q, rq); + if (!e->uses_mq && e->type->ops.sq.elevator_former_req_fn) return e->type->ops.sq.elevator_former_req_fn(q, rq); return NULL; } @@ -701,6 +741,9 @@ int elv_set_request(struct request_queue *q, struct request *rq, { struct elevator_queue *e = q->elevator; + if (WARN_ON_ONCE(e->uses_mq)) + return 0; + if (e->type->ops.sq.elevator_set_req_fn) return e->type->ops.sq.elevator_set_req_fn(q, rq, bio, gfp_mask); return 0; @@ -710,6 +753,9 @@ void elv_put_request(struct request_queue *q, struct request *rq) { struct elevator_queue *e = q->elevator; + if (WARN_ON_ONCE(e->uses_mq)) + return; + if (e->type->ops.sq.elevator_put_req_fn) e->type->ops.sq.elevator_put_req_fn(rq); } @@ -718,6 +764,9 @@ int elv_may_queue(struct request_queue *q, unsigned int op) { struct elevator_queue *e = q->elevator; + if (WARN_ON_ONCE(e->uses_mq)) + return 0; + if (e->type->ops.sq.elevator_may_queue_fn) return e->type->ops.sq.elevator_may_queue_fn(q, op); @@ -728,6 +777,9 @@ void elv_completed_request(struct request_queue *q, struct request *rq) { struct elevator_queue *e = q->elevator; + if (WARN_ON_ONCE(e->uses_mq)) + return; + /* * request is released from the driver, io must be done */ @@ -803,7 +855,7 @@ int elv_register_queue(struct request_queue *q) } kobject_uevent(&e->kobj, KOBJ_ADD); e->registered = 1; - if (e->type->ops.sq.elevator_registered_fn) + if (!e->uses_mq && e->type->ops.sq.elevator_registered_fn) e->type->ops.sq.elevator_registered_fn(q); } return error; @@ -891,9 +943,14 @@ EXPORT_SYMBOL_GPL(elv_unregister); static int elevator_switch(struct request_queue *q, struct elevator_type *new_e) { struct elevator_queue *old = q->elevator; - bool registered = old->registered; + bool old_registered = false; int err; + if (q->mq_ops) { + blk_mq_freeze_queue(q); + blk_mq_quiesce_queue(q); + } + /* * Turn on BYPASS and drain all requests w/ elevator private data. * Block layer doesn't call into a quiesced elevator - all requests @@ -901,42 +958,76 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e) * using INSERT_BACK. All requests have SOFTBARRIER set and no * merge happens either. */ - blk_queue_bypass_start(q); + if (old) { + old_registered = old->registered; - /* unregister and clear all auxiliary data of the old elevator */ - if (registered) - elv_unregister_queue(q); + if (old->uses_mq) + blk_mq_sched_teardown(q); - spin_lock_irq(q->queue_lock); - ioc_clear_queue(q); - spin_unlock_irq(q->queue_lock); + if (!q->mq_ops) + blk_queue_bypass_start(q); + + /* unregister and clear all auxiliary data of the old elevator */ + if (old_registered) + elv_unregister_queue(q); + + spin_lock_irq(q->queue_lock); + ioc_clear_queue(q); + spin_unlock_irq(q->queue_lock); + } /* allocate, init and register new elevator */ - err = new_e->ops.sq.elevator_init_fn(q, new_e); - if (err) - goto fail_init; + if (new_e) { + if (new_e->uses_mq) { + err = blk_mq_sched_setup(q); + if (!err) + err = new_e->ops.mq.init_sched(q, new_e); + } else + err = new_e->ops.sq.elevator_init_fn(q, new_e); + if (err) + goto fail_init; - if (registered) { err = elv_register_queue(q); if (err) goto fail_register; - } + } else + q->elevator = NULL; /* done, kill the old one and finish */ - elevator_exit(old); - blk_queue_bypass_end(q); + if (old) { + elevator_exit(old); + if (!q->mq_ops) + blk_queue_bypass_end(q); + } - blk_add_trace_msg(q, "elv switch: %s", new_e->elevator_name); + if (q->mq_ops) { + blk_mq_unfreeze_queue(q); + blk_mq_start_stopped_hw_queues(q, true); + } + + if (new_e) + blk_add_trace_msg(q, "elv switch: %s", new_e->elevator_name); + else + blk_add_trace_msg(q, "elv switch: none"); return 0; fail_register: + if (q->mq_ops) + blk_mq_sched_teardown(q); elevator_exit(q->elevator); fail_init: /* switch failed, restore and re-register old elevator */ - q->elevator = old; - elv_register_queue(q); - blk_queue_bypass_end(q); + if (old) { + q->elevator = old; + elv_register_queue(q); + if (!q->mq_ops) + blk_queue_bypass_end(q); + } + if (q->mq_ops) { + blk_mq_unfreeze_queue(q); + blk_mq_start_stopped_hw_queues(q, true); + } return err; } @@ -949,8 +1040,11 @@ static int __elevator_change(struct request_queue *q, const char *name) char elevator_name[ELV_NAME_MAX]; struct elevator_type *e; - if (!q->elevator) - return -ENXIO; + /* + * Special case for mq, turn off scheduling + */ + if (q->mq_ops && !strncmp(name, "none", 4)) + return elevator_switch(q, NULL); strlcpy(elevator_name, name, sizeof(elevator_name)); e = elevator_get(strstrip(elevator_name), true); @@ -959,11 +1053,21 @@ static int __elevator_change(struct request_queue *q, const char *name) return -EINVAL; } - if (!strcmp(elevator_name, q->elevator->type->elevator_name)) { + if (q->elevator && + !strcmp(elevator_name, q->elevator->type->elevator_name)) { elevator_put(e); return 0; } + if (!e->uses_mq && q->mq_ops) { + elevator_put(e); + return -EINVAL; + } + if (e->uses_mq && !q->mq_ops) { + elevator_put(e); + return -EINVAL; + } + return elevator_switch(q, e); } @@ -985,7 +1089,7 @@ ssize_t elv_iosched_store(struct request_queue *q, const char *name, { int ret; - if (!q->elevator) + if (!(q->mq_ops || q->request_fn)) return count; ret = __elevator_change(q, name); @@ -999,24 +1103,34 @@ ssize_t elv_iosched_store(struct request_queue *q, const char *name, ssize_t elv_iosched_show(struct request_queue *q, char *name) { struct elevator_queue *e = q->elevator; - struct elevator_type *elv; + struct elevator_type *elv = NULL; struct elevator_type *__e; int len = 0; - if (!q->elevator || !blk_queue_stackable(q)) + if (!blk_queue_stackable(q)) return sprintf(name, "none\n"); - elv = e->type; + if (!q->elevator) + len += sprintf(name+len, "[none] "); + else + elv = e->type; spin_lock(&elv_list_lock); list_for_each_entry(__e, &elv_list, list) { - if (!strcmp(elv->elevator_name, __e->elevator_name)) + if (elv && !strcmp(elv->elevator_name, __e->elevator_name)) { len += sprintf(name+len, "[%s] ", elv->elevator_name); - else + continue; + } + if (__e->uses_mq && q->mq_ops) + len += sprintf(name+len, "%s ", __e->elevator_name); + else if (!__e->uses_mq && !q->mq_ops) len += sprintf(name+len, "%s ", __e->elevator_name); } spin_unlock(&elv_list_lock); + if (q->mq_ops && q->elevator) + len += sprintf(name+len, "none"); + len += sprintf(len+name, "\n"); return len; } diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 2686f9e7302a..63569eb46d15 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -22,6 +22,7 @@ struct blk_mq_hw_ctx { unsigned long flags; /* BLK_MQ_F_* flags */ + void *sched_data; struct request_queue *queue; struct blk_flush_queue *fq; @@ -35,6 +36,7 @@ struct blk_mq_hw_ctx { atomic_t wait_index; struct blk_mq_tags *tags; + struct blk_mq_tags *sched_tags; struct srcu_struct queue_rq_srcu; @@ -156,6 +158,7 @@ enum { BLK_MQ_S_STOPPED = 0, BLK_MQ_S_TAG_ACTIVE = 1, + BLK_MQ_S_SCHED_RESTART = 2, BLK_MQ_MAX_DEPTH = 10240, @@ -179,13 +182,13 @@ void blk_mq_free_tag_set(struct blk_mq_tag_set *set); void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule); -void blk_mq_insert_request(struct request *, bool, bool, bool); void blk_mq_free_request(struct request *rq); bool blk_mq_can_queue(struct blk_mq_hw_ctx *); enum { BLK_MQ_REQ_NOWAIT = (1 << 0), /* return when out of requests */ BLK_MQ_REQ_RESERVED = (1 << 1), /* allocate from reserved pool */ + BLK_MQ_REQ_INTERNAL = (1 << 2), /* allocate internal/sched tag */ }; struct request *blk_mq_alloc_request(struct request_queue *q, int rw, diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 2e99d659b0f1..25564857f5f8 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -154,6 +154,7 @@ struct request { /* the following two fields are internal, NEVER access directly */ unsigned int __data_len; /* total data len */ + int tag; sector_t __sector; /* sector cursor */ struct bio *bio; @@ -220,9 +221,10 @@ struct request { unsigned short ioprio; + int internal_tag; + void *special; /* opaque pointer available for LLD use */ - int tag; int errors; /* diff --git a/include/linux/elevator.h b/include/linux/elevator.h index 2a9e966eed03..ecb96fd67c6d 100644 --- a/include/linux/elevator.h +++ b/include/linux/elevator.h @@ -77,6 +77,34 @@ struct elevator_ops elevator_registered_fn *elevator_registered_fn; }; +struct blk_mq_alloc_data; +struct blk_mq_hw_ctx; + +struct elevator_mq_ops { + int (*init_sched)(struct request_queue *, struct elevator_type *); + void (*exit_sched)(struct elevator_queue *); + + bool (*allow_merge)(struct request_queue *, struct request *, struct bio *); + bool (*bio_merge)(struct blk_mq_hw_ctx *, struct bio *); + int (*request_merge)(struct request_queue *q, struct request **, struct bio *); + void (*request_merged)(struct request_queue *, struct request *, int); + void (*requests_merged)(struct request_queue *, struct request *, struct request *); + struct request *(*get_request)(struct request_queue *, unsigned int, struct blk_mq_alloc_data *); + void (*put_request)(struct request *); + void (*insert_requests)(struct blk_mq_hw_ctx *, struct list_head *, bool); + void (*dispatch_requests)(struct blk_mq_hw_ctx *, struct list_head *); + bool (*has_work)(struct blk_mq_hw_ctx *); + void (*completed_request)(struct blk_mq_hw_ctx *, struct request *); + void (*started_request)(struct request *); + void (*requeue_request)(struct request *); + struct request *(*former_request)(struct request_queue *, struct request *); + struct request *(*next_request)(struct request_queue *, struct request *); + int (*get_rq_priv)(struct request_queue *, struct request *); + void (*put_rq_priv)(struct request_queue *, struct request *); + void (*init_icq)(struct io_cq *); + void (*exit_icq)(struct io_cq *); +}; + #define ELV_NAME_MAX (16) struct elv_fs_entry { @@ -96,12 +124,14 @@ struct elevator_type /* fields provided by elevator implementation */ union { struct elevator_ops sq; + struct elevator_mq_ops mq; } ops; size_t icq_size; /* see iocontext.h */ size_t icq_align; /* ditto */ struct elv_fs_entry *elevator_attrs; char elevator_name[ELV_NAME_MAX]; struct module *elevator_owner; + bool uses_mq; /* managed by elevator core */ char icq_cache_name[ELV_NAME_MAX + 5]; /* elvname + "_io_cq" */ @@ -125,6 +155,7 @@ struct elevator_queue struct kobject kobj; struct mutex sysfs_lock; unsigned int registered:1; + unsigned int uses_mq:1; DECLARE_HASHTABLE(hash, ELV_HASH_BITS); }; @@ -141,6 +172,7 @@ extern void elv_merge_requests(struct request_queue *, struct request *, extern void elv_merged_request(struct request_queue *, struct request *, int); extern void elv_bio_merged(struct request_queue *q, struct request *, struct bio *); +extern bool elv_attempt_insert_merge(struct request_queue *, struct request *); extern void elv_requeue_request(struct request_queue *, struct request *); extern struct request *elv_former_request(struct request_queue *, struct request *); extern struct request *elv_latter_request(struct request_queue *, struct request *); From 945ffb60c11dfb228130f3f2bdde961cecb76671 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Sat, 14 Jan 2017 17:11:11 -0700 Subject: [PATCH 15/49] mq-deadline: add blk-mq adaptation of the deadline IO scheduler This is basically identical to deadline-iosched, except it registers as a MQ capable scheduler. This is still a single queue design. Signed-off-by: Jens Axboe Reviewed-by: Bart Van Assche Reviewed-by: Omar Sandoval --- block/Kconfig.iosched | 6 + block/Makefile | 1 + block/mq-deadline.c | 553 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 560 insertions(+) create mode 100644 block/mq-deadline.c diff --git a/block/Kconfig.iosched b/block/Kconfig.iosched index 421bef9c4c48..490ef2850fae 100644 --- a/block/Kconfig.iosched +++ b/block/Kconfig.iosched @@ -32,6 +32,12 @@ config IOSCHED_CFQ This is the default I/O scheduler. +config MQ_IOSCHED_DEADLINE + tristate "MQ deadline I/O scheduler" + default y + ---help--- + MQ version of the deadline IO scheduler. + config CFQ_GROUP_IOSCHED bool "CFQ Group Scheduling support" depends on IOSCHED_CFQ && BLK_CGROUP diff --git a/block/Makefile b/block/Makefile index 2eee9e1bb6db..3ee0abd7205a 100644 --- a/block/Makefile +++ b/block/Makefile @@ -18,6 +18,7 @@ obj-$(CONFIG_BLK_DEV_THROTTLING) += blk-throttle.o obj-$(CONFIG_IOSCHED_NOOP) += noop-iosched.o obj-$(CONFIG_IOSCHED_DEADLINE) += deadline-iosched.o obj-$(CONFIG_IOSCHED_CFQ) += cfq-iosched.o +obj-$(CONFIG_MQ_IOSCHED_DEADLINE) += mq-deadline.o obj-$(CONFIG_BLOCK_COMPAT) += compat_ioctl.o obj-$(CONFIG_BLK_CMDLINE_PARSER) += cmdline-parser.o diff --git a/block/mq-deadline.c b/block/mq-deadline.c new file mode 100644 index 000000000000..a01986d7b6fb --- /dev/null +++ b/block/mq-deadline.c @@ -0,0 +1,553 @@ +/* + * MQ Deadline i/o scheduler - adaptation of the legacy deadline scheduler, + * for the blk-mq scheduling framework + * + * Copyright (C) 2016 Jens Axboe + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "blk.h" +#include "blk-mq.h" +#include "blk-mq-tag.h" +#include "blk-mq-sched.h" + +/* + * See Documentation/block/deadline-iosched.txt + */ +static const int read_expire = HZ / 2; /* max time before a read is submitted. */ +static const int write_expire = 5 * HZ; /* ditto for writes, these limits are SOFT! */ +static const int writes_starved = 2; /* max times reads can starve a write */ +static const int fifo_batch = 16; /* # of sequential requests treated as one + by the above parameters. For throughput. */ + +struct deadline_data { + /* + * run time data + */ + + /* + * requests (deadline_rq s) are present on both sort_list and fifo_list + */ + struct rb_root sort_list[2]; + struct list_head fifo_list[2]; + + /* + * next in sort order. read, write or both are NULL + */ + struct request *next_rq[2]; + unsigned int batching; /* number of sequential requests made */ + unsigned int starved; /* times reads have starved writes */ + + /* + * settings that change how the i/o scheduler behaves + */ + int fifo_expire[2]; + int fifo_batch; + int writes_starved; + int front_merges; + + spinlock_t lock; + struct list_head dispatch; +}; + +static inline struct rb_root * +deadline_rb_root(struct deadline_data *dd, struct request *rq) +{ + return &dd->sort_list[rq_data_dir(rq)]; +} + +/* + * get the request after `rq' in sector-sorted order + */ +static inline struct request * +deadline_latter_request(struct request *rq) +{ + struct rb_node *node = rb_next(&rq->rb_node); + + if (node) + return rb_entry_rq(node); + + return NULL; +} + +static void +deadline_add_rq_rb(struct deadline_data *dd, struct request *rq) +{ + struct rb_root *root = deadline_rb_root(dd, rq); + + elv_rb_add(root, rq); +} + +static inline void +deadline_del_rq_rb(struct deadline_data *dd, struct request *rq) +{ + const int data_dir = rq_data_dir(rq); + + if (dd->next_rq[data_dir] == rq) + dd->next_rq[data_dir] = deadline_latter_request(rq); + + elv_rb_del(deadline_rb_root(dd, rq), rq); +} + +/* + * remove rq from rbtree and fifo. + */ +static void deadline_remove_request(struct request_queue *q, struct request *rq) +{ + struct deadline_data *dd = q->elevator->elevator_data; + + list_del_init(&rq->queuelist); + + /* + * We might not be on the rbtree, if we are doing an insert merge + */ + if (!RB_EMPTY_NODE(&rq->rb_node)) + deadline_del_rq_rb(dd, rq); + + elv_rqhash_del(q, rq); + if (q->last_merge == rq) + q->last_merge = NULL; +} + +static void dd_request_merged(struct request_queue *q, struct request *req, + int type) +{ + struct deadline_data *dd = q->elevator->elevator_data; + + /* + * if the merge was a front merge, we need to reposition request + */ + if (type == ELEVATOR_FRONT_MERGE) { + elv_rb_del(deadline_rb_root(dd, req), req); + deadline_add_rq_rb(dd, req); + } +} + +static void dd_merged_requests(struct request_queue *q, struct request *req, + struct request *next) +{ + /* + * if next expires before rq, assign its expire time to rq + * and move into next position (next will be deleted) in fifo + */ + if (!list_empty(&req->queuelist) && !list_empty(&next->queuelist)) { + if (time_before((unsigned long)next->fifo_time, + (unsigned long)req->fifo_time)) { + list_move(&req->queuelist, &next->queuelist); + req->fifo_time = next->fifo_time; + } + } + + /* + * kill knowledge of next, this one is a goner + */ + deadline_remove_request(q, next); +} + +/* + * move an entry to dispatch queue + */ +static void +deadline_move_request(struct deadline_data *dd, struct request *rq) +{ + const int data_dir = rq_data_dir(rq); + + dd->next_rq[READ] = NULL; + dd->next_rq[WRITE] = NULL; + dd->next_rq[data_dir] = deadline_latter_request(rq); + + /* + * take it off the sort and fifo list + */ + deadline_remove_request(rq->q, rq); +} + +/* + * deadline_check_fifo returns 0 if there are no expired requests on the fifo, + * 1 otherwise. Requires !list_empty(&dd->fifo_list[data_dir]) + */ +static inline int deadline_check_fifo(struct deadline_data *dd, int ddir) +{ + struct request *rq = rq_entry_fifo(dd->fifo_list[ddir].next); + + /* + * rq is expired! + */ + if (time_after_eq(jiffies, (unsigned long)rq->fifo_time)) + return 1; + + return 0; +} + +/* + * deadline_dispatch_requests selects the best request according to + * read/write expire, fifo_batch, etc + */ +static struct request *__dd_dispatch_request(struct blk_mq_hw_ctx *hctx) +{ + struct deadline_data *dd = hctx->queue->elevator->elevator_data; + struct request *rq; + bool reads, writes; + int data_dir; + + if (!list_empty(&dd->dispatch)) { + rq = list_first_entry(&dd->dispatch, struct request, queuelist); + list_del_init(&rq->queuelist); + goto done; + } + + reads = !list_empty(&dd->fifo_list[READ]); + writes = !list_empty(&dd->fifo_list[WRITE]); + + /* + * batches are currently reads XOR writes + */ + if (dd->next_rq[WRITE]) + rq = dd->next_rq[WRITE]; + else + rq = dd->next_rq[READ]; + + if (rq && dd->batching < dd->fifo_batch) + /* we have a next request are still entitled to batch */ + goto dispatch_request; + + /* + * at this point we are not running a batch. select the appropriate + * data direction (read / write) + */ + + if (reads) { + BUG_ON(RB_EMPTY_ROOT(&dd->sort_list[READ])); + + if (writes && (dd->starved++ >= dd->writes_starved)) + goto dispatch_writes; + + data_dir = READ; + + goto dispatch_find_request; + } + + /* + * there are either no reads or writes have been starved + */ + + if (writes) { +dispatch_writes: + BUG_ON(RB_EMPTY_ROOT(&dd->sort_list[WRITE])); + + dd->starved = 0; + + data_dir = WRITE; + + goto dispatch_find_request; + } + + return NULL; + +dispatch_find_request: + /* + * we are not running a batch, find best request for selected data_dir + */ + if (deadline_check_fifo(dd, data_dir) || !dd->next_rq[data_dir]) { + /* + * A deadline has expired, the last request was in the other + * direction, or we have run out of higher-sectored requests. + * Start again from the request with the earliest expiry time. + */ + rq = rq_entry_fifo(dd->fifo_list[data_dir].next); + } else { + /* + * The last req was the same dir and we have a next request in + * sort order. No expired requests so continue on from here. + */ + rq = dd->next_rq[data_dir]; + } + + dd->batching = 0; + +dispatch_request: + /* + * rq is the selected appropriate request. + */ + dd->batching++; + deadline_move_request(dd, rq); +done: + rq->rq_flags |= RQF_STARTED; + return rq; +} + +static void dd_dispatch_requests(struct blk_mq_hw_ctx *hctx, + struct list_head *rq_list) +{ + struct deadline_data *dd = hctx->queue->elevator->elevator_data; + + spin_lock(&dd->lock); + blk_mq_sched_move_to_dispatch(hctx, rq_list, __dd_dispatch_request); + spin_unlock(&dd->lock); +} + +static void dd_exit_queue(struct elevator_queue *e) +{ + struct deadline_data *dd = e->elevator_data; + + BUG_ON(!list_empty(&dd->fifo_list[READ])); + BUG_ON(!list_empty(&dd->fifo_list[WRITE])); + + kfree(dd); +} + +/* + * initialize elevator private data (deadline_data). + */ +static int dd_init_queue(struct request_queue *q, struct elevator_type *e) +{ + struct deadline_data *dd; + struct elevator_queue *eq; + + eq = elevator_alloc(q, e); + if (!eq) + return -ENOMEM; + + dd = kzalloc_node(sizeof(*dd), GFP_KERNEL, q->node); + if (!dd) { + kobject_put(&eq->kobj); + return -ENOMEM; + } + eq->elevator_data = dd; + + INIT_LIST_HEAD(&dd->fifo_list[READ]); + INIT_LIST_HEAD(&dd->fifo_list[WRITE]); + dd->sort_list[READ] = RB_ROOT; + dd->sort_list[WRITE] = RB_ROOT; + dd->fifo_expire[READ] = read_expire; + dd->fifo_expire[WRITE] = write_expire; + dd->writes_starved = writes_starved; + dd->front_merges = 1; + dd->fifo_batch = fifo_batch; + spin_lock_init(&dd->lock); + INIT_LIST_HEAD(&dd->dispatch); + + q->elevator = eq; + return 0; +} + +static int dd_request_merge(struct request_queue *q, struct request **rq, + struct bio *bio) +{ + struct deadline_data *dd = q->elevator->elevator_data; + sector_t sector = bio_end_sector(bio); + struct request *__rq; + + if (!dd->front_merges) + return ELEVATOR_NO_MERGE; + + __rq = elv_rb_find(&dd->sort_list[bio_data_dir(bio)], sector); + if (__rq) { + BUG_ON(sector != blk_rq_pos(__rq)); + + if (elv_bio_merge_ok(__rq, bio)) { + *rq = __rq; + return ELEVATOR_FRONT_MERGE; + } + } + + return ELEVATOR_NO_MERGE; +} + +static bool dd_bio_merge(struct blk_mq_hw_ctx *hctx, struct bio *bio) +{ + struct request_queue *q = hctx->queue; + struct deadline_data *dd = q->elevator->elevator_data; + int ret; + + spin_lock(&dd->lock); + ret = blk_mq_sched_try_merge(q, bio); + spin_unlock(&dd->lock); + + return ret; +} + +/* + * add rq to rbtree and fifo + */ +static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, + bool at_head) +{ + struct request_queue *q = hctx->queue; + struct deadline_data *dd = q->elevator->elevator_data; + const int data_dir = rq_data_dir(rq); + + if (blk_mq_sched_try_insert_merge(q, rq)) + return; + + blk_mq_sched_request_inserted(rq); + + if (blk_mq_sched_bypass_insert(hctx, rq)) + return; + + if (at_head || rq->cmd_type != REQ_TYPE_FS) { + if (at_head) + list_add(&rq->queuelist, &dd->dispatch); + else + list_add_tail(&rq->queuelist, &dd->dispatch); + } else { + deadline_add_rq_rb(dd, rq); + + if (rq_mergeable(rq)) { + elv_rqhash_add(q, rq); + if (!q->last_merge) + q->last_merge = rq; + } + + /* + * set expire time and add to fifo list + */ + rq->fifo_time = jiffies + dd->fifo_expire[data_dir]; + list_add_tail(&rq->queuelist, &dd->fifo_list[data_dir]); + } +} + +static void dd_insert_requests(struct blk_mq_hw_ctx *hctx, + struct list_head *list, bool at_head) +{ + struct request_queue *q = hctx->queue; + struct deadline_data *dd = q->elevator->elevator_data; + + spin_lock(&dd->lock); + while (!list_empty(list)) { + struct request *rq; + + rq = list_first_entry(list, struct request, queuelist); + list_del_init(&rq->queuelist); + dd_insert_request(hctx, rq, at_head); + } + spin_unlock(&dd->lock); +} + +static bool dd_has_work(struct blk_mq_hw_ctx *hctx) +{ + struct deadline_data *dd = hctx->queue->elevator->elevator_data; + + return !list_empty_careful(&dd->dispatch) || + !list_empty_careful(&dd->fifo_list[0]) || + !list_empty_careful(&dd->fifo_list[1]); +} + +/* + * sysfs parts below + */ +static ssize_t +deadline_var_show(int var, char *page) +{ + return sprintf(page, "%d\n", var); +} + +static ssize_t +deadline_var_store(int *var, const char *page, size_t count) +{ + char *p = (char *) page; + + *var = simple_strtol(p, &p, 10); + return count; +} + +#define SHOW_FUNCTION(__FUNC, __VAR, __CONV) \ +static ssize_t __FUNC(struct elevator_queue *e, char *page) \ +{ \ + struct deadline_data *dd = e->elevator_data; \ + int __data = __VAR; \ + if (__CONV) \ + __data = jiffies_to_msecs(__data); \ + return deadline_var_show(__data, (page)); \ +} +SHOW_FUNCTION(deadline_read_expire_show, dd->fifo_expire[READ], 1); +SHOW_FUNCTION(deadline_write_expire_show, dd->fifo_expire[WRITE], 1); +SHOW_FUNCTION(deadline_writes_starved_show, dd->writes_starved, 0); +SHOW_FUNCTION(deadline_front_merges_show, dd->front_merges, 0); +SHOW_FUNCTION(deadline_fifo_batch_show, dd->fifo_batch, 0); +#undef SHOW_FUNCTION + +#define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \ +static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count) \ +{ \ + struct deadline_data *dd = e->elevator_data; \ + int __data; \ + int ret = deadline_var_store(&__data, (page), count); \ + if (__data < (MIN)) \ + __data = (MIN); \ + else if (__data > (MAX)) \ + __data = (MAX); \ + if (__CONV) \ + *(__PTR) = msecs_to_jiffies(__data); \ + else \ + *(__PTR) = __data; \ + return ret; \ +} +STORE_FUNCTION(deadline_read_expire_store, &dd->fifo_expire[READ], 0, INT_MAX, 1); +STORE_FUNCTION(deadline_write_expire_store, &dd->fifo_expire[WRITE], 0, INT_MAX, 1); +STORE_FUNCTION(deadline_writes_starved_store, &dd->writes_starved, INT_MIN, INT_MAX, 0); +STORE_FUNCTION(deadline_front_merges_store, &dd->front_merges, 0, 1, 0); +STORE_FUNCTION(deadline_fifo_batch_store, &dd->fifo_batch, 0, INT_MAX, 0); +#undef STORE_FUNCTION + +#define DD_ATTR(name) \ + __ATTR(name, S_IRUGO|S_IWUSR, deadline_##name##_show, \ + deadline_##name##_store) + +static struct elv_fs_entry deadline_attrs[] = { + DD_ATTR(read_expire), + DD_ATTR(write_expire), + DD_ATTR(writes_starved), + DD_ATTR(front_merges), + DD_ATTR(fifo_batch), + __ATTR_NULL +}; + +static struct elevator_type mq_deadline = { + .ops.mq = { + .insert_requests = dd_insert_requests, + .dispatch_requests = dd_dispatch_requests, + .next_request = elv_rb_latter_request, + .former_request = elv_rb_former_request, + .bio_merge = dd_bio_merge, + .request_merge = dd_request_merge, + .requests_merged = dd_merged_requests, + .request_merged = dd_request_merged, + .has_work = dd_has_work, + .init_sched = dd_init_queue, + .exit_sched = dd_exit_queue, + }, + + .uses_mq = true, + .elevator_attrs = deadline_attrs, + .elevator_name = "mq-deadline", + .elevator_owner = THIS_MODULE, +}; + +static int __init deadline_init(void) +{ + return elv_register(&mq_deadline); +} + +static void __exit deadline_exit(void) +{ + elv_unregister(&mq_deadline); +} + +module_init(deadline_init); +module_exit(deadline_exit); + +MODULE_AUTHOR("Jens Axboe"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("MQ deadline IO scheduler"); From d34849913819a5e0cbfbe724dbe79df89278c524 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Fri, 13 Jan 2017 14:43:58 -0700 Subject: [PATCH 16/49] blk-mq-sched: allow setting of default IO scheduler Add Kconfig entries to manage what devices get assigned an MQ scheduler, and add a blk-mq flag for drivers to opt out of scheduling. The latter is useful for admin type queues that still allocate a blk-mq queue and tag set, but aren't use for normal IO. Signed-off-by: Jens Axboe Reviewed-by: Bart Van Assche Reviewed-by: Omar Sandoval --- block/Kconfig.iosched | 56 ++++++++++++++++++++++++++++++++++++----- block/blk-mq-sched.c | 20 +++++++++++++++ block/blk-mq-sched.h | 2 ++ block/blk-mq.c | 8 ++++++ block/elevator.c | 8 +++++- drivers/nvme/host/pci.c | 1 + include/linux/blk-mq.h | 1 + 7 files changed, 89 insertions(+), 7 deletions(-) diff --git a/block/Kconfig.iosched b/block/Kconfig.iosched index 490ef2850fae..0715ce93daef 100644 --- a/block/Kconfig.iosched +++ b/block/Kconfig.iosched @@ -32,12 +32,6 @@ config IOSCHED_CFQ This is the default I/O scheduler. -config MQ_IOSCHED_DEADLINE - tristate "MQ deadline I/O scheduler" - default y - ---help--- - MQ version of the deadline IO scheduler. - config CFQ_GROUP_IOSCHED bool "CFQ Group Scheduling support" depends on IOSCHED_CFQ && BLK_CGROUP @@ -69,6 +63,56 @@ config DEFAULT_IOSCHED default "cfq" if DEFAULT_CFQ default "noop" if DEFAULT_NOOP +config MQ_IOSCHED_DEADLINE + tristate "MQ deadline I/O scheduler" + default y + ---help--- + MQ version of the deadline IO scheduler. + +config MQ_IOSCHED_NONE + bool + default y + +choice + prompt "Default single-queue blk-mq I/O scheduler" + default DEFAULT_SQ_NONE + help + Select the I/O scheduler which will be used by default for blk-mq + managed block devices with a single queue. + + config DEFAULT_SQ_DEADLINE + bool "MQ Deadline" if MQ_IOSCHED_DEADLINE=y + + config DEFAULT_SQ_NONE + bool "None" + +endchoice + +config DEFAULT_SQ_IOSCHED + string + default "mq-deadline" if DEFAULT_SQ_DEADLINE + default "none" if DEFAULT_SQ_NONE + +choice + prompt "Default multi-queue blk-mq I/O scheduler" + default DEFAULT_MQ_NONE + help + Select the I/O scheduler which will be used by default for blk-mq + managed block devices with multiple queues. + + config DEFAULT_MQ_DEADLINE + bool "MQ Deadline" if MQ_IOSCHED_DEADLINE=y + + config DEFAULT_MQ_NONE + bool "None" + +endchoice + +config DEFAULT_MQ_IOSCHED + string + default "mq-deadline" if DEFAULT_MQ_DEADLINE + default "none" if DEFAULT_MQ_NONE + endmenu endif diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index 26759798a0b3..d05061f27bb1 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -366,3 +366,23 @@ void blk_mq_sched_teardown(struct request_queue *q) queue_for_each_hw_ctx(q, hctx, i) blk_mq_sched_free_tags(set, hctx, i); } + +int blk_mq_sched_init(struct request_queue *q) +{ + int ret; + +#if defined(CONFIG_DEFAULT_SQ_NONE) + if (q->nr_hw_queues == 1) + return 0; +#endif +#if defined(CONFIG_DEFAULT_MQ_NONE) + if (q->nr_hw_queues > 1) + return 0; +#endif + + mutex_lock(&q->sysfs_lock); + ret = elevator_init(q, NULL); + mutex_unlock(&q->sysfs_lock); + + return ret; +} diff --git a/block/blk-mq-sched.h b/block/blk-mq-sched.h index 35c49e2e008a..6b465bc7014c 100644 --- a/block/blk-mq-sched.h +++ b/block/blk-mq-sched.h @@ -28,6 +28,8 @@ void blk_mq_sched_move_to_dispatch(struct blk_mq_hw_ctx *hctx, int blk_mq_sched_setup(struct request_queue *q); void blk_mq_sched_teardown(struct request_queue *q); +int blk_mq_sched_init(struct request_queue *q); + static inline bool blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio) { diff --git a/block/blk-mq.c b/block/blk-mq.c index 45e1707a9f86..fa1f8619bfe7 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2285,6 +2285,14 @@ struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, mutex_unlock(&all_q_mutex); put_online_cpus(); + if (!(set->flags & BLK_MQ_F_NO_SCHED)) { + int ret; + + ret = blk_mq_sched_init(q); + if (ret) + return ERR_PTR(ret); + } + return q; err_hctxs: diff --git a/block/elevator.c b/block/elevator.c index 0e1ccddab8a2..bcba2dd5cb5c 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -219,7 +219,13 @@ int elevator_init(struct request_queue *q, char *name) } if (!e) { - e = elevator_get(CONFIG_DEFAULT_IOSCHED, false); + if (q->mq_ops && q->nr_hw_queues == 1) + e = elevator_get(CONFIG_DEFAULT_SQ_IOSCHED, false); + else if (q->mq_ops) + e = elevator_get(CONFIG_DEFAULT_MQ_IOSCHED, false); + else + e = elevator_get(CONFIG_DEFAULT_IOSCHED, false); + if (!e) { printk(KERN_ERR "Default I/O scheduler not found. " \ diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index 19beeb7b2ac2..e1b4e603b1cf 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -1181,6 +1181,7 @@ static int nvme_alloc_admin_tags(struct nvme_dev *dev) dev->admin_tagset.timeout = ADMIN_TIMEOUT; dev->admin_tagset.numa_node = dev_to_node(dev->dev); dev->admin_tagset.cmd_size = nvme_cmd_size(dev); + dev->admin_tagset.flags = BLK_MQ_F_NO_SCHED; dev->admin_tagset.driver_data = dev; if (blk_mq_alloc_tag_set(&dev->admin_tagset)) diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 63569eb46d15..8e4df3d6c8cd 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -153,6 +153,7 @@ enum { BLK_MQ_F_SG_MERGE = 1 << 2, BLK_MQ_F_DEFER_ISSUE = 1 << 4, BLK_MQ_F_BLOCKING = 1 << 5, + BLK_MQ_F_NO_SCHED = 1 << 6, BLK_MQ_F_ALLOC_POLICY_START_BIT = 8, BLK_MQ_F_ALLOC_POLICY_BITS = 1, From 4d199c6f1c847151ea393d5b9946a17cc57cdf6d Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 18 Jan 2017 07:43:26 -0700 Subject: [PATCH 17/49] blk-cgroup: ensure that we clear the stop bit on quiesced queues If we call blk_mq_quiesce_queue() on a queue, we must remember to pair that with something that clears the stopped by on the queues later on. Signed-off-by: Jens Axboe --- block/blk-cgroup.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 2630f64bed19..efb97ec37eee 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -1265,9 +1265,10 @@ pd_prealloc: spin_unlock_irq(q->queue_lock); out_bypass_end: - if (q->mq_ops) + if (q->mq_ops) { blk_mq_unfreeze_queue(q); - else + blk_mq_start_stopped_hw_queues(q, true); + } else blk_queue_bypass_end(q); if (pd_prealloc) pol->pd_free_fn(pd_prealloc); @@ -1317,9 +1318,10 @@ void blkcg_deactivate_policy(struct request_queue *q, spin_unlock_irq(q->queue_lock); - if (q->mq_ops) + if (q->mq_ops) { blk_mq_unfreeze_queue(q); - else + blk_mq_start_stopped_hw_queues(q, true); + } else blk_queue_bypass_end(q); } EXPORT_SYMBOL_GPL(blkcg_deactivate_policy); From f66227de5924ed0fde1823f5cbc4d8b8f45faaa2 Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Wed, 18 Jan 2017 11:55:21 -0800 Subject: [PATCH 18/49] sbitmap: use smp_mb__after_atomic() in sbq_wake_up() We always do an atomic clear_bit() right before we call sbq_wake_up(), so we can use smp_mb__after_atomic(). While we're here, comment the memory barriers in here a little more. Signed-off-by: Omar Sandoval Signed-off-by: Jens Axboe --- lib/sbitmap.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/lib/sbitmap.c b/lib/sbitmap.c index 2cecf05c82fd..df4e472df8a3 100644 --- a/lib/sbitmap.c +++ b/lib/sbitmap.c @@ -299,8 +299,14 @@ static void sbq_wake_up(struct sbitmap_queue *sbq) struct sbq_wait_state *ws; int wait_cnt; - /* Ensure that the wait list checks occur after clear_bit(). */ - smp_mb(); + /* + * Pairs with the memory barrier in set_current_state() to ensure the + * proper ordering of clear_bit()/waitqueue_active() in the waker and + * test_and_set_bit()/prepare_to_wait()/finish_wait() in the waiter. See + * the comment on waitqueue_active(). This is __after_atomic because we + * just did clear_bit() in the caller. + */ + smp_mb__after_atomic(); ws = sbq_wake_ptr(sbq); if (!ws) @@ -331,7 +337,8 @@ void sbitmap_queue_wake_all(struct sbitmap_queue *sbq) int i, wake_index; /* - * Make sure all changes prior to this are visible from other CPUs. + * Pairs with the memory barrier in set_current_state() like in + * sbq_wake_up(). */ smp_mb(); wake_index = atomic_read(&sbq->wake_index); From 6c0ca7ae292adea09b8bdd33a524bb9326c3e989 Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Wed, 18 Jan 2017 11:55:22 -0800 Subject: [PATCH 19/49] sbitmap: fix wakeup hang after sbq resize When we resize a struct sbitmap_queue, we update the wakeup batch size, but we don't update the wait count in the struct sbq_wait_states. If we resized down from a size which could use a bigger batch size, these counts could be too large and cause us to miss necessary wakeups. To fix this, update the wait counts when we resize (ensuring some careful memory ordering so that it's safe w.r.t. concurrent clears). This also fixes a theoretical issue where two threads could end up bumping the wait count up by the batch size, which could also potentially lead to hangs. Reported-by: Martin Raiber Fixes: e3a2b3f931f5 ("blk-mq: allow changing of queue depth through sysfs") Fixes: 2971c35f3588 ("blk-mq: bitmap tag: fix race on blk_mq_bitmap_tags::wake_cnt") Signed-off-by: Omar Sandoval Signed-off-by: Jens Axboe --- lib/sbitmap.c | 35 ++++++++++++++++++++++++++++++----- 1 file changed, 30 insertions(+), 5 deletions(-) diff --git a/lib/sbitmap.c b/lib/sbitmap.c index df4e472df8a3..8f5c3b268c77 100644 --- a/lib/sbitmap.c +++ b/lib/sbitmap.c @@ -239,7 +239,19 @@ EXPORT_SYMBOL_GPL(sbitmap_queue_init_node); void sbitmap_queue_resize(struct sbitmap_queue *sbq, unsigned int depth) { - sbq->wake_batch = sbq_calc_wake_batch(depth); + unsigned int wake_batch = sbq_calc_wake_batch(depth); + int i; + + if (sbq->wake_batch != wake_batch) { + WRITE_ONCE(sbq->wake_batch, wake_batch); + /* + * Pairs with the memory barrier in sbq_wake_up() to ensure that + * the batch size is updated before the wait counts. + */ + smp_mb__before_atomic(); + for (i = 0; i < SBQ_WAIT_QUEUES; i++) + atomic_set(&sbq->ws[i].wait_cnt, 1); + } sbitmap_resize(&sbq->sb, depth); } EXPORT_SYMBOL_GPL(sbitmap_queue_resize); @@ -297,6 +309,7 @@ static struct sbq_wait_state *sbq_wake_ptr(struct sbitmap_queue *sbq) static void sbq_wake_up(struct sbitmap_queue *sbq) { struct sbq_wait_state *ws; + unsigned int wake_batch; int wait_cnt; /* @@ -313,10 +326,22 @@ static void sbq_wake_up(struct sbitmap_queue *sbq) return; wait_cnt = atomic_dec_return(&ws->wait_cnt); - if (unlikely(wait_cnt < 0)) - wait_cnt = atomic_inc_return(&ws->wait_cnt); - if (wait_cnt == 0) { - atomic_add(sbq->wake_batch, &ws->wait_cnt); + if (wait_cnt <= 0) { + wake_batch = READ_ONCE(sbq->wake_batch); + /* + * Pairs with the memory barrier in sbitmap_queue_resize() to + * ensure that we see the batch size update before the wait + * count is reset. + */ + smp_mb__before_atomic(); + /* + * If there are concurrent callers to sbq_wake_up(), the last + * one to decrement the wait count below zero will bump it back + * up. If there is a concurrent resize, the count reset will + * either cause the cmpxchg to fail or overwrite after the + * cmpxchg. + */ + atomic_cmpxchg(&ws->wait_cnt, wait_cnt, wait_cnt + wake_batch); sbq_index_atomic_inc(&sbq->wake_index); wake_up(&ws->wait); } From 38dbb7dd4db184da4d2673f4bb963f7006465c37 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 18 Jan 2017 15:37:27 -0700 Subject: [PATCH 20/49] blk-cgroup: don't quiesce the queue on policy activate/deactivate There's no potential harm in quiescing the queue, but it also doesn't buy us anything. And we can't run the queue async for policy deactivate, since we could be in the path of tearing the queue down. If we schedule an async run of the queue at that time, we're racing with queue teardown AFTER having we've already torn most of it down. Reported-by: Omar Sandoval Fixes: 4d199c6f1c84 ("blk-cgroup: ensure that we clear the stop bit on quiesced queues") Tested-by: Omar Sandoval Signed-off-by: Jens Axboe --- block/blk-cgroup.c | 20 ++++++++------------ 1 file changed, 8 insertions(+), 12 deletions(-) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index efb97ec37eee..fb59a3edc778 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -1223,10 +1223,9 @@ int blkcg_activate_policy(struct request_queue *q, if (blkcg_policy_enabled(q, pol)) return 0; - if (q->mq_ops) { + if (q->mq_ops) blk_mq_freeze_queue(q); - blk_mq_quiesce_queue(q); - } else + else blk_queue_bypass_start(q); pd_prealloc: if (!pd_prealloc) { @@ -1265,10 +1264,9 @@ pd_prealloc: spin_unlock_irq(q->queue_lock); out_bypass_end: - if (q->mq_ops) { + if (q->mq_ops) blk_mq_unfreeze_queue(q); - blk_mq_start_stopped_hw_queues(q, true); - } else + else blk_queue_bypass_end(q); if (pd_prealloc) pol->pd_free_fn(pd_prealloc); @@ -1292,10 +1290,9 @@ void blkcg_deactivate_policy(struct request_queue *q, if (!blkcg_policy_enabled(q, pol)) return; - if (q->mq_ops) { + if (q->mq_ops) blk_mq_freeze_queue(q); - blk_mq_quiesce_queue(q); - } else + else blk_queue_bypass_start(q); spin_lock_irq(q->queue_lock); @@ -1318,10 +1315,9 @@ void blkcg_deactivate_policy(struct request_queue *q, spin_unlock_irq(q->queue_lock); - if (q->mq_ops) { + if (q->mq_ops) blk_mq_unfreeze_queue(q); - blk_mq_start_stopped_hw_queues(q, true); - } else + else blk_queue_bypass_end(q); } EXPORT_SYMBOL_GPL(blkcg_deactivate_policy); From 610d886c0c22fa7504e817b6d03c402de64b0264 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 19 Jan 2017 07:10:13 -0700 Subject: [PATCH 21/49] elevator: fix unnecessary put of elevator in failure case We already checked that e is NULL, so no point in calling elevator_put() to free it. Reported-by: Dan Carpenter Fixes: dc877dbd088f ("blk-mq-sched: add framework for MQ capable IO schedulers") Signed-off-by: Jens Axboe --- block/elevator.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/block/elevator.c b/block/elevator.c index bcba2dd5cb5c..ef7f59469acc 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -230,10 +230,6 @@ int elevator_init(struct request_queue *q, char *name) printk(KERN_ERR "Default I/O scheduler not found. " \ "Using noop/none.\n"); - if (q->mq_ops) { - elevator_put(e); - return 0; - } e = elevator_get("noop", false); } } From 8cecb07d70e761eb0112f921d939b9ab2ea2171f Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 19 Jan 2017 07:39:17 -0700 Subject: [PATCH 22/49] blk-mq-tag: remove redundant check for 'data->hctx' being non-NULL We used to pass in NULL for hctx for reserved tags, but we don't do that anymore. Hence the check for whether hctx is NULL or not is now redundant, kill it. Reported-by: Dan Carpenter Fixes: a642a158aec6 ("blk-mq-tag: cleanup the normal/reserved tag allocation") Signed-off-by: Jens Axboe --- block/blk-mq-tag.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index 9753747a34a2..5504eb7ed10b 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -136,11 +136,9 @@ unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data) /* * We're out of tags on this hardware queue, kick any * pending IO submits before going to sleep waiting for - * some to complete. Note that hctx can be NULL here for - * reserved tag allocation. + * some to complete. */ - if (data->hctx) - blk_mq_run_hw_queue(data->hctx, false); + blk_mq_run_hw_queue(data->hctx, false); /* * Retry tag allocation after running the hardware queue, From 7e79dadce222e06e0c30a77280f3426014bee185 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 19 Jan 2017 07:58:59 -0700 Subject: [PATCH 23/49] blk-mq: stop hardware queue in blk_mq_delay_queue() The run handler we register for the delayed work requires that the queue be stopped, yet we leave that up to the caller. Let's move it into blk_mq_delay_queue() itself, so that the API is sane. This fixes a stall with SCSI, where it calls blk_mq_delay_queue() without having stopped the queue. Hence the queue is never run. Reported-by: Hannes Reinecke Fixes: 70f4db639c5b ("blk-mq: add blk_mq_delay_queue") Signed-off-by: Jens Axboe --- block/blk-mq.c | 1 + 1 file changed, 1 insertion(+) diff --git a/block/blk-mq.c b/block/blk-mq.c index fa1f8619bfe7..b365cde4c909 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1170,6 +1170,7 @@ void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs) if (unlikely(!blk_mq_hw_queue_mapped(hctx))) return; + blk_mq_stop_hw_queue(hctx); kblockd_schedule_delayed_work_on(blk_mq_hctx_next_cpu(hctx), &hctx->delay_work, msecs_to_jiffies(msecs)); } From 70f36b6001bf596eb411c4b302e84c4824ae8730 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 19 Jan 2017 10:59:07 -0700 Subject: [PATCH 24/49] blk-mq: allow resize of scheduler requests Add support for growing the tags associated with a hardware queue, for the scheduler tags. Currently we only support resizing within the limits of the original depth, change that so we can grow it as well by allocating and replacing the existing scheduler tag set. This is similar to how we could increase the software queue depth with the legacy IO stack and schedulers. Signed-off-by: Jens Axboe Reviewed-by: Omar Sandoval --- block/blk-mq-tag.c | 55 ++++++++++++++++++++++++++++++++++++++-------- block/blk-mq-tag.h | 4 +++- block/blk-mq.c | 19 +++++++++++----- 3 files changed, 63 insertions(+), 15 deletions(-) diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index 5504eb7ed10b..a49ec77c415a 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -387,19 +387,56 @@ void blk_mq_free_tags(struct blk_mq_tags *tags) kfree(tags); } -int blk_mq_tag_update_depth(struct blk_mq_tags *tags, unsigned int tdepth) +int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx, + struct blk_mq_tags **tagsptr, unsigned int tdepth, + bool can_grow) { - tdepth -= tags->nr_reserved_tags; - if (tdepth > tags->nr_tags) + struct blk_mq_tags *tags = *tagsptr; + + if (tdepth <= tags->nr_reserved_tags) return -EINVAL; - /* - * Don't need (or can't) update reserved tags here, they remain - * static and should never need resizing. - */ - sbitmap_queue_resize(&tags->bitmap_tags, tdepth); + tdepth -= tags->nr_reserved_tags; + + /* + * If we are allowed to grow beyond the original size, allocate + * a new set of tags before freeing the old one. + */ + if (tdepth > tags->nr_tags) { + struct blk_mq_tag_set *set = hctx->queue->tag_set; + struct blk_mq_tags *new; + bool ret; + + if (!can_grow) + return -EINVAL; + + /* + * We need some sort of upper limit, set it high enough that + * no valid use cases should require more. + */ + if (tdepth > 16 * BLKDEV_MAX_RQ) + return -EINVAL; + + new = blk_mq_alloc_rq_map(set, hctx->queue_num, tdepth, 0); + if (!new) + return -ENOMEM; + ret = blk_mq_alloc_rqs(set, new, hctx->queue_num, tdepth); + if (ret) { + blk_mq_free_rq_map(new); + return -ENOMEM; + } + + blk_mq_free_rqs(set, *tagsptr, hctx->queue_num); + blk_mq_free_rq_map(*tagsptr); + *tagsptr = new; + } else { + /* + * Don't need (or can't) update reserved tags here, they + * remain static and should never need resizing. + */ + sbitmap_queue_resize(&tags->bitmap_tags, tdepth); + } - blk_mq_tag_wakeup_all(tags, false); return 0; } diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h index 41cd15fd1afd..ac22878462e7 100644 --- a/block/blk-mq-tag.h +++ b/block/blk-mq-tag.h @@ -29,7 +29,9 @@ extern void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, struct blk_mq_tags *tags, struct blk_mq_ctx *ctx, unsigned int tag); extern bool blk_mq_has_free_tags(struct blk_mq_tags *tags); extern ssize_t blk_mq_tag_sysfs_show(struct blk_mq_tags *tags, char *page); -extern int blk_mq_tag_update_depth(struct blk_mq_tags *tags, unsigned int depth); +extern int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx, + struct blk_mq_tags **tags, + unsigned int depth, bool can_grow); extern void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags, bool); void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn, void *priv); diff --git a/block/blk-mq.c b/block/blk-mq.c index b365cde4c909..ee69e5e89769 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2561,6 +2561,9 @@ int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr) if (!set) return -EINVAL; + blk_mq_freeze_queue(q); + blk_mq_quiesce_queue(q); + ret = 0; queue_for_each_hw_ctx(q, hctx, i) { if (!hctx->tags) @@ -2569,11 +2572,14 @@ int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr) * If we're using an MQ scheduler, just update the scheduler * queue depth. This is similar to what the old code would do. */ - if (!hctx->sched_tags) - ret = blk_mq_tag_update_depth(hctx->tags, - min(nr, set->queue_depth)); - else - ret = blk_mq_tag_update_depth(hctx->sched_tags, nr); + if (!hctx->sched_tags) { + ret = blk_mq_tag_update_depth(hctx, &hctx->tags, + min(nr, set->queue_depth), + false); + } else { + ret = blk_mq_tag_update_depth(hctx, &hctx->sched_tags, + nr, true); + } if (ret) break; } @@ -2581,6 +2587,9 @@ int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr) if (!ret) q->nr_requests = nr; + blk_mq_unfreeze_queue(q); + blk_mq_start_stopped_hw_queues(q, true); + return ret; } From 4d608baac5f4e72b033a122b2d6d9499532c3afc Mon Sep 17 00:00:00 2001 From: Alexander Potapenko Date: Mon, 23 Jan 2017 15:06:43 +0100 Subject: [PATCH 25/49] block: Initialize cfqq->ioprio_class in cfq_get_queue() KMSAN (KernelMemorySanitizer, a new error detection tool) reports use of uninitialized memory in cfq_init_cfqq(): ================================================================== BUG: KMSAN: use of unitialized memory ... Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [] dump_stack+0x157/0x1d0 lib/dump_stack.c:51 [] kmsan_report+0x205/0x360 ??:? [] __msan_warning+0x5b/0xb0 ??:? [< inline >] cfq_init_cfqq block/cfq-iosched.c:3754 [] cfq_get_queue+0xc80/0x14d0 block/cfq-iosched.c:3857 ... origin: [] save_stack_trace+0x27/0x50 arch/x86/kernel/stacktrace.c:67 [] kmsan_internal_poison_shadow+0xab/0x150 ??:? [] kmsan_poison_slab+0xbb/0x120 ??:? [< inline >] allocate_slab mm/slub.c:1627 [] new_slab+0x3af/0x4b0 mm/slub.c:1641 [< inline >] new_slab_objects mm/slub.c:2407 [] ___slab_alloc+0x323/0x4a0 mm/slub.c:2564 [< inline >] __slab_alloc mm/slub.c:2606 [< inline >] slab_alloc_node mm/slub.c:2669 [] kmem_cache_alloc_node+0x1d2/0x1f0 mm/slub.c:2746 [] cfq_get_queue+0x47d/0x14d0 block/cfq-iosched.c:3850 ... ================================================================== (the line numbers are relative to 4.8-rc6, but the bug persists upstream) The uninitialized struct cfq_queue is created by kmem_cache_alloc_node() and then passed to cfq_init_cfqq(), which accesses cfqq->ioprio_class before it's initialized. Signed-off-by: Alexander Potapenko Signed-off-by: Jens Axboe --- block/cfq-iosched.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 37aeb20fa454..c472886c727f 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -3864,6 +3864,8 @@ cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct cfq_io_cq *cic, goto out; } + /* cfq_init_cfqq() assumes cfqq->ioprio_class is initialized. */ + cfqq->ioprio_class = IOPRIO_CLASS_NONE; cfq_init_cfqq(cfqd, cfqq, current->pid, is_sync); cfq_init_prio_data(cfqq, cic); cfq_link_cfqq_cfqg(cfqq, cfqg); From d609af3a1397511a7a2c213f9f855fa82df771ee Mon Sep 17 00:00:00 2001 From: Markus Elfring Date: Sat, 21 Jan 2017 22:15:33 +0100 Subject: [PATCH 26/49] blk-throttle: Adjust two function calls together with a variable assignment The script "checkpatch.pl" pointed information out like the following. ERROR: do not use assignment in if condition Thus fix the affected source code places. Signed-off-by: Markus Elfring Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe --- block/blk-throttle.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/block/blk-throttle.c b/block/blk-throttle.c index a6bb4fe326c3..82fd0cc394eb 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -866,10 +866,12 @@ static void tg_update_disptime(struct throtl_grp *tg) unsigned long read_wait = -1, write_wait = -1, min_wait = -1, disptime; struct bio *bio; - if ((bio = throtl_peek_queued(&sq->queued[READ]))) + bio = throtl_peek_queued(&sq->queued[READ]); + if (bio) tg_may_dispatch(tg, bio, &read_wait); - if ((bio = throtl_peek_queued(&sq->queued[WRITE]))) + bio = throtl_peek_queued(&sq->queued[WRITE]); + if (bio) tg_may_dispatch(tg, bio, &write_wait); min_wait = min(read_wait, write_wait); From 1cf417530375b475d4a8a9f18dc0867f91e52d78 Mon Sep 17 00:00:00 2001 From: Markus Elfring Date: Sat, 21 Jan 2017 22:44:07 +0100 Subject: [PATCH 27/49] cfq-iosched: Adjust one function call together with a variable assignment The script "checkpatch.pl" pointed information out like the following. ERROR: do not use assignment in if condition Thus fix the affected source code place. Signed-off-by: Markus Elfring Signed-off-by: Jens Axboe --- block/cfq-iosched.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index c472886c727f..f0f29ee731e1 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -2749,9 +2749,11 @@ static struct cfq_queue *cfq_get_next_queue_forced(struct cfq_data *cfqd) if (!cfqg) return NULL; - for_each_cfqg_st(cfqg, i, j, st) - if ((cfqq = cfq_rb_first(st)) != NULL) + for_each_cfqg_st(cfqg, i, j, st) { + cfqq = cfq_rb_first(st); + if (cfqq) return cfqq; + } return NULL; } From 200e86b3372b51e136a382e007b6b904b1dac7e4 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 25 Jan 2017 08:11:38 -0700 Subject: [PATCH 28/49] blk-mq: only apply active queue tag throttling for driver tags If we have a scheduler attached, we have two sets of tags. We don't want to apply our active queue throttling for the scheduler side of tags, that only applies to driver tags since that's the resource we need to dispatch an IO. Signed-off-by: Jens Axboe --- block/blk-mq-tag.c | 12 +++++++----- block/blk-mq.c | 13 ++++++++----- 2 files changed, 15 insertions(+), 10 deletions(-) diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index a49ec77c415a..1b156ca79af6 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -90,9 +90,11 @@ static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx, return atomic_read(&hctx->nr_active) < depth; } -static int __blk_mq_get_tag(struct blk_mq_hw_ctx *hctx, struct sbitmap_queue *bt) +static int __blk_mq_get_tag(struct blk_mq_alloc_data *data, + struct sbitmap_queue *bt) { - if (!hctx_may_queue(hctx, bt)) + if (!(data->flags & BLK_MQ_REQ_INTERNAL) && + !hctx_may_queue(data->hctx, bt)) return -1; return __sbitmap_queue_get(bt); } @@ -118,7 +120,7 @@ unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data) tag_offset = tags->nr_reserved_tags; } - tag = __blk_mq_get_tag(data->hctx, bt); + tag = __blk_mq_get_tag(data, bt); if (tag != -1) goto found_tag; @@ -129,7 +131,7 @@ unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data) do { prepare_to_wait(&ws->wait, &wait, TASK_UNINTERRUPTIBLE); - tag = __blk_mq_get_tag(data->hctx, bt); + tag = __blk_mq_get_tag(data, bt); if (tag != -1) break; @@ -144,7 +146,7 @@ unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data) * Retry tag allocation after running the hardware queue, * as running the queue may also have found completions. */ - tag = __blk_mq_get_tag(data->hctx, bt); + tag = __blk_mq_get_tag(data, bt); if (tag != -1) break; diff --git a/block/blk-mq.c b/block/blk-mq.c index ee69e5e89769..dcb567642db7 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -230,15 +230,14 @@ struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data, rq = tags->static_rqs[tag]; - if (blk_mq_tag_busy(data->hctx)) { - rq->rq_flags = RQF_MQ_INFLIGHT; - atomic_inc(&data->hctx->nr_active); - } - if (data->flags & BLK_MQ_REQ_INTERNAL) { rq->tag = -1; rq->internal_tag = tag; } else { + if (blk_mq_tag_busy(data->hctx)) { + rq->rq_flags = RQF_MQ_INFLIGHT; + atomic_inc(&data->hctx->nr_active); + } rq->tag = tag; rq->internal_tag = -1; } @@ -869,6 +868,10 @@ done: rq->tag = blk_mq_get_tag(&data); if (rq->tag >= 0) { + if (blk_mq_tag_busy(data.hctx)) { + rq->rq_flags |= RQF_MQ_INFLIGHT; + atomic_inc(&data.hctx->nr_active); + } data.hctx->tags->rqs[rq->tag] = rq; goto done; } From 5a797e00dc93593c9915841779881b15d9856237 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 26 Jan 2017 12:22:11 -0700 Subject: [PATCH 29/49] blk-mq: don't lose flags passed in to blk_mq_alloc_request() If we come in from blk_mq_alloc_requst() with NOWAIT set in flags, we must ensure that we don't later overwrite that in blk_mq_sched_get_request(). Initialize alloc_data->flags before passing it in. Reported-by: Bart Van Assche Signed-off-by: Jens Axboe --- block/blk-mq-sched.c | 2 +- block/blk-mq.c | 6 +++--- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index d05061f27bb1..56b92db944ae 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -117,7 +117,7 @@ struct request *blk_mq_sched_get_request(struct request_queue *q, ctx = blk_mq_get_ctx(q); hctx = blk_mq_map_queue(q, ctx->cpu); - blk_mq_set_alloc_data(data, q, 0, ctx, hctx); + blk_mq_set_alloc_data(data, q, data->flags, ctx, hctx); if (e) { data->flags |= BLK_MQ_REQ_INTERNAL; diff --git a/block/blk-mq.c b/block/blk-mq.c index dcb567642db7..84d13b5cafd0 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -253,7 +253,7 @@ EXPORT_SYMBOL_GPL(__blk_mq_alloc_request); struct request *blk_mq_alloc_request(struct request_queue *q, int rw, unsigned int flags) { - struct blk_mq_alloc_data alloc_data; + struct blk_mq_alloc_data alloc_data = { .flags = flags }; struct request *rq; int ret; @@ -1382,7 +1382,7 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) { const int is_sync = op_is_sync(bio->bi_opf); const int is_flush_fua = bio->bi_opf & (REQ_PREFLUSH | REQ_FUA); - struct blk_mq_alloc_data data; + struct blk_mq_alloc_data data = { .flags = 0 }; struct request *rq; unsigned int request_count = 0, srcu_idx; struct blk_plug *plug; @@ -1504,7 +1504,7 @@ static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio) const int is_flush_fua = bio->bi_opf & (REQ_PREFLUSH | REQ_FUA); struct blk_plug *plug; unsigned int request_count = 0; - struct blk_mq_alloc_data data; + struct blk_mq_alloc_data data = { .flags = 0 }; struct request *rq; blk_qc_t cookie; unsigned int wb_acct; From b48fda0976a802e0fe4fc0bedefb7cf380ec6426 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 26 Jan 2017 14:52:20 -0700 Subject: [PATCH 30/49] blk-mq-sched: check for successful allocation before assigning tag We don't trigger this from the normal IO path, since we always use blocking allocations from there. But Bart saw it testing multipath dm, since that is a heavy user of atomic request allocations in the map and clone path. Reported-by: Bart Van Assche Signed-off-by: Jens Axboe --- block/blk-mq-sched.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index 56b92db944ae..4cee060a292d 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -134,7 +134,8 @@ struct request *blk_mq_sched_get_request(struct request_queue *q, rq = __blk_mq_alloc_request(data, op); } else { rq = __blk_mq_alloc_request(data, op); - data->hctx->tags->rqs[rq->tag] = rq; + if (rq) + data->hctx->tags->rqs[rq->tag] = rq; } if (rq) { From 07e4fead45e6e1932f0b960655ab554b6aab6a08 Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Wed, 25 Jan 2017 08:06:40 -0800 Subject: [PATCH 31/49] blk-mq: create debugfs directory tree In preparation for putting blk-mq debugging information in debugfs, create a directory tree mirroring the one in sysfs: # tree -d /sys/kernel/debug/block /sys/kernel/debug/block |-- nvme0n1 | `-- mq | |-- 0 | | `-- cpu0 | |-- 1 | | `-- cpu1 | |-- 2 | | `-- cpu2 | `-- 3 | `-- cpu3 `-- vda `-- mq `-- 0 |-- cpu0 |-- cpu1 |-- cpu2 `-- cpu3 Also add the scaffolding for the actual files that will go in here, either under the hardware queue or software queue directories. Reviewed-by: Hannes Reinecke Signed-off-by: Omar Sandoval Signed-off-by: Jens Axboe --- block/Makefile | 1 + block/blk-mq-debugfs.c | 152 +++++++++++++++++++++++++++++++++++++++++ block/blk-mq-sysfs.c | 8 +++ block/blk-mq.c | 2 + block/blk-mq.h | 33 +++++++++ include/linux/blkdev.h | 5 ++ 6 files changed, 201 insertions(+) create mode 100644 block/blk-mq-debugfs.c diff --git a/block/Makefile b/block/Makefile index 3ee0abd7205a..6cabe6bd2882 100644 --- a/block/Makefile +++ b/block/Makefile @@ -26,3 +26,4 @@ obj-$(CONFIG_BLK_DEV_INTEGRITY) += bio-integrity.o blk-integrity.o t10-pi.o obj-$(CONFIG_BLK_MQ_PCI) += blk-mq-pci.o obj-$(CONFIG_BLK_DEV_ZONED) += blk-zoned.o obj-$(CONFIG_BLK_WBT) += blk-wbt.o +obj-$(CONFIG_DEBUG_FS) += blk-mq-debugfs.o diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c new file mode 100644 index 000000000000..01711bbf5ade --- /dev/null +++ b/block/blk-mq-debugfs.c @@ -0,0 +1,152 @@ +/* + * Copyright (C) 2017 Facebook + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + +#include +#include +#include + +#include +#include "blk-mq.h" + +struct blk_mq_debugfs_attr { + const char *name; + umode_t mode; + const struct file_operations *fops; +}; + +static struct dentry *block_debugfs_root; + +static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = { +}; + +static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = { +}; + +int blk_mq_debugfs_register(struct request_queue *q, const char *name) +{ + if (!block_debugfs_root) + return -ENOENT; + + q->debugfs_dir = debugfs_create_dir(name, block_debugfs_root); + if (!q->debugfs_dir) + goto err; + + if (blk_mq_debugfs_register_hctxs(q)) + goto err; + + return 0; + +err: + blk_mq_debugfs_unregister(q); + return -ENOMEM; +} + +void blk_mq_debugfs_unregister(struct request_queue *q) +{ + debugfs_remove_recursive(q->debugfs_dir); + q->mq_debugfs_dir = NULL; + q->debugfs_dir = NULL; +} + +static int blk_mq_debugfs_register_ctx(struct request_queue *q, + struct blk_mq_ctx *ctx, + struct dentry *hctx_dir) +{ + struct dentry *ctx_dir; + char name[20]; + int i; + + snprintf(name, sizeof(name), "cpu%u", ctx->cpu); + ctx_dir = debugfs_create_dir(name, hctx_dir); + if (!ctx_dir) + return -ENOMEM; + + for (i = 0; i < ARRAY_SIZE(blk_mq_debugfs_ctx_attrs); i++) { + const struct blk_mq_debugfs_attr *attr; + + attr = &blk_mq_debugfs_ctx_attrs[i]; + if (!debugfs_create_file(attr->name, attr->mode, ctx_dir, ctx, + attr->fops)) + return -ENOMEM; + } + + return 0; +} + +static int blk_mq_debugfs_register_hctx(struct request_queue *q, + struct blk_mq_hw_ctx *hctx) +{ + struct blk_mq_ctx *ctx; + struct dentry *hctx_dir; + char name[20]; + int i; + + snprintf(name, sizeof(name), "%u", hctx->queue_num); + hctx_dir = debugfs_create_dir(name, q->mq_debugfs_dir); + if (!hctx_dir) + return -ENOMEM; + + for (i = 0; i < ARRAY_SIZE(blk_mq_debugfs_hctx_attrs); i++) { + const struct blk_mq_debugfs_attr *attr; + + attr = &blk_mq_debugfs_hctx_attrs[i]; + if (!debugfs_create_file(attr->name, attr->mode, hctx_dir, hctx, + attr->fops)) + return -ENOMEM; + } + + hctx_for_each_ctx(hctx, ctx, i) { + if (blk_mq_debugfs_register_ctx(q, ctx, hctx_dir)) + return -ENOMEM; + } + + return 0; +} + +int blk_mq_debugfs_register_hctxs(struct request_queue *q) +{ + struct blk_mq_hw_ctx *hctx; + int i; + + if (!q->debugfs_dir) + return -ENOENT; + + q->mq_debugfs_dir = debugfs_create_dir("mq", q->debugfs_dir); + if (!q->mq_debugfs_dir) + goto err; + + queue_for_each_hw_ctx(q, hctx, i) { + if (blk_mq_debugfs_register_hctx(q, hctx)) + goto err; + } + + return 0; + +err: + blk_mq_debugfs_unregister_hctxs(q); + return -ENOMEM; +} + +void blk_mq_debugfs_unregister_hctxs(struct request_queue *q) +{ + debugfs_remove_recursive(q->mq_debugfs_dir); + q->mq_debugfs_dir = NULL; +} + +void blk_mq_debugfs_init(void) +{ + block_debugfs_root = debugfs_create_dir("block", NULL); +} diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c index 2caecaa98e40..91b93ca1c1e0 100644 --- a/block/blk-mq-sysfs.c +++ b/block/blk-mq-sysfs.c @@ -468,6 +468,8 @@ static void __blk_mq_unregister_dev(struct device *dev, struct request_queue *q) kobject_put(&hctx->kobj); } + blk_mq_debugfs_unregister(q); + kobject_uevent(&q->mq_kobj, KOBJ_REMOVE); kobject_del(&q->mq_kobj); kobject_put(&q->mq_kobj); @@ -517,6 +519,8 @@ int blk_mq_register_dev(struct device *dev, struct request_queue *q) kobject_uevent(&q->mq_kobj, KOBJ_ADD); + blk_mq_debugfs_register(q, kobject_name(&dev->kobj)); + queue_for_each_hw_ctx(q, hctx, i) { ret = blk_mq_register_hctx(hctx); if (ret) @@ -542,6 +546,8 @@ void blk_mq_sysfs_unregister(struct request_queue *q) if (!q->mq_sysfs_init_done) return; + blk_mq_debugfs_unregister_hctxs(q); + queue_for_each_hw_ctx(q, hctx, i) blk_mq_unregister_hctx(hctx); } @@ -554,6 +560,8 @@ int blk_mq_sysfs_register(struct request_queue *q) if (!q->mq_sysfs_init_done) return ret; + blk_mq_debugfs_register_hctxs(q); + queue_for_each_hw_ctx(q, hctx, i) { ret = blk_mq_register_hctx(hctx); if (ret) diff --git a/block/blk-mq.c b/block/blk-mq.c index 84d13b5cafd0..ede835c2b08b 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2799,6 +2799,8 @@ void blk_mq_enable_hotplug(void) static int __init blk_mq_init(void) { + blk_mq_debugfs_init(); + cpuhp_setup_state_multi(CPUHP_BLK_MQ_DEAD, "block/mq:dead", NULL, blk_mq_hctx_notify_dead); diff --git a/block/blk-mq.h b/block/blk-mq.h index 0c7c034d9ddd..6c24b901acd7 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -78,6 +78,39 @@ extern int blk_mq_sysfs_register(struct request_queue *q); extern void blk_mq_sysfs_unregister(struct request_queue *q); extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx); +/* + * debugfs helpers + */ +#ifdef CONFIG_DEBUG_FS +void blk_mq_debugfs_init(void); +int blk_mq_debugfs_register(struct request_queue *q, const char *name); +void blk_mq_debugfs_unregister(struct request_queue *q); +int blk_mq_debugfs_register_hctxs(struct request_queue *q); +void blk_mq_debugfs_unregister_hctxs(struct request_queue *q); +#else +static inline void blk_mq_debugfs_init(void) +{ +} + +int blk_mq_debugfs_register(struct request_queue *q, const char *name); +{ + return 0; +} + +void blk_mq_debugfs_unregister(struct request_queue *q) +{ +} + +int blk_mq_debugfs_register_hctxs(struct request_queue *q) +{ + return 0; +} + +void blk_mq_debugfs_unregister_hctxs(struct request_queue *q) +{ +} +#endif + extern void blk_mq_rq_timed_out(struct request *req, bool reserved); void blk_mq_release(struct request_queue *q); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 25564857f5f8..0ee283f3cffe 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -571,6 +571,11 @@ struct request_queue { struct list_head tag_set_list; struct bio_set *bio_split; +#ifdef CONFIG_DEBUG_FS + struct dentry *debugfs_dir; + struct dentry *mq_debugfs_dir; +#endif + bool mq_sysfs_init_done; }; From 9abb2ad21e8b9b7a2555411fbee225a508cf962d Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Wed, 25 Jan 2017 08:06:41 -0800 Subject: [PATCH 32/49] blk-mq: add hctx->{state,flags} to debugfs hctx->state could come in handy for bugs where the hardware queue gets stuck in the stopped state, and hctx->flags is just useful to know. Signed-off-by: Omar Sandoval Signed-off-by: Jens Axboe --- block/blk-mq-debugfs.c | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c index 01711bbf5ade..0c14511fa9e0 100644 --- a/block/blk-mq-debugfs.c +++ b/block/blk-mq-debugfs.c @@ -29,7 +29,49 @@ struct blk_mq_debugfs_attr { static struct dentry *block_debugfs_root; +static int hctx_state_show(struct seq_file *m, void *v) +{ + struct blk_mq_hw_ctx *hctx = m->private; + + seq_printf(m, "0x%lx\n", hctx->state); + return 0; +} + +static int hctx_state_open(struct inode *inode, struct file *file) +{ + return single_open(file, hctx_state_show, inode->i_private); +} + +static const struct file_operations hctx_state_fops = { + .open = hctx_state_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static int hctx_flags_show(struct seq_file *m, void *v) +{ + struct blk_mq_hw_ctx *hctx = m->private; + + seq_printf(m, "0x%lx\n", hctx->flags); + return 0; +} + +static int hctx_flags_open(struct inode *inode, struct file *file) +{ + return single_open(file, hctx_flags_show, inode->i_private); +} + +static const struct file_operations hctx_flags_fops = { + .open = hctx_flags_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = { + {"state", 0400, &hctx_state_fops}, + {"flags", 0400, &hctx_flags_fops}, }; static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = { From 950cd7e9ffdc44c340b8914126b39cc079f0c844 Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Wed, 25 Jan 2017 08:06:42 -0800 Subject: [PATCH 33/49] blk-mq: move hctx->dispatch and ctx->rq_list from sysfs to debugfs These lists are only useful for debugging; they definitely don't belong in sysfs. Putting them in debugfs also removes the limitation of a single page of output. Reviewed-by: Hannes Reinecke Signed-off-by: Omar Sandoval Signed-off-by: Jens Axboe --- block/blk-mq-debugfs.c | 106 +++++++++++++++++++++++++++++++++++++++++ block/blk-mq-sysfs.c | 57 ---------------------- 2 files changed, 106 insertions(+), 57 deletions(-) diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c index 0c14511fa9e0..1967c06d80e0 100644 --- a/block/blk-mq-debugfs.c +++ b/block/blk-mq-debugfs.c @@ -29,6 +29,20 @@ struct blk_mq_debugfs_attr { static struct dentry *block_debugfs_root; +static int blk_mq_debugfs_seq_open(struct inode *inode, struct file *file, + const struct seq_operations *ops) +{ + struct seq_file *m; + int ret; + + ret = seq_open(file, ops); + if (!ret) { + m = file->private_data; + m->private = inode->i_private; + } + return ret; +} + static int hctx_state_show(struct seq_file *m, void *v) { struct blk_mq_hw_ctx *hctx = m->private; @@ -69,12 +83,104 @@ static const struct file_operations hctx_flags_fops = { .release = single_release, }; +static int blk_mq_debugfs_rq_show(struct seq_file *m, void *v) +{ + struct request *rq = list_entry_rq(v); + + seq_printf(m, "%p\n", rq); + return 0; +} + +static void *hctx_dispatch_start(struct seq_file *m, loff_t *pos) +{ + struct blk_mq_hw_ctx *hctx = m->private; + + spin_lock(&hctx->lock); + return seq_list_start(&hctx->dispatch, *pos); +} + +static void *hctx_dispatch_next(struct seq_file *m, void *v, loff_t *pos) +{ + struct blk_mq_hw_ctx *hctx = m->private; + + return seq_list_next(v, &hctx->dispatch, pos); +} + +static void hctx_dispatch_stop(struct seq_file *m, void *v) +{ + struct blk_mq_hw_ctx *hctx = m->private; + + spin_unlock(&hctx->lock); +} + +static const struct seq_operations hctx_dispatch_seq_ops = { + .start = hctx_dispatch_start, + .next = hctx_dispatch_next, + .stop = hctx_dispatch_stop, + .show = blk_mq_debugfs_rq_show, +}; + +static int hctx_dispatch_open(struct inode *inode, struct file *file) +{ + return blk_mq_debugfs_seq_open(inode, file, &hctx_dispatch_seq_ops); +} + +static const struct file_operations hctx_dispatch_fops = { + .open = hctx_dispatch_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + +static void *ctx_rq_list_start(struct seq_file *m, loff_t *pos) +{ + struct blk_mq_ctx *ctx = m->private; + + spin_lock(&ctx->lock); + return seq_list_start(&ctx->rq_list, *pos); +} + +static void *ctx_rq_list_next(struct seq_file *m, void *v, loff_t *pos) +{ + struct blk_mq_ctx *ctx = m->private; + + return seq_list_next(v, &ctx->rq_list, pos); +} + +static void ctx_rq_list_stop(struct seq_file *m, void *v) +{ + struct blk_mq_ctx *ctx = m->private; + + spin_unlock(&ctx->lock); +} + +static const struct seq_operations ctx_rq_list_seq_ops = { + .start = ctx_rq_list_start, + .next = ctx_rq_list_next, + .stop = ctx_rq_list_stop, + .show = blk_mq_debugfs_rq_show, +}; + +static int ctx_rq_list_open(struct inode *inode, struct file *file) +{ + return blk_mq_debugfs_seq_open(inode, file, &ctx_rq_list_seq_ops); +} + +static const struct file_operations ctx_rq_list_fops = { + .open = ctx_rq_list_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = { {"state", 0400, &hctx_state_fops}, {"flags", 0400, &hctx_flags_fops}, + {"dispatch", 0400, &hctx_dispatch_fops}, }; static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = { + {"rq_list", 0400, &ctx_rq_list_fops}, }; int blk_mq_debugfs_register(struct request_queue *q, const char *name) diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c index 91b93ca1c1e0..ee3694d8c4ee 100644 --- a/block/blk-mq-sysfs.c +++ b/block/blk-mq-sysfs.c @@ -139,41 +139,6 @@ static ssize_t blk_mq_sysfs_completed_show(struct blk_mq_ctx *ctx, char *page) ctx->rq_completed[0]); } -static ssize_t sysfs_list_show(char *page, struct list_head *list, char *msg) -{ - struct request *rq; - int len = snprintf(page, PAGE_SIZE - 1, "%s:\n", msg); - - list_for_each_entry(rq, list, queuelist) { - const int rq_len = 2 * sizeof(rq) + 2; - - /* if the output will be truncated */ - if (PAGE_SIZE - 1 < len + rq_len) { - /* backspacing if it can't hold '\t...\n' */ - if (PAGE_SIZE - 1 < len + 5) - len -= rq_len; - len += snprintf(page + len, PAGE_SIZE - 1 - len, - "\t...\n"); - break; - } - len += snprintf(page + len, PAGE_SIZE - 1 - len, - "\t%p\n", rq); - } - - return len; -} - -static ssize_t blk_mq_sysfs_rq_list_show(struct blk_mq_ctx *ctx, char *page) -{ - ssize_t ret; - - spin_lock(&ctx->lock); - ret = sysfs_list_show(page, &ctx->rq_list, "CTX pending"); - spin_unlock(&ctx->lock); - - return ret; -} - static ssize_t blk_mq_hw_sysfs_poll_show(struct blk_mq_hw_ctx *hctx, char *page) { return sprintf(page, "considered=%lu, invoked=%lu, success=%lu\n", @@ -219,18 +184,6 @@ static ssize_t blk_mq_hw_sysfs_dispatched_show(struct blk_mq_hw_ctx *hctx, return page - start_page; } -static ssize_t blk_mq_hw_sysfs_rq_list_show(struct blk_mq_hw_ctx *hctx, - char *page) -{ - ssize_t ret; - - spin_lock(&hctx->lock); - ret = sysfs_list_show(page, &hctx->dispatch, "HCTX pending"); - spin_unlock(&hctx->lock); - - return ret; -} - static ssize_t blk_mq_hw_sysfs_sched_tags_show(struct blk_mq_hw_ctx *hctx, char *page) { if (hctx->sched_tags) @@ -320,16 +273,11 @@ static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_completed = { .attr = {.name = "completed", .mode = S_IRUGO }, .show = blk_mq_sysfs_completed_show, }; -static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_rq_list = { - .attr = {.name = "rq_list", .mode = S_IRUGO }, - .show = blk_mq_sysfs_rq_list_show, -}; static struct attribute *default_ctx_attrs[] = { &blk_mq_sysfs_dispatched.attr, &blk_mq_sysfs_merged.attr, &blk_mq_sysfs_completed.attr, - &blk_mq_sysfs_rq_list.attr, NULL, }; @@ -349,10 +297,6 @@ static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_active = { .attr = {.name = "active", .mode = S_IRUGO }, .show = blk_mq_hw_sysfs_active_show, }; -static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_pending = { - .attr = {.name = "pending", .mode = S_IRUGO }, - .show = blk_mq_hw_sysfs_rq_list_show, -}; static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_sched_tags = { .attr = {.name = "sched_tags", .mode = S_IRUGO }, .show = blk_mq_hw_sysfs_sched_tags_show, @@ -380,7 +324,6 @@ static struct attribute *default_hw_ctx_attrs[] = { &blk_mq_hw_sysfs_queued.attr, &blk_mq_hw_sysfs_run.attr, &blk_mq_hw_sysfs_dispatched.attr, - &blk_mq_hw_sysfs_pending.attr, &blk_mq_hw_sysfs_tags.attr, &blk_mq_hw_sysfs_sched_tags.attr, &blk_mq_hw_sysfs_cpus.attr, From 7b3938524cfbd7abd1814d879ecfcd2e2a9aa775 Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Wed, 25 Jan 2017 08:06:43 -0800 Subject: [PATCH 34/49] blk-mq: add extra request information to debugfs The request pointers by themselves aren't super useful. Reviewed-by: Hannes Reinecke Signed-off-by: Omar Sandoval Signed-off-by: Jens Axboe --- block/blk-mq-debugfs.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c index 1967c06d80e0..ee947f2f605b 100644 --- a/block/blk-mq-debugfs.c +++ b/block/blk-mq-debugfs.c @@ -87,7 +87,9 @@ static int blk_mq_debugfs_rq_show(struct seq_file *m, void *v) { struct request *rq = list_entry_rq(v); - seq_printf(m, "%p\n", rq); + seq_printf(m, "%p {.cmd_type=%u, .cmd_flags=0x%x, .rq_flags=0x%x, .tag=%d, .internal_tag=%d}\n", + rq, rq->cmd_type, rq->cmd_flags, (unsigned int)rq->rq_flags, + rq->tag, rq->internal_tag); return 0; } From 24af1ccfe12adddbe17d11801e1689791a4cc282 Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Wed, 25 Jan 2017 14:32:13 -0800 Subject: [PATCH 35/49] sbitmap: add helpers for dumping to a seq_file This is useful debugging information that will be used in the blk-mq debugfs directory. Reviewed-by: Hannes Reinecke Signed-off-by: Omar Sandoval Changed 'weight' to 'busy'. Signed-off-by: Jens Axboe --- include/linux/sbitmap.h | 30 ++++++++++++++ lib/sbitmap.c | 91 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 121 insertions(+) diff --git a/include/linux/sbitmap.h b/include/linux/sbitmap.h index f017fd6e69c4..d4e0a204c118 100644 --- a/include/linux/sbitmap.h +++ b/include/linux/sbitmap.h @@ -258,6 +258,26 @@ static inline int sbitmap_test_bit(struct sbitmap *sb, unsigned int bitnr) unsigned int sbitmap_weight(const struct sbitmap *sb); +/** + * sbitmap_show() - Dump &struct sbitmap information to a &struct seq_file. + * @sb: Bitmap to show. + * @m: struct seq_file to write to. + * + * This is intended for debugging. The format may change at any time. + */ +void sbitmap_show(struct sbitmap *sb, struct seq_file *m); + +/** + * sbitmap_bitmap_show() - Write a hex dump of a &struct sbitmap to a &struct + * seq_file. + * @sb: Bitmap to show. + * @m: struct seq_file to write to. + * + * This is intended for debugging. The output isn't guaranteed to be internally + * consistent. + */ +void sbitmap_bitmap_show(struct sbitmap *sb, struct seq_file *m); + /** * sbitmap_queue_init_node() - Initialize a &struct sbitmap_queue on a specific * memory node. @@ -370,4 +390,14 @@ static inline struct sbq_wait_state *sbq_wait_ptr(struct sbitmap_queue *sbq, */ void sbitmap_queue_wake_all(struct sbitmap_queue *sbq); +/** + * sbitmap_queue_show() - Dump &struct sbitmap_queue information to a &struct + * seq_file. + * @sbq: Bitmap queue to show. + * @m: struct seq_file to write to. + * + * This is intended for debugging. The format may change at any time. + */ +void sbitmap_queue_show(struct sbitmap_queue *sbq, struct seq_file *m); + #endif /* __LINUX_SCALE_BITMAP_H */ diff --git a/lib/sbitmap.c b/lib/sbitmap.c index 8f5c3b268c77..55e11c4b2f3b 100644 --- a/lib/sbitmap.c +++ b/lib/sbitmap.c @@ -17,6 +17,7 @@ #include #include +#include int sbitmap_init_node(struct sbitmap *sb, unsigned int depth, int shift, gfp_t flags, int node) @@ -180,6 +181,62 @@ unsigned int sbitmap_weight(const struct sbitmap *sb) } EXPORT_SYMBOL_GPL(sbitmap_weight); +void sbitmap_show(struct sbitmap *sb, struct seq_file *m) +{ + seq_printf(m, "depth=%u\n", sb->depth); + seq_printf(m, "busy=%u\n", sbitmap_weight(sb)); + seq_printf(m, "bits_per_word=%u\n", 1U << sb->shift); + seq_printf(m, "map_nr=%u\n", sb->map_nr); +} +EXPORT_SYMBOL_GPL(sbitmap_show); + +static inline void emit_byte(struct seq_file *m, unsigned int offset, u8 byte) +{ + if ((offset & 0xf) == 0) { + if (offset != 0) + seq_putc(m, '\n'); + seq_printf(m, "%08x:", offset); + } + if ((offset & 0x1) == 0) + seq_putc(m, ' '); + seq_printf(m, "%02x", byte); +} + +void sbitmap_bitmap_show(struct sbitmap *sb, struct seq_file *m) +{ + u8 byte = 0; + unsigned int byte_bits = 0; + unsigned int offset = 0; + int i; + + for (i = 0; i < sb->map_nr; i++) { + unsigned long word = READ_ONCE(sb->map[i].word); + unsigned int word_bits = READ_ONCE(sb->map[i].depth); + + while (word_bits > 0) { + unsigned int bits = min(8 - byte_bits, word_bits); + + byte |= (word & (BIT(bits) - 1)) << byte_bits; + byte_bits += bits; + if (byte_bits == 8) { + emit_byte(m, offset, byte); + byte = 0; + byte_bits = 0; + offset++; + } + word >>= bits; + word_bits -= bits; + } + } + if (byte_bits) { + emit_byte(m, offset, byte); + offset++; + } + if (offset) + seq_putc(m, '\n'); +} +EXPORT_SYMBOL_GPL(sbitmap_bitmap_show); + static unsigned int sbq_calc_wake_batch(unsigned int depth) { unsigned int wake_batch; @@ -377,3 +434,37 @@ void sbitmap_queue_wake_all(struct sbitmap_queue *sbq) } } EXPORT_SYMBOL_GPL(sbitmap_queue_wake_all); + +void sbitmap_queue_show(struct sbitmap_queue *sbq, struct seq_file *m) +{ + bool first; + int i; + + sbitmap_show(&sbq->sb, m); + + seq_puts(m, "alloc_hint={"); + first = true; + for_each_possible_cpu(i) { + if (!first) + seq_puts(m, ", "); + first = false; + seq_printf(m, "%u", *per_cpu_ptr(sbq->alloc_hint, i)); + } + seq_puts(m, "}\n"); + + seq_printf(m, "wake_batch=%u\n", sbq->wake_batch); + seq_printf(m, "wake_index=%d\n", atomic_read(&sbq->wake_index)); + + seq_puts(m, "ws={\n"); + for (i = 0; i < SBQ_WAIT_QUEUES; i++) { + struct sbq_wait_state *ws = &sbq->ws[i]; + + seq_printf(m, "\t{.wait_cnt=%d, .wait=%s},\n", + atomic_read(&ws->wait_cnt), + waitqueue_active(&ws->wait) ? "active" : "inactive"); + } + seq_puts(m, "}\n"); + + seq_printf(m, "round_robin=%d\n", sbq->round_robin); +} +EXPORT_SYMBOL_GPL(sbitmap_queue_show); From 0bfa5288a78176be8a895ce65dbbf61f63f54b96 Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Wed, 25 Jan 2017 08:06:45 -0800 Subject: [PATCH 36/49] blk-mq: export software queue pending map to debugfs This is useful for debugging problems where we've gotten stuck with requests in the software queues. Reviewed-by: Hannes Reinecke Signed-off-by: Omar Sandoval Signed-off-by: Jens Axboe --- block/blk-mq-debugfs.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c index ee947f2f605b..857bdadc6b1f 100644 --- a/block/blk-mq-debugfs.c +++ b/block/blk-mq-debugfs.c @@ -134,6 +134,26 @@ static const struct file_operations hctx_dispatch_fops = { .release = seq_release, }; +static int hctx_ctx_map_show(struct seq_file *m, void *v) +{ + struct blk_mq_hw_ctx *hctx = m->private; + + sbitmap_bitmap_show(&hctx->ctx_map, m); + return 0; +} + +static int hctx_ctx_map_open(struct inode *inode, struct file *file) +{ + return single_open(file, hctx_ctx_map_show, inode->i_private); +} + +static const struct file_operations hctx_ctx_map_fops = { + .open = hctx_ctx_map_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + static void *ctx_rq_list_start(struct seq_file *m, loff_t *pos) { struct blk_mq_ctx *ctx = m->private; @@ -179,6 +199,7 @@ static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = { {"state", 0400, &hctx_state_fops}, {"flags", 0400, &hctx_flags_fops}, {"dispatch", 0400, &hctx_dispatch_fops}, + {"ctx_map", 0400, &hctx_ctx_map_fops}, }; static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = { From d96b37c0af3e4f42928a1361d5cd9f4f8921b4a8 Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Wed, 25 Jan 2017 08:06:46 -0800 Subject: [PATCH 37/49] blk-mq: move tags and sched_tags info from sysfs to debugfs These are very tied to the blk-mq tag implementation, so exposing them to sysfs isn't a great idea. Move the debugging information to debugfs and add basic entries for the number of tags and the number of reserved tags to sysfs. Reviewed-by: Hannes Reinecke Signed-off-by: Omar Sandoval Signed-off-by: Jens Axboe --- block/blk-mq-debugfs.c | 70 ++++++++++++++++++++++++++++++++++++++++++ block/blk-mq-sysfs.c | 33 ++++++++++---------- block/blk-mq-tag.c | 27 ---------------- block/blk-mq-tag.h | 1 - 4 files changed, 86 insertions(+), 45 deletions(-) diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c index 857bdadc6b1f..9f811007cf4f 100644 --- a/block/blk-mq-debugfs.c +++ b/block/blk-mq-debugfs.c @@ -20,6 +20,7 @@ #include #include "blk-mq.h" +#include "blk-mq-tag.h" struct blk_mq_debugfs_attr { const char *name; @@ -154,6 +155,73 @@ static const struct file_operations hctx_ctx_map_fops = { .release = single_release, }; +static void blk_mq_debugfs_tags_show(struct seq_file *m, + struct blk_mq_tags *tags) +{ + seq_printf(m, "nr_tags=%u\n", tags->nr_tags); + seq_printf(m, "nr_reserved_tags=%u\n", tags->nr_reserved_tags); + seq_printf(m, "active_queues=%d\n", + atomic_read(&tags->active_queues)); + + seq_puts(m, "\nbitmap_tags:\n"); + sbitmap_queue_show(&tags->bitmap_tags, m); + + if (tags->nr_reserved_tags) { + seq_puts(m, "\nbreserved_tags:\n"); + sbitmap_queue_show(&tags->breserved_tags, m); + } +} + +static int hctx_tags_show(struct seq_file *m, void *v) +{ + struct blk_mq_hw_ctx *hctx = m->private; + struct request_queue *q = hctx->queue; + + mutex_lock(&q->sysfs_lock); + if (hctx->tags) + blk_mq_debugfs_tags_show(m, hctx->tags); + mutex_unlock(&q->sysfs_lock); + + return 0; +} + +static int hctx_tags_open(struct inode *inode, struct file *file) +{ + return single_open(file, hctx_tags_show, inode->i_private); +} + +static const struct file_operations hctx_tags_fops = { + .open = hctx_tags_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static int hctx_sched_tags_show(struct seq_file *m, void *v) +{ + struct blk_mq_hw_ctx *hctx = m->private; + struct request_queue *q = hctx->queue; + + mutex_lock(&q->sysfs_lock); + if (hctx->sched_tags) + blk_mq_debugfs_tags_show(m, hctx->sched_tags); + mutex_unlock(&q->sysfs_lock); + + return 0; +} + +static int hctx_sched_tags_open(struct inode *inode, struct file *file) +{ + return single_open(file, hctx_sched_tags_show, inode->i_private); +} + +static const struct file_operations hctx_sched_tags_fops = { + .open = hctx_sched_tags_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + static void *ctx_rq_list_start(struct seq_file *m, loff_t *pos) { struct blk_mq_ctx *ctx = m->private; @@ -200,6 +268,8 @@ static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = { {"flags", 0400, &hctx_flags_fops}, {"dispatch", 0400, &hctx_dispatch_fops}, {"ctx_map", 0400, &hctx_ctx_map_fops}, + {"tags", 0400, &hctx_tags_fops}, + {"sched_tags", 0400, &hctx_sched_tags_fops}, }; static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = { diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c index ee3694d8c4ee..a0ae1f536ed0 100644 --- a/block/blk-mq-sysfs.c +++ b/block/blk-mq-sysfs.c @@ -184,17 +184,16 @@ static ssize_t blk_mq_hw_sysfs_dispatched_show(struct blk_mq_hw_ctx *hctx, return page - start_page; } -static ssize_t blk_mq_hw_sysfs_sched_tags_show(struct blk_mq_hw_ctx *hctx, char *page) +static ssize_t blk_mq_hw_sysfs_nr_tags_show(struct blk_mq_hw_ctx *hctx, + char *page) { - if (hctx->sched_tags) - return blk_mq_tag_sysfs_show(hctx->sched_tags, page); - - return 0; + return sprintf(page, "%u\n", hctx->tags->nr_tags); } -static ssize_t blk_mq_hw_sysfs_tags_show(struct blk_mq_hw_ctx *hctx, char *page) +static ssize_t blk_mq_hw_sysfs_nr_reserved_tags_show(struct blk_mq_hw_ctx *hctx, + char *page) { - return blk_mq_tag_sysfs_show(hctx->tags, page); + return sprintf(page, "%u\n", hctx->tags->nr_reserved_tags); } static ssize_t blk_mq_hw_sysfs_active_show(struct blk_mq_hw_ctx *hctx, char *page) @@ -293,18 +292,18 @@ static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_dispatched = { .attr = {.name = "dispatched", .mode = S_IRUGO }, .show = blk_mq_hw_sysfs_dispatched_show, }; +static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_tags = { + .attr = {.name = "nr_tags", .mode = S_IRUGO }, + .show = blk_mq_hw_sysfs_nr_tags_show, +}; +static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_reserved_tags = { + .attr = {.name = "nr_reserved_tags", .mode = S_IRUGO }, + .show = blk_mq_hw_sysfs_nr_reserved_tags_show, +}; static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_active = { .attr = {.name = "active", .mode = S_IRUGO }, .show = blk_mq_hw_sysfs_active_show, }; -static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_sched_tags = { - .attr = {.name = "sched_tags", .mode = S_IRUGO }, - .show = blk_mq_hw_sysfs_sched_tags_show, -}; -static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_tags = { - .attr = {.name = "tags", .mode = S_IRUGO }, - .show = blk_mq_hw_sysfs_tags_show, -}; static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_cpus = { .attr = {.name = "cpu_list", .mode = S_IRUGO }, .show = blk_mq_hw_sysfs_cpus_show, @@ -324,8 +323,8 @@ static struct attribute *default_hw_ctx_attrs[] = { &blk_mq_hw_sysfs_queued.attr, &blk_mq_hw_sysfs_run.attr, &blk_mq_hw_sysfs_dispatched.attr, - &blk_mq_hw_sysfs_tags.attr, - &blk_mq_hw_sysfs_sched_tags.attr, + &blk_mq_hw_sysfs_nr_tags.attr, + &blk_mq_hw_sysfs_nr_reserved_tags.attr, &blk_mq_hw_sysfs_cpus.attr, &blk_mq_hw_sysfs_active.attr, &blk_mq_hw_sysfs_poll.attr, diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index 1b156ca79af6..f8de2dbbb29f 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -329,11 +329,6 @@ void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn, } -static unsigned int bt_unused_tags(const struct sbitmap_queue *bt) -{ - return bt->sb.depth - sbitmap_weight(&bt->sb); -} - static int bt_alloc(struct sbitmap_queue *bt, unsigned int depth, bool round_robin, int node) { @@ -469,25 +464,3 @@ u32 blk_mq_unique_tag(struct request *rq) (rq->tag & BLK_MQ_UNIQUE_TAG_MASK); } EXPORT_SYMBOL(blk_mq_unique_tag); - -ssize_t blk_mq_tag_sysfs_show(struct blk_mq_tags *tags, char *page) -{ - char *orig_page = page; - unsigned int free, res; - - if (!tags) - return 0; - - page += sprintf(page, "nr_tags=%u, reserved_tags=%u, " - "bits_per_word=%u\n", - tags->nr_tags, tags->nr_reserved_tags, - 1U << tags->bitmap_tags.sb.shift); - - free = bt_unused_tags(&tags->bitmap_tags); - res = bt_unused_tags(&tags->breserved_tags); - - page += sprintf(page, "nr_free=%u, nr_reserved=%u\n", free, res); - page += sprintf(page, "active_queues=%u\n", atomic_read(&tags->active_queues)); - - return page - orig_page; -} diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h index ac22878462e7..63497423c5cd 100644 --- a/block/blk-mq-tag.h +++ b/block/blk-mq-tag.h @@ -28,7 +28,6 @@ extern unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data); extern void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, struct blk_mq_tags *tags, struct blk_mq_ctx *ctx, unsigned int tag); extern bool blk_mq_has_free_tags(struct blk_mq_tags *tags); -extern ssize_t blk_mq_tag_sysfs_show(struct blk_mq_tags *tags, char *page); extern int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx, struct blk_mq_tags **tags, unsigned int depth, bool can_grow); From d7e3621ad1e48f08dc14c34e353af69f7c35cb20 Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Wed, 25 Jan 2017 08:06:47 -0800 Subject: [PATCH 38/49] blk-mq: add tags and sched_tags bitmaps to debugfs These can be used to debug issues like tag leaks and stuck requests. Reviewed-by: Hannes Reinecke Signed-off-by: Omar Sandoval Signed-off-by: Jens Axboe --- block/blk-mq-debugfs.c | 50 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c index 9f811007cf4f..9b87b15619f1 100644 --- a/block/blk-mq-debugfs.c +++ b/block/blk-mq-debugfs.c @@ -197,6 +197,30 @@ static const struct file_operations hctx_tags_fops = { .release = single_release, }; +static int hctx_tags_bitmap_show(struct seq_file *m, void *v) +{ + struct blk_mq_hw_ctx *hctx = m->private; + struct request_queue *q = hctx->queue; + + mutex_lock(&q->sysfs_lock); + if (hctx->tags) + sbitmap_bitmap_show(&hctx->tags->bitmap_tags.sb, m); + mutex_unlock(&q->sysfs_lock); + return 0; +} + +static int hctx_tags_bitmap_open(struct inode *inode, struct file *file) +{ + return single_open(file, hctx_tags_bitmap_show, inode->i_private); +} + +static const struct file_operations hctx_tags_bitmap_fops = { + .open = hctx_tags_bitmap_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + static int hctx_sched_tags_show(struct seq_file *m, void *v) { struct blk_mq_hw_ctx *hctx = m->private; @@ -222,6 +246,30 @@ static const struct file_operations hctx_sched_tags_fops = { .release = single_release, }; +static int hctx_sched_tags_bitmap_show(struct seq_file *m, void *v) +{ + struct blk_mq_hw_ctx *hctx = m->private; + struct request_queue *q = hctx->queue; + + mutex_lock(&q->sysfs_lock); + if (hctx->sched_tags) + sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags.sb, m); + mutex_unlock(&q->sysfs_lock); + return 0; +} + +static int hctx_sched_tags_bitmap_open(struct inode *inode, struct file *file) +{ + return single_open(file, hctx_sched_tags_bitmap_show, inode->i_private); +} + +static const struct file_operations hctx_sched_tags_bitmap_fops = { + .open = hctx_sched_tags_bitmap_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + static void *ctx_rq_list_start(struct seq_file *m, loff_t *pos) { struct blk_mq_ctx *ctx = m->private; @@ -269,7 +317,9 @@ static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = { {"dispatch", 0400, &hctx_dispatch_fops}, {"ctx_map", 0400, &hctx_ctx_map_fops}, {"tags", 0400, &hctx_tags_fops}, + {"tags_bitmap", 0400, &hctx_tags_bitmap_fops}, {"sched_tags", 0400, &hctx_sched_tags_fops}, + {"sched_tags_bitmap", 0400, &hctx_sched_tags_bitmap_fops}, }; static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = { From be21547318b2c7d9988237b106cc63767b86eae4 Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Wed, 25 Jan 2017 08:06:48 -0800 Subject: [PATCH 39/49] blk-mq: move hctx io_poll, stats, and dispatched from sysfs to debugfs These statistics _might_ be useful to userspace, but it's better not to commit to an ABI for these yet. Also, the dispatched file in sysfs couldn't be cleared, so make it clearable like the others in debugfs. Reviewed-by: Hannes Reinecke Signed-off-by: Omar Sandoval Signed-off-by: Jens Axboe --- block/blk-mq-debugfs.c | 132 +++++++++++++++++++++++++++++++++++++++++ block/blk-mq-sysfs.c | 92 ---------------------------- 2 files changed, 132 insertions(+), 92 deletions(-) diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c index 9b87b15619f1..28ca56dd2c4e 100644 --- a/block/blk-mq-debugfs.c +++ b/block/blk-mq-debugfs.c @@ -270,6 +270,135 @@ static const struct file_operations hctx_sched_tags_bitmap_fops = { .release = single_release, }; +static int hctx_io_poll_show(struct seq_file *m, void *v) +{ + struct blk_mq_hw_ctx *hctx = m->private; + + seq_printf(m, "considered=%lu\n", hctx->poll_considered); + seq_printf(m, "invoked=%lu\n", hctx->poll_invoked); + seq_printf(m, "success=%lu\n", hctx->poll_success); + return 0; +} + +static int hctx_io_poll_open(struct inode *inode, struct file *file) +{ + return single_open(file, hctx_io_poll_show, inode->i_private); +} + +static ssize_t hctx_io_poll_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct seq_file *m = file->private_data; + struct blk_mq_hw_ctx *hctx = m->private; + + hctx->poll_considered = hctx->poll_invoked = hctx->poll_success = 0; + return count; +} + +static const struct file_operations hctx_io_poll_fops = { + .open = hctx_io_poll_open, + .read = seq_read, + .write = hctx_io_poll_write, + .llseek = seq_lseek, + .release = single_release, +}; + +static void print_stat(struct seq_file *m, struct blk_rq_stat *stat) +{ + seq_printf(m, "samples=%d, mean=%lld, min=%llu, max=%llu", + stat->nr_samples, stat->mean, stat->min, stat->max); +} + +static int hctx_stats_show(struct seq_file *m, void *v) +{ + struct blk_mq_hw_ctx *hctx = m->private; + struct blk_rq_stat stat[2]; + + blk_stat_init(&stat[BLK_STAT_READ]); + blk_stat_init(&stat[BLK_STAT_WRITE]); + + blk_hctx_stat_get(hctx, stat); + + seq_puts(m, "read: "); + print_stat(m, &stat[BLK_STAT_READ]); + seq_puts(m, "\n"); + + seq_puts(m, "write: "); + print_stat(m, &stat[BLK_STAT_WRITE]); + seq_puts(m, "\n"); + return 0; +} + +static int hctx_stats_open(struct inode *inode, struct file *file) +{ + return single_open(file, hctx_stats_show, inode->i_private); +} + +static ssize_t hctx_stats_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct seq_file *m = file->private_data; + struct blk_mq_hw_ctx *hctx = m->private; + struct blk_mq_ctx *ctx; + int i; + + hctx_for_each_ctx(hctx, ctx, i) { + blk_stat_init(&ctx->stat[BLK_STAT_READ]); + blk_stat_init(&ctx->stat[BLK_STAT_WRITE]); + } + return count; +} + +static const struct file_operations hctx_stats_fops = { + .open = hctx_stats_open, + .read = seq_read, + .write = hctx_stats_write, + .llseek = seq_lseek, + .release = single_release, +}; + +static int hctx_dispatched_show(struct seq_file *m, void *v) +{ + struct blk_mq_hw_ctx *hctx = m->private; + int i; + + seq_printf(m, "%8u\t%lu\n", 0U, hctx->dispatched[0]); + + for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER - 1; i++) { + unsigned int d = 1U << (i - 1); + + seq_printf(m, "%8u\t%lu\n", d, hctx->dispatched[i]); + } + + seq_printf(m, "%8u+\t%lu\n", 1U << (i - 1), hctx->dispatched[i]); + return 0; +} + +static int hctx_dispatched_open(struct inode *inode, struct file *file) +{ + return single_open(file, hctx_dispatched_show, inode->i_private); +} + +static ssize_t hctx_dispatched_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct seq_file *m = file->private_data; + struct blk_mq_hw_ctx *hctx = m->private; + int i; + + for (i = 0; i < BLK_MQ_MAX_DISPATCH_ORDER; i++) + hctx->dispatched[i] = 0; + return count; +} + +static const struct file_operations hctx_dispatched_fops = { + .open = hctx_dispatched_open, + .read = seq_read, + .write = hctx_dispatched_write, + .llseek = seq_lseek, + .release = single_release, +}; + static void *ctx_rq_list_start(struct seq_file *m, loff_t *pos) { struct blk_mq_ctx *ctx = m->private; @@ -320,6 +449,9 @@ static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = { {"tags_bitmap", 0400, &hctx_tags_bitmap_fops}, {"sched_tags", 0400, &hctx_sched_tags_fops}, {"sched_tags_bitmap", 0400, &hctx_sched_tags_bitmap_fops}, + {"io_poll", 0600, &hctx_io_poll_fops}, + {"stats", 0600, &hctx_stats_fops}, + {"dispatched", 0600, &hctx_dispatched_fops}, }; static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = { diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c index a0ae1f536ed0..f505da2c542e 100644 --- a/block/blk-mq-sysfs.c +++ b/block/blk-mq-sysfs.c @@ -139,21 +139,6 @@ static ssize_t blk_mq_sysfs_completed_show(struct blk_mq_ctx *ctx, char *page) ctx->rq_completed[0]); } -static ssize_t blk_mq_hw_sysfs_poll_show(struct blk_mq_hw_ctx *hctx, char *page) -{ - return sprintf(page, "considered=%lu, invoked=%lu, success=%lu\n", - hctx->poll_considered, hctx->poll_invoked, - hctx->poll_success); -} - -static ssize_t blk_mq_hw_sysfs_poll_store(struct blk_mq_hw_ctx *hctx, - const char *page, size_t size) -{ - hctx->poll_considered = hctx->poll_invoked = hctx->poll_success = 0; - - return size; -} - static ssize_t blk_mq_hw_sysfs_queued_show(struct blk_mq_hw_ctx *hctx, char *page) { @@ -165,25 +150,6 @@ static ssize_t blk_mq_hw_sysfs_run_show(struct blk_mq_hw_ctx *hctx, char *page) return sprintf(page, "%lu\n", hctx->run); } -static ssize_t blk_mq_hw_sysfs_dispatched_show(struct blk_mq_hw_ctx *hctx, - char *page) -{ - char *start_page = page; - int i; - - page += sprintf(page, "%8u\t%lu\n", 0U, hctx->dispatched[0]); - - for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER - 1; i++) { - unsigned int d = 1U << (i - 1); - - page += sprintf(page, "%8u\t%lu\n", d, hctx->dispatched[i]); - } - - page += sprintf(page, "%8u+\t%lu\n", 1U << (i - 1), - hctx->dispatched[i]); - return page - start_page; -} - static ssize_t blk_mq_hw_sysfs_nr_tags_show(struct blk_mq_hw_ctx *hctx, char *page) { @@ -219,47 +185,6 @@ static ssize_t blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx *hctx, char *page) return ret; } -static void blk_mq_stat_clear(struct blk_mq_hw_ctx *hctx) -{ - struct blk_mq_ctx *ctx; - unsigned int i; - - hctx_for_each_ctx(hctx, ctx, i) { - blk_stat_init(&ctx->stat[BLK_STAT_READ]); - blk_stat_init(&ctx->stat[BLK_STAT_WRITE]); - } -} - -static ssize_t blk_mq_hw_sysfs_stat_store(struct blk_mq_hw_ctx *hctx, - const char *page, size_t count) -{ - blk_mq_stat_clear(hctx); - return count; -} - -static ssize_t print_stat(char *page, struct blk_rq_stat *stat, const char *pre) -{ - return sprintf(page, "%s samples=%llu, mean=%lld, min=%lld, max=%lld\n", - pre, (long long) stat->nr_samples, - (long long) stat->mean, (long long) stat->min, - (long long) stat->max); -} - -static ssize_t blk_mq_hw_sysfs_stat_show(struct blk_mq_hw_ctx *hctx, char *page) -{ - struct blk_rq_stat stat[2]; - ssize_t ret; - - blk_stat_init(&stat[BLK_STAT_READ]); - blk_stat_init(&stat[BLK_STAT_WRITE]); - - blk_hctx_stat_get(hctx, stat); - - ret = print_stat(page, &stat[BLK_STAT_READ], "read :"); - ret += print_stat(page + ret, &stat[BLK_STAT_WRITE], "write:"); - return ret; -} - static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_dispatched = { .attr = {.name = "dispatched", .mode = S_IRUGO }, .show = blk_mq_sysfs_dispatched_show, @@ -288,10 +213,6 @@ static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_run = { .attr = {.name = "run", .mode = S_IRUGO }, .show = blk_mq_hw_sysfs_run_show, }; -static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_dispatched = { - .attr = {.name = "dispatched", .mode = S_IRUGO }, - .show = blk_mq_hw_sysfs_dispatched_show, -}; static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_tags = { .attr = {.name = "nr_tags", .mode = S_IRUGO }, .show = blk_mq_hw_sysfs_nr_tags_show, @@ -308,27 +229,14 @@ static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_cpus = { .attr = {.name = "cpu_list", .mode = S_IRUGO }, .show = blk_mq_hw_sysfs_cpus_show, }; -static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_poll = { - .attr = {.name = "io_poll", .mode = S_IWUSR | S_IRUGO }, - .show = blk_mq_hw_sysfs_poll_show, - .store = blk_mq_hw_sysfs_poll_store, -}; -static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_stat = { - .attr = {.name = "stats", .mode = S_IRUGO | S_IWUSR }, - .show = blk_mq_hw_sysfs_stat_show, - .store = blk_mq_hw_sysfs_stat_store, -}; static struct attribute *default_hw_ctx_attrs[] = { &blk_mq_hw_sysfs_queued.attr, &blk_mq_hw_sysfs_run.attr, - &blk_mq_hw_sysfs_dispatched.attr, &blk_mq_hw_sysfs_nr_tags.attr, &blk_mq_hw_sysfs_nr_reserved_tags.attr, &blk_mq_hw_sysfs_cpus.attr, &blk_mq_hw_sysfs_active.attr, - &blk_mq_hw_sysfs_poll.attr, - &blk_mq_hw_sysfs_stat.attr, NULL, }; From 4a46f05ebf9921dcba35770106e42574d323d6dd Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Wed, 25 Jan 2017 08:06:49 -0800 Subject: [PATCH 40/49] blk-mq: move hctx and ctx counters from sysfs to debugfs These counters aren't as out-of-place in sysfs as the other stuff, but debugfs is a slightly better home for them. Reviewed-by: Hannes Reinecke Signed-off-by: Omar Sandoval Signed-off-by: Jens Axboe --- block/blk-mq-debugfs.c | 181 +++++++++++++++++++++++++++++++++++++++++ block/blk-mq-sysfs.c | 64 --------------- 2 files changed, 181 insertions(+), 64 deletions(-) diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c index 28ca56dd2c4e..5cd2b435a9f5 100644 --- a/block/blk-mq-debugfs.c +++ b/block/blk-mq-debugfs.c @@ -399,6 +399,88 @@ static const struct file_operations hctx_dispatched_fops = { .release = single_release, }; +static int hctx_queued_show(struct seq_file *m, void *v) +{ + struct blk_mq_hw_ctx *hctx = m->private; + + seq_printf(m, "%lu\n", hctx->queued); + return 0; +} + +static int hctx_queued_open(struct inode *inode, struct file *file) +{ + return single_open(file, hctx_queued_show, inode->i_private); +} + +static ssize_t hctx_queued_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct seq_file *m = file->private_data; + struct blk_mq_hw_ctx *hctx = m->private; + + hctx->queued = 0; + return count; +} + +static const struct file_operations hctx_queued_fops = { + .open = hctx_queued_open, + .read = seq_read, + .write = hctx_queued_write, + .llseek = seq_lseek, + .release = single_release, +}; + +static int hctx_run_show(struct seq_file *m, void *v) +{ + struct blk_mq_hw_ctx *hctx = m->private; + + seq_printf(m, "%lu\n", hctx->run); + return 0; +} + +static int hctx_run_open(struct inode *inode, struct file *file) +{ + return single_open(file, hctx_run_show, inode->i_private); +} + +static ssize_t hctx_run_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct seq_file *m = file->private_data; + struct blk_mq_hw_ctx *hctx = m->private; + + hctx->run = 0; + return count; +} + +static const struct file_operations hctx_run_fops = { + .open = hctx_run_open, + .read = seq_read, + .write = hctx_run_write, + .llseek = seq_lseek, + .release = single_release, +}; + +static int hctx_active_show(struct seq_file *m, void *v) +{ + struct blk_mq_hw_ctx *hctx = m->private; + + seq_printf(m, "%d\n", atomic_read(&hctx->nr_active)); + return 0; +} + +static int hctx_active_open(struct inode *inode, struct file *file) +{ + return single_open(file, hctx_active_show, inode->i_private); +} + +static const struct file_operations hctx_active_fops = { + .open = hctx_active_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + static void *ctx_rq_list_start(struct seq_file *m, loff_t *pos) { struct blk_mq_ctx *ctx = m->private; @@ -440,6 +522,99 @@ static const struct file_operations ctx_rq_list_fops = { .release = seq_release, }; +static int ctx_dispatched_show(struct seq_file *m, void *v) +{ + struct blk_mq_ctx *ctx = m->private; + + seq_printf(m, "%lu %lu\n", ctx->rq_dispatched[1], ctx->rq_dispatched[0]); + return 0; +} + +static int ctx_dispatched_open(struct inode *inode, struct file *file) +{ + return single_open(file, ctx_dispatched_show, inode->i_private); +} + +static ssize_t ctx_dispatched_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct seq_file *m = file->private_data; + struct blk_mq_ctx *ctx = m->private; + + ctx->rq_dispatched[0] = ctx->rq_dispatched[1] = 0; + return count; +} + +static const struct file_operations ctx_dispatched_fops = { + .open = ctx_dispatched_open, + .read = seq_read, + .write = ctx_dispatched_write, + .llseek = seq_lseek, + .release = single_release, +}; + +static int ctx_merged_show(struct seq_file *m, void *v) +{ + struct blk_mq_ctx *ctx = m->private; + + seq_printf(m, "%lu\n", ctx->rq_merged); + return 0; +} + +static int ctx_merged_open(struct inode *inode, struct file *file) +{ + return single_open(file, ctx_merged_show, inode->i_private); +} + +static ssize_t ctx_merged_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct seq_file *m = file->private_data; + struct blk_mq_ctx *ctx = m->private; + + ctx->rq_merged = 0; + return count; +} + +static const struct file_operations ctx_merged_fops = { + .open = ctx_merged_open, + .read = seq_read, + .write = ctx_merged_write, + .llseek = seq_lseek, + .release = single_release, +}; + +static int ctx_completed_show(struct seq_file *m, void *v) +{ + struct blk_mq_ctx *ctx = m->private; + + seq_printf(m, "%lu %lu\n", ctx->rq_completed[1], ctx->rq_completed[0]); + return 0; +} + +static int ctx_completed_open(struct inode *inode, struct file *file) +{ + return single_open(file, ctx_completed_show, inode->i_private); +} + +static ssize_t ctx_completed_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct seq_file *m = file->private_data; + struct blk_mq_ctx *ctx = m->private; + + ctx->rq_completed[0] = ctx->rq_completed[1] = 0; + return count; +} + +static const struct file_operations ctx_completed_fops = { + .open = ctx_completed_open, + .read = seq_read, + .write = ctx_completed_write, + .llseek = seq_lseek, + .release = single_release, +}; + static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = { {"state", 0400, &hctx_state_fops}, {"flags", 0400, &hctx_flags_fops}, @@ -452,10 +627,16 @@ static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = { {"io_poll", 0600, &hctx_io_poll_fops}, {"stats", 0600, &hctx_stats_fops}, {"dispatched", 0600, &hctx_dispatched_fops}, + {"queued", 0600, &hctx_queued_fops}, + {"run", 0600, &hctx_run_fops}, + {"active", 0400, &hctx_active_fops}, }; static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = { {"rq_list", 0400, &ctx_rq_list_fops}, + {"dispatched", 0600, &ctx_dispatched_fops}, + {"merged", 0600, &ctx_merged_fops}, + {"completed", 0600, &ctx_completed_fops}, }; int blk_mq_debugfs_register(struct request_queue *q, const char *name) diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c index f505da2c542e..308b3f4fc310 100644 --- a/block/blk-mq-sysfs.c +++ b/block/blk-mq-sysfs.c @@ -122,34 +122,6 @@ static ssize_t blk_mq_hw_sysfs_store(struct kobject *kobj, return res; } -static ssize_t blk_mq_sysfs_dispatched_show(struct blk_mq_ctx *ctx, char *page) -{ - return sprintf(page, "%lu %lu\n", ctx->rq_dispatched[1], - ctx->rq_dispatched[0]); -} - -static ssize_t blk_mq_sysfs_merged_show(struct blk_mq_ctx *ctx, char *page) -{ - return sprintf(page, "%lu\n", ctx->rq_merged); -} - -static ssize_t blk_mq_sysfs_completed_show(struct blk_mq_ctx *ctx, char *page) -{ - return sprintf(page, "%lu %lu\n", ctx->rq_completed[1], - ctx->rq_completed[0]); -} - -static ssize_t blk_mq_hw_sysfs_queued_show(struct blk_mq_hw_ctx *hctx, - char *page) -{ - return sprintf(page, "%lu\n", hctx->queued); -} - -static ssize_t blk_mq_hw_sysfs_run_show(struct blk_mq_hw_ctx *hctx, char *page) -{ - return sprintf(page, "%lu\n", hctx->run); -} - static ssize_t blk_mq_hw_sysfs_nr_tags_show(struct blk_mq_hw_ctx *hctx, char *page) { @@ -162,11 +134,6 @@ static ssize_t blk_mq_hw_sysfs_nr_reserved_tags_show(struct blk_mq_hw_ctx *hctx, return sprintf(page, "%u\n", hctx->tags->nr_reserved_tags); } -static ssize_t blk_mq_hw_sysfs_active_show(struct blk_mq_hw_ctx *hctx, char *page) -{ - return sprintf(page, "%u\n", atomic_read(&hctx->nr_active)); -} - static ssize_t blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx *hctx, char *page) { unsigned int i, first = 1; @@ -185,34 +152,10 @@ static ssize_t blk_mq_hw_sysfs_cpus_show(struct blk_mq_hw_ctx *hctx, char *page) return ret; } -static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_dispatched = { - .attr = {.name = "dispatched", .mode = S_IRUGO }, - .show = blk_mq_sysfs_dispatched_show, -}; -static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_merged = { - .attr = {.name = "merged", .mode = S_IRUGO }, - .show = blk_mq_sysfs_merged_show, -}; -static struct blk_mq_ctx_sysfs_entry blk_mq_sysfs_completed = { - .attr = {.name = "completed", .mode = S_IRUGO }, - .show = blk_mq_sysfs_completed_show, -}; - static struct attribute *default_ctx_attrs[] = { - &blk_mq_sysfs_dispatched.attr, - &blk_mq_sysfs_merged.attr, - &blk_mq_sysfs_completed.attr, NULL, }; -static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_queued = { - .attr = {.name = "queued", .mode = S_IRUGO }, - .show = blk_mq_hw_sysfs_queued_show, -}; -static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_run = { - .attr = {.name = "run", .mode = S_IRUGO }, - .show = blk_mq_hw_sysfs_run_show, -}; static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_tags = { .attr = {.name = "nr_tags", .mode = S_IRUGO }, .show = blk_mq_hw_sysfs_nr_tags_show, @@ -221,22 +164,15 @@ static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_nr_reserved_tags = { .attr = {.name = "nr_reserved_tags", .mode = S_IRUGO }, .show = blk_mq_hw_sysfs_nr_reserved_tags_show, }; -static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_active = { - .attr = {.name = "active", .mode = S_IRUGO }, - .show = blk_mq_hw_sysfs_active_show, -}; static struct blk_mq_hw_ctx_sysfs_entry blk_mq_hw_sysfs_cpus = { .attr = {.name = "cpu_list", .mode = S_IRUGO }, .show = blk_mq_hw_sysfs_cpus_show, }; static struct attribute *default_hw_ctx_attrs[] = { - &blk_mq_hw_sysfs_queued.attr, - &blk_mq_hw_sysfs_run.attr, &blk_mq_hw_sysfs_nr_tags.attr, &blk_mq_hw_sysfs_nr_reserved_tags.attr, &blk_mq_hw_sysfs_cpus.attr, - &blk_mq_hw_sysfs_active.attr, NULL, }; From 0abad774124351ba211b9053786ebd5a5a722d53 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 26 Jan 2017 12:28:10 -0700 Subject: [PATCH 41/49] blk-mq: improve scheduler queue sync/async running We'll use the same criteria for whether we need to run the queue sync or async when we have a scheduler, as we do without one. Signed-off-by: Jens Axboe Reviewed-by: Omar Sandoval Tested-by: Hannes Reinecke --- block/blk-mq.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index ede835c2b08b..1f948d5c2715 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1476,7 +1476,8 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) if (q->elevator) { blk_mq_put_ctx(data.ctx); blk_mq_bio_to_request(rq, bio); - blk_mq_sched_insert_request(rq, false, true, true); + blk_mq_sched_insert_request(rq, false, true, + !is_sync || is_flush_fua); goto done; } if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) { @@ -1585,7 +1586,8 @@ static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio) if (q->elevator) { blk_mq_put_ctx(data.ctx); blk_mq_bio_to_request(rq, bio); - blk_mq_sched_insert_request(rq, false, true, true); + blk_mq_sched_insert_request(rq, false, true, + !is_sync || is_flush_fua); goto done; } if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) { From 3c782d67c16889d753a79a8da5422c583d7cfd51 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 26 Jan 2017 12:50:36 -0700 Subject: [PATCH 42/49] blk-mq: fix potential race in queue restart and driver tag allocation Once we mark the queue as needing a restart, re-check if we can get a driver tag. This fixes a theoretical issue where the needed IO completes _after_ blk_mq_get_driver_tag() fails, but before we manage to set the restart bit. Signed-off-by: Jens Axboe Reviewed-by: Omar Sandoval Tested-by: Hannes Reinecke --- block/blk-mq.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 1f948d5c2715..fd80101c7591 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -928,8 +928,16 @@ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list) if (!blk_mq_get_driver_tag(rq, &hctx, false)) { if (!queued && reorder_tags_to_front(list)) continue; + + /* + * We failed getting a driver tag. Mark the queue(s) + * as needing a restart. Retry getting a tag again, + * in case the needed IO completed right before we + * marked the queue as needing a restart. + */ blk_mq_sched_mark_restart(hctx); - break; + if (!blk_mq_get_driver_tag(rq, &hctx, false)) + break; } list_del_init(&rq->queuelist); From 99cf1dc580f0766825395aae4f60ec1d8438f011 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 26 Jan 2017 12:32:32 -0700 Subject: [PATCH 43/49] blk-mq: release driver tag on a requeue event We don't want to hold on to this resource when we have a scheduler attached. Signed-off-by: Jens Axboe Reviewed-by: Omar Sandoval Tested-by: Hannes Reinecke --- block/blk-mq.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/block/blk-mq.c b/block/blk-mq.c index fd80101c7591..711883384585 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -879,6 +879,21 @@ done: return false; } +static void blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx, + struct request *rq) +{ + if (rq->tag == -1 || rq->internal_tag == -1) + return; + + blk_mq_put_tag(hctx, hctx->tags, rq->mq_ctx, rq->tag); + rq->tag = -1; + + if (rq->rq_flags & RQF_MQ_INFLIGHT) { + rq->rq_flags &= ~RQF_MQ_INFLIGHT; + atomic_dec(&hctx->nr_active); + } +} + /* * If we fail getting a driver tag because all the driver tags are already * assigned and on the dispatch list, BUT the first entry does not have a @@ -951,6 +966,7 @@ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list) queued++; break; case BLK_MQ_RQ_QUEUE_BUSY: + blk_mq_put_driver_tag(hctx, rq); list_add(&rq->queuelist, list); __blk_mq_requeue_request(rq); break; From 50e1dab86aa2c10cbca2f754aae9542169403141 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 26 Jan 2017 14:42:34 -0700 Subject: [PATCH 44/49] blk-mq-sched: fix starvation for multiple hardware queues and shared tags If we have both multiple hardware queues and shared tag map between devices, we need to ensure that we propagate the hardware queue restart bit higher up. This is because we can get into a situation where we don't have any IO pending on a hardware queue, yet we fail getting a tag to start new IO. If that happens, it's not enough to mark the hardware queue as needing a restart, we need to bubble that up to the higher level queue as well. Signed-off-by: Jens Axboe Reviewed-by: Omar Sandoval Tested-by: Hannes Reinecke --- block/blk-mq-sched.c | 28 ++++++++++++++++++++++++++++ block/blk-mq-sched.h | 15 +++++++++------ block/blk-mq.c | 3 ++- block/blk-mq.h | 1 + include/linux/blkdev.h | 1 + 5 files changed, 41 insertions(+), 7 deletions(-) diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index 4cee060a292d..fcc0e893d687 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -301,6 +301,34 @@ bool blk_mq_sched_bypass_insert(struct blk_mq_hw_ctx *hctx, struct request *rq) } EXPORT_SYMBOL_GPL(blk_mq_sched_bypass_insert); +static void blk_mq_sched_restart_hctx(struct blk_mq_hw_ctx *hctx) +{ + if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state)) { + clear_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state); + if (blk_mq_hctx_has_pending(hctx)) + blk_mq_run_hw_queue(hctx, true); + } +} + +void blk_mq_sched_restart_queues(struct blk_mq_hw_ctx *hctx) +{ + unsigned int i; + + if (!(hctx->flags & BLK_MQ_F_TAG_SHARED)) + blk_mq_sched_restart_hctx(hctx); + else { + struct request_queue *q = hctx->queue; + + if (!test_bit(QUEUE_FLAG_RESTART, &q->queue_flags)) + return; + + clear_bit(QUEUE_FLAG_RESTART, &q->queue_flags); + + queue_for_each_hw_ctx(q, hctx, i) + blk_mq_sched_restart_hctx(hctx); + } +} + static void blk_mq_sched_free_tags(struct blk_mq_tag_set *set, struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx) diff --git a/block/blk-mq-sched.h b/block/blk-mq-sched.h index 6b465bc7014c..becbc7840364 100644 --- a/block/blk-mq-sched.h +++ b/block/blk-mq-sched.h @@ -19,6 +19,7 @@ bool blk_mq_sched_bypass_insert(struct blk_mq_hw_ctx *hctx, struct request *rq); bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio); bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio); bool blk_mq_sched_try_insert_merge(struct request_queue *q, struct request *rq); +void blk_mq_sched_restart_queues(struct blk_mq_hw_ctx *hctx); void blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx); void blk_mq_sched_move_to_dispatch(struct blk_mq_hw_ctx *hctx, @@ -123,11 +124,6 @@ blk_mq_sched_completed_request(struct blk_mq_hw_ctx *hctx, struct request *rq) BUG_ON(rq->internal_tag == -1); blk_mq_put_tag(hctx, hctx->sched_tags, rq->mq_ctx, rq->internal_tag); - - if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state)) { - clear_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state); - blk_mq_run_hw_queue(hctx, true); - } } static inline void blk_mq_sched_started_request(struct request *rq) @@ -160,8 +156,15 @@ static inline bool blk_mq_sched_has_work(struct blk_mq_hw_ctx *hctx) static inline void blk_mq_sched_mark_restart(struct blk_mq_hw_ctx *hctx) { - if (!test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state)) + if (!test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state)) { set_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state); + if (hctx->flags & BLK_MQ_F_TAG_SHARED) { + struct request_queue *q = hctx->queue; + + if (!test_bit(QUEUE_FLAG_RESTART, &q->queue_flags)) + set_bit(QUEUE_FLAG_RESTART, &q->queue_flags); + } + } } static inline bool blk_mq_sched_needs_restart(struct blk_mq_hw_ctx *hctx) diff --git a/block/blk-mq.c b/block/blk-mq.c index 711883384585..21795c6575bc 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -40,7 +40,7 @@ static LIST_HEAD(all_q_list); /* * Check if any of the ctx's have pending work in this hardware queue */ -static bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx) +bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx) { return sbitmap_any_bit_set(&hctx->ctx_map) || !list_empty_careful(&hctx->dispatch) || @@ -345,6 +345,7 @@ void __blk_mq_finish_request(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, blk_mq_put_tag(hctx, hctx->tags, ctx, rq->tag); if (sched_tag != -1) blk_mq_sched_completed_request(hctx, rq); + blk_mq_sched_restart_queues(hctx); blk_queue_exit(q); } diff --git a/block/blk-mq.h b/block/blk-mq.h index 6c24b901acd7..077a4003f1fd 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -33,6 +33,7 @@ int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr); void blk_mq_wake_waiters(struct request_queue *q); bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *, struct list_head *); void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list); +bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx); /* * Internal helpers for allocating/freeing the request map diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 0ee283f3cffe..883b8abe4305 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -607,6 +607,7 @@ struct request_queue { #define QUEUE_FLAG_FLUSH_NQ 25 /* flush not queueuable */ #define QUEUE_FLAG_DAX 26 /* device supports DAX */ #define QUEUE_FLAG_STATS 27 /* track rq completion times */ +#define QUEUE_FLAG_RESTART 28 /* queue needs restart at completion */ #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ (1 << QUEUE_FLAG_STACKABLE) | \ From c13660a08c8b3bb49def4374bfd414aaaa564662 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 26 Jan 2017 12:40:07 -0700 Subject: [PATCH 45/49] blk-mq-sched: change ->dispatch_requests() to ->dispatch_request() When we invoke dispatch_requests(), the scheduler empties everything into the passed in list. This isn't always a good thing, since it means that we remove items that we could have potentially merged with. Change the function to dispatch single requests at the time. If we do that, we can backoff exactly at the point where the device can't consume more IO, and leave the rest with the scheduler for better merging and future dispatch decision making. Signed-off-by: Jens Axboe Reviewed-by: Omar Sandoval Tested-by: Hannes Reinecke --- block/blk-mq-sched.c | 21 ++++++++++++++------- block/blk-mq.c | 2 +- block/mq-deadline.c | 10 ++++++---- include/linux/elevator.h | 2 +- 4 files changed, 22 insertions(+), 13 deletions(-) diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index fcc0e893d687..c27613de80c5 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -201,15 +201,22 @@ void blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx) * leave them there for as long as we can. Mark the hw queue as * needing a restart in that case. */ - if (list_empty(&rq_list)) { - if (e && e->type->ops.mq.dispatch_requests) - e->type->ops.mq.dispatch_requests(hctx, &rq_list); - else - blk_mq_flush_busy_ctxs(hctx, &rq_list); - } else + if (!list_empty(&rq_list)) { blk_mq_sched_mark_restart(hctx); + blk_mq_dispatch_rq_list(hctx, &rq_list); + } else if (!e || !e->type->ops.mq.dispatch_request) { + blk_mq_flush_busy_ctxs(hctx, &rq_list); + blk_mq_dispatch_rq_list(hctx, &rq_list); + } else { + do { + struct request *rq; - blk_mq_dispatch_rq_list(hctx, &rq_list); + rq = e->type->ops.mq.dispatch_request(hctx); + if (!rq) + break; + list_add(&rq->queuelist, &rq_list); + } while (blk_mq_dispatch_rq_list(hctx, &rq_list)); + } } void blk_mq_sched_move_to_dispatch(struct blk_mq_hw_ctx *hctx, diff --git a/block/blk-mq.c b/block/blk-mq.c index 21795c6575bc..301ae29fd229 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -998,7 +998,7 @@ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list) */ if (!list_empty(list)) { spin_lock(&hctx->lock); - list_splice(list, &hctx->dispatch); + list_splice_init(list, &hctx->dispatch); spin_unlock(&hctx->lock); /* diff --git a/block/mq-deadline.c b/block/mq-deadline.c index a01986d7b6fb..d93ec713fa62 100644 --- a/block/mq-deadline.c +++ b/block/mq-deadline.c @@ -287,14 +287,16 @@ done: return rq; } -static void dd_dispatch_requests(struct blk_mq_hw_ctx *hctx, - struct list_head *rq_list) +static struct request *dd_dispatch_request(struct blk_mq_hw_ctx *hctx) { struct deadline_data *dd = hctx->queue->elevator->elevator_data; + struct request *rq; spin_lock(&dd->lock); - blk_mq_sched_move_to_dispatch(hctx, rq_list, __dd_dispatch_request); + rq = __dd_dispatch_request(hctx); spin_unlock(&dd->lock); + + return rq; } static void dd_exit_queue(struct elevator_queue *e) @@ -517,7 +519,7 @@ static struct elv_fs_entry deadline_attrs[] = { static struct elevator_type mq_deadline = { .ops.mq = { .insert_requests = dd_insert_requests, - .dispatch_requests = dd_dispatch_requests, + .dispatch_request = dd_dispatch_request, .next_request = elv_rb_latter_request, .former_request = elv_rb_former_request, .bio_merge = dd_bio_merge, diff --git a/include/linux/elevator.h b/include/linux/elevator.h index ecb96fd67c6d..b5825c4f06f7 100644 --- a/include/linux/elevator.h +++ b/include/linux/elevator.h @@ -92,7 +92,7 @@ struct elevator_mq_ops { struct request *(*get_request)(struct request_queue *, unsigned int, struct blk_mq_alloc_data *); void (*put_request)(struct request *); void (*insert_requests)(struct blk_mq_hw_ctx *, struct list_head *, bool); - void (*dispatch_requests)(struct blk_mq_hw_ctx *, struct list_head *); + struct request *(*dispatch_request)(struct blk_mq_hw_ctx *); bool (*has_work)(struct blk_mq_hw_ctx *); void (*completed_request)(struct blk_mq_hw_ctx *, struct request *); void (*started_request)(struct request *); From f73f44eb00cb136990cfb7d40e436c13d7669ec8 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 27 Jan 2017 08:30:47 -0700 Subject: [PATCH 46/49] block: add a op_is_flush helper This centralizes the checks for bios that needs to be go into the flush state machine. Signed-off-by: Christoph Hellwig Reviewed-by: Martin K. Petersen Reviewed-by: Bart Van Assche Signed-off-by: Jens Axboe --- block/blk-core.c | 8 ++++---- block/blk-mq-sched.c | 5 ++--- block/blk-mq.c | 4 ++-- drivers/md/bcache/request.c | 2 +- drivers/md/dm-cache-target.c | 13 +++---------- drivers/md/dm-thin.c | 13 +++++-------- include/linux/blk_types.h | 9 +++++++++ 7 files changed, 26 insertions(+), 28 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index a61f1407f4f6..b830e14117dd 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1035,7 +1035,7 @@ static bool blk_rq_should_init_elevator(struct bio *bio) * Flush requests do not use the elevator so skip initialization. * This allows a request to share the flush and elevator data. */ - if (bio->bi_opf & (REQ_PREFLUSH | REQ_FUA)) + if (op_is_flush(bio->bi_opf)) return false; return true; @@ -1641,7 +1641,7 @@ static blk_qc_t blk_queue_bio(struct request_queue *q, struct bio *bio) return BLK_QC_T_NONE; } - if (bio->bi_opf & (REQ_PREFLUSH | REQ_FUA)) { + if (op_is_flush(bio->bi_opf)) { spin_lock_irq(q->queue_lock); where = ELEVATOR_INSERT_FLUSH; goto get_rq; @@ -2145,7 +2145,7 @@ int blk_insert_cloned_request(struct request_queue *q, struct request *rq) */ BUG_ON(blk_queued_rq(rq)); - if (rq->cmd_flags & (REQ_PREFLUSH | REQ_FUA)) + if (op_is_flush(rq->cmd_flags)) where = ELEVATOR_INSERT_FLUSH; add_acct_request(q, rq, where); @@ -3256,7 +3256,7 @@ void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule) /* * rq is already accounted, so use raw insert */ - if (rq->cmd_flags & (REQ_PREFLUSH | REQ_FUA)) + if (op_is_flush(rq->cmd_flags)) __elv_add_request(q, rq, ELEVATOR_INSERT_FLUSH); else __elv_add_request(q, rq, ELEVATOR_INSERT_SORT_MERGE); diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index c27613de80c5..4139b07ab33b 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -111,7 +111,6 @@ struct request *blk_mq_sched_get_request(struct request_queue *q, struct blk_mq_hw_ctx *hctx; struct blk_mq_ctx *ctx; struct request *rq; - const bool is_flush = op & (REQ_PREFLUSH | REQ_FUA); blk_queue_enter_live(q); ctx = blk_mq_get_ctx(q); @@ -126,7 +125,7 @@ struct request *blk_mq_sched_get_request(struct request_queue *q, * Flush requests are special and go directly to the * dispatch list. */ - if (!is_flush && e->type->ops.mq.get_request) { + if (!op_is_flush(op) && e->type->ops.mq.get_request) { rq = e->type->ops.mq.get_request(q, op, data); if (rq) rq->rq_flags |= RQF_QUEUED; @@ -139,7 +138,7 @@ struct request *blk_mq_sched_get_request(struct request_queue *q, } if (rq) { - if (!is_flush) { + if (!op_is_flush(op)) { rq->elv.icq = NULL; if (e && e->type->icq_cache) blk_mq_sched_assign_ioc(q, rq, bio); diff --git a/block/blk-mq.c b/block/blk-mq.c index 301ae29fd229..da2123dd681e 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1406,7 +1406,7 @@ insert: static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) { const int is_sync = op_is_sync(bio->bi_opf); - const int is_flush_fua = bio->bi_opf & (REQ_PREFLUSH | REQ_FUA); + const int is_flush_fua = op_is_flush(bio->bi_opf); struct blk_mq_alloc_data data = { .flags = 0 }; struct request *rq; unsigned int request_count = 0, srcu_idx; @@ -1527,7 +1527,7 @@ done: static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio) { const int is_sync = op_is_sync(bio->bi_opf); - const int is_flush_fua = bio->bi_opf & (REQ_PREFLUSH | REQ_FUA); + const int is_flush_fua = op_is_flush(bio->bi_opf); struct blk_plug *plug; unsigned int request_count = 0; struct blk_mq_alloc_data data = { .flags = 0 }; diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c index 76d20875503c..01035e718c1c 100644 --- a/drivers/md/bcache/request.c +++ b/drivers/md/bcache/request.c @@ -666,7 +666,7 @@ static inline struct search *search_alloc(struct bio *bio, s->iop.write_prio = 0; s->iop.error = 0; s->iop.flags = 0; - s->iop.flush_journal = (bio->bi_opf & (REQ_PREFLUSH|REQ_FUA)) != 0; + s->iop.flush_journal = op_is_flush(bio->bi_opf); s->iop.wq = bcache_wq; return s; diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c index e04c61e0839e..5b9cf56de8ef 100644 --- a/drivers/md/dm-cache-target.c +++ b/drivers/md/dm-cache-target.c @@ -787,8 +787,7 @@ static void check_if_tick_bio_needed(struct cache *cache, struct bio *bio) struct per_bio_data *pb = get_per_bio_data(bio, pb_data_size); spin_lock_irqsave(&cache->lock, flags); - if (cache->need_tick_bio && - !(bio->bi_opf & (REQ_FUA | REQ_PREFLUSH)) && + if (cache->need_tick_bio && !op_is_flush(bio->bi_opf) && bio_op(bio) != REQ_OP_DISCARD) { pb->tick = true; cache->need_tick_bio = false; @@ -828,11 +827,6 @@ static dm_oblock_t get_bio_block(struct cache *cache, struct bio *bio) return to_oblock(block_nr); } -static int bio_triggers_commit(struct cache *cache, struct bio *bio) -{ - return bio->bi_opf & (REQ_PREFLUSH | REQ_FUA); -} - /* * You must increment the deferred set whilst the prison cell is held. To * encourage this, we ask for 'cell' to be passed in. @@ -884,7 +878,7 @@ static void issue(struct cache *cache, struct bio *bio) { unsigned long flags; - if (!bio_triggers_commit(cache, bio)) { + if (!op_is_flush(bio->bi_opf)) { accounted_request(cache, bio); return; } @@ -1069,8 +1063,7 @@ static void dec_io_migrations(struct cache *cache) static bool discard_or_flush(struct bio *bio) { - return bio_op(bio) == REQ_OP_DISCARD || - bio->bi_opf & (REQ_PREFLUSH | REQ_FUA); + return bio_op(bio) == REQ_OP_DISCARD || op_is_flush(bio->bi_opf); } static void __cell_defer(struct cache *cache, struct dm_bio_prison_cell *cell) diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c index d1c05c12a9db..110982db4b48 100644 --- a/drivers/md/dm-thin.c +++ b/drivers/md/dm-thin.c @@ -699,7 +699,7 @@ static void remap_to_origin(struct thin_c *tc, struct bio *bio) static int bio_triggers_commit(struct thin_c *tc, struct bio *bio) { - return (bio->bi_opf & (REQ_PREFLUSH | REQ_FUA)) && + return op_is_flush(bio->bi_opf) && dm_thin_changed_this_transaction(tc->td); } @@ -870,8 +870,7 @@ static void __inc_remap_and_issue_cell(void *context, struct bio *bio; while ((bio = bio_list_pop(&cell->bios))) { - if (bio->bi_opf & (REQ_PREFLUSH | REQ_FUA) || - bio_op(bio) == REQ_OP_DISCARD) + if (op_is_flush(bio->bi_opf) || bio_op(bio) == REQ_OP_DISCARD) bio_list_add(&info->defer_bios, bio); else { inc_all_io_entry(info->tc->pool, bio); @@ -1716,9 +1715,8 @@ static void __remap_and_issue_shared_cell(void *context, struct bio *bio; while ((bio = bio_list_pop(&cell->bios))) { - if ((bio_data_dir(bio) == WRITE) || - (bio->bi_opf & (REQ_PREFLUSH | REQ_FUA) || - bio_op(bio) == REQ_OP_DISCARD)) + if (bio_data_dir(bio) == WRITE || op_is_flush(bio->bi_opf) || + bio_op(bio) == REQ_OP_DISCARD) bio_list_add(&info->defer_bios, bio); else { struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));; @@ -2635,8 +2633,7 @@ static int thin_bio_map(struct dm_target *ti, struct bio *bio) return DM_MAPIO_SUBMITTED; } - if (bio->bi_opf & (REQ_PREFLUSH | REQ_FUA) || - bio_op(bio) == REQ_OP_DISCARD) { + if (op_is_flush(bio->bi_opf) || bio_op(bio) == REQ_OP_DISCARD) { thin_defer_bio_with_throttle(tc, bio); return DM_MAPIO_SUBMITTED; } diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 0e5b1cd5113c..37c9a43c5e78 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -220,6 +220,15 @@ static inline bool op_is_write(unsigned int op) return (op & 1); } +/* + * Check if the bio or request is one that needs special treatment in the + * flush state machine. + */ +static inline bool op_is_flush(unsigned int op) +{ + return op & (REQ_FUA | REQ_PREFLUSH); +} + /* * Reads are always treated as synchronous, as are requests with the FUA or * PREFLUSH flag. Other operations may be marked as synchronous using the From bd6737f1ae92e2f1c6e8362efe96dbe7f18fa07d Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Fri, 27 Jan 2017 01:00:47 -0700 Subject: [PATCH 47/49] blk-mq-sched: add flush insertion into blk_mq_sched_insert_request() Instead of letting the caller check this and handle the details of inserting a flush request, put the logic in the scheduler insertion function. This fixes direct flush insertion outside of the usual make_request_fn calls, like from dm via blk_insert_cloned_request(). Signed-off-by: Jens Axboe --- block/blk-core.c | 2 +- block/blk-exec.c | 2 +- block/blk-flush.c | 2 +- block/blk-mq-sched.c | 58 ++++++++++++++++++++++++++++++++++++++++++++ block/blk-mq-sched.h | 45 +++++----------------------------- block/blk-mq-tag.c | 8 +++++- block/blk-mq.c | 25 ++++++++++--------- block/blk-mq.h | 2 ++ 8 files changed, 89 insertions(+), 55 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index b830e14117dd..4bfd8674afd0 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -2129,7 +2129,7 @@ int blk_insert_cloned_request(struct request_queue *q, struct request *rq) if (q->mq_ops) { if (blk_queue_io_stat(q)) blk_account_io_start(rq, true); - blk_mq_sched_insert_request(rq, false, true, false); + blk_mq_sched_insert_request(rq, false, true, false, false); return 0; } diff --git a/block/blk-exec.c b/block/blk-exec.c index 86656fdfa637..ed1f10165268 100644 --- a/block/blk-exec.c +++ b/block/blk-exec.c @@ -66,7 +66,7 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk, * be reused after dying flag is set */ if (q->mq_ops) { - blk_mq_sched_insert_request(rq, at_head, true, false); + blk_mq_sched_insert_request(rq, at_head, true, false, false); return; } diff --git a/block/blk-flush.c b/block/blk-flush.c index d7de34ee39c2..4427896641ac 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -456,7 +456,7 @@ void blk_insert_flush(struct request *rq) if ((policy & REQ_FSEQ_DATA) && !(policy & (REQ_FSEQ_PREFLUSH | REQ_FSEQ_POSTFLUSH))) { if (q->mq_ops) - blk_mq_sched_insert_request(rq, false, true, false); + blk_mq_sched_insert_request(rq, false, true, false, false); else list_add_tail(&rq->queuelist, &q->queue_head); return; diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index 4139b07ab33b..1112752f888d 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -335,6 +335,64 @@ void blk_mq_sched_restart_queues(struct blk_mq_hw_ctx *hctx) } } +/* + * Add flush/fua to the queue. If we fail getting a driver tag, then + * punt to the requeue list. Requeue will re-invoke us from a context + * that's safe to block from. + */ +static void blk_mq_sched_insert_flush(struct blk_mq_hw_ctx *hctx, + struct request *rq, bool can_block) +{ + if (blk_mq_get_driver_tag(rq, &hctx, can_block)) { + blk_insert_flush(rq); + blk_mq_run_hw_queue(hctx, true); + } else + blk_mq_add_to_requeue_list(rq, true, true); +} + +void blk_mq_sched_insert_request(struct request *rq, bool at_head, + bool run_queue, bool async, bool can_block) +{ + struct request_queue *q = rq->q; + struct elevator_queue *e = q->elevator; + struct blk_mq_ctx *ctx = rq->mq_ctx; + struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); + + if (rq->tag == -1 && (rq->cmd_flags & (REQ_PREFLUSH | REQ_FUA))) { + blk_mq_sched_insert_flush(hctx, rq, can_block); + return; + } + + if (e && e->type->ops.mq.insert_requests) { + LIST_HEAD(list); + + list_add(&rq->queuelist, &list); + e->type->ops.mq.insert_requests(hctx, &list, at_head); + } else { + spin_lock(&ctx->lock); + __blk_mq_insert_request(hctx, rq, at_head); + spin_unlock(&ctx->lock); + } + + if (run_queue) + blk_mq_run_hw_queue(hctx, async); +} + +void blk_mq_sched_insert_requests(struct request_queue *q, + struct blk_mq_ctx *ctx, + struct list_head *list, bool run_queue_async) +{ + struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); + struct elevator_queue *e = hctx->queue->elevator; + + if (e && e->type->ops.mq.insert_requests) + e->type->ops.mq.insert_requests(hctx, list, false); + else + blk_mq_insert_requests(hctx, ctx, list); + + blk_mq_run_hw_queue(hctx, run_queue_async); +} + static void blk_mq_sched_free_tags(struct blk_mq_tag_set *set, struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx) diff --git a/block/blk-mq-sched.h b/block/blk-mq-sched.h index becbc7840364..9478aaeb48c5 100644 --- a/block/blk-mq-sched.h +++ b/block/blk-mq-sched.h @@ -21,6 +21,12 @@ bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio); bool blk_mq_sched_try_insert_merge(struct request_queue *q, struct request *rq); void blk_mq_sched_restart_queues(struct blk_mq_hw_ctx *hctx); +void blk_mq_sched_insert_request(struct request *rq, bool at_head, + bool run_queue, bool async, bool can_block); +void blk_mq_sched_insert_requests(struct request_queue *q, + struct blk_mq_ctx *ctx, + struct list_head *list, bool run_queue_async); + void blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx); void blk_mq_sched_move_to_dispatch(struct blk_mq_hw_ctx *hctx, struct list_head *rq_list, @@ -62,45 +68,6 @@ static inline void blk_mq_sched_put_rq_priv(struct request_queue *q, e->type->ops.mq.put_rq_priv(q, rq); } -static inline void -blk_mq_sched_insert_request(struct request *rq, bool at_head, bool run_queue, - bool async) -{ - struct request_queue *q = rq->q; - struct elevator_queue *e = q->elevator; - struct blk_mq_ctx *ctx = rq->mq_ctx; - struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); - - if (e && e->type->ops.mq.insert_requests) { - LIST_HEAD(list); - - list_add(&rq->queuelist, &list); - e->type->ops.mq.insert_requests(hctx, &list, at_head); - } else { - spin_lock(&ctx->lock); - __blk_mq_insert_request(hctx, rq, at_head); - spin_unlock(&ctx->lock); - } - - if (run_queue) - blk_mq_run_hw_queue(hctx, async); -} - -static inline void -blk_mq_sched_insert_requests(struct request_queue *q, struct blk_mq_ctx *ctx, - struct list_head *list, bool run_queue_async) -{ - struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); - struct elevator_queue *e = hctx->queue->elevator; - - if (e && e->type->ops.mq.insert_requests) - e->type->ops.mq.insert_requests(hctx, list, false); - else - blk_mq_insert_requests(hctx, ctx, list); - - blk_mq_run_hw_queue(hctx, run_queue_async); -} - static inline bool blk_mq_sched_allow_merge(struct request_queue *q, struct request *rq, struct bio *bio) diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index f8de2dbbb29f..54c84363c1b2 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -106,6 +106,7 @@ unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data) struct sbq_wait_state *ws; DEFINE_WAIT(wait); unsigned int tag_offset; + bool drop_ctx; int tag; if (data->flags & BLK_MQ_REQ_RESERVED) { @@ -128,6 +129,7 @@ unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data) return BLK_MQ_TAG_FAIL; ws = bt_wait_ptr(bt, data->hctx); + drop_ctx = data->ctx == NULL; do { prepare_to_wait(&ws->wait, &wait, TASK_UNINTERRUPTIBLE); @@ -150,7 +152,8 @@ unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data) if (tag != -1) break; - blk_mq_put_ctx(data->ctx); + if (data->ctx) + blk_mq_put_ctx(data->ctx); io_schedule(); @@ -166,6 +169,9 @@ unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data) ws = bt_wait_ptr(bt, data->hctx); } while (1); + if (drop_ctx && data->ctx) + blk_mq_put_ctx(data->ctx); + finish_wait(&ws->wait, &wait); found_tag: diff --git a/block/blk-mq.c b/block/blk-mq.c index da2123dd681e..60dac10228fe 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -568,13 +568,13 @@ static void blk_mq_requeue_work(struct work_struct *work) rq->rq_flags &= ~RQF_SOFTBARRIER; list_del_init(&rq->queuelist); - blk_mq_sched_insert_request(rq, true, false, false); + blk_mq_sched_insert_request(rq, true, false, false, true); } while (!list_empty(&rq_list)) { rq = list_entry(rq_list.next, struct request, queuelist); list_del_init(&rq->queuelist); - blk_mq_sched_insert_request(rq, false, false, false); + blk_mq_sched_insert_request(rq, false, false, false, true); } blk_mq_run_hw_queues(q, false); @@ -847,12 +847,11 @@ static inline unsigned int queued_to_index(unsigned int queued) return min(BLK_MQ_MAX_DISPATCH_ORDER - 1, ilog2(queued) + 1); } -static bool blk_mq_get_driver_tag(struct request *rq, - struct blk_mq_hw_ctx **hctx, bool wait) +bool blk_mq_get_driver_tag(struct request *rq, struct blk_mq_hw_ctx **hctx, + bool wait) { struct blk_mq_alloc_data data = { .q = rq->q, - .ctx = rq->mq_ctx, .hctx = blk_mq_map_queue(rq->q, rq->mq_ctx->cpu), .flags = wait ? 0 : BLK_MQ_REQ_NOWAIT, }; @@ -1395,7 +1394,7 @@ static void blk_mq_try_issue_directly(struct request *rq, blk_qc_t *cookie) } insert: - blk_mq_sched_insert_request(rq, false, true, true); + blk_mq_sched_insert_request(rq, false, true, true, false); } /* @@ -1446,10 +1445,12 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) cookie = request_to_qc_t(data.hctx, rq); if (unlikely(is_flush_fua)) { + blk_mq_put_ctx(data.ctx); blk_mq_bio_to_request(rq, bio); blk_mq_get_driver_tag(rq, NULL, true); blk_insert_flush(rq); - goto run_queue; + blk_mq_run_hw_queue(data.hctx, true); + goto done; } plug = current->plug; @@ -1502,7 +1503,7 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) blk_mq_put_ctx(data.ctx); blk_mq_bio_to_request(rq, bio); blk_mq_sched_insert_request(rq, false, true, - !is_sync || is_flush_fua); + !is_sync || is_flush_fua, true); goto done; } if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) { @@ -1512,7 +1513,6 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) * latter allows for merging opportunities and more efficient * dispatching. */ -run_queue: blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua); } blk_mq_put_ctx(data.ctx); @@ -1568,10 +1568,12 @@ static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio) cookie = request_to_qc_t(data.hctx, rq); if (unlikely(is_flush_fua)) { + blk_mq_put_ctx(data.ctx); blk_mq_bio_to_request(rq, bio); blk_mq_get_driver_tag(rq, NULL, true); blk_insert_flush(rq); - goto run_queue; + blk_mq_run_hw_queue(data.hctx, true); + goto done; } /* @@ -1612,7 +1614,7 @@ static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio) blk_mq_put_ctx(data.ctx); blk_mq_bio_to_request(rq, bio); blk_mq_sched_insert_request(rq, false, true, - !is_sync || is_flush_fua); + !is_sync || is_flush_fua, true); goto done; } if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) { @@ -1622,7 +1624,6 @@ static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio) * latter allows for merging opportunities and more efficient * dispatching. */ -run_queue: blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua); } diff --git a/block/blk-mq.h b/block/blk-mq.h index 077a4003f1fd..57cdbf6c0cee 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -34,6 +34,8 @@ void blk_mq_wake_waiters(struct request_queue *q); bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *, struct list_head *); void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list); bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx); +bool blk_mq_get_driver_tag(struct request *rq, struct blk_mq_hw_ctx **hctx, + bool wait); /* * Internal helpers for allocating/freeing the request map From f3a8ab7d55bc49b44baa229723e0b5b6ebacac4a Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Fri, 27 Jan 2017 09:08:23 -0700 Subject: [PATCH 48/49] block: cleanup remaining manual checks for PREFLUSH|FUA Use op_is_flush() where applicable. Signed-off-by: Jens Axboe --- block/blk-core.c | 2 +- block/blk-mq-sched.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 4bfd8674afd0..02833ce5664e 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1880,7 +1880,7 @@ generic_make_request_checks(struct bio *bio) * drivers without flush support don't have to worry * about them. */ - if ((bio->bi_opf & (REQ_PREFLUSH | REQ_FUA)) && + if (op_is_flush(bio->bi_opf) && !test_bit(QUEUE_FLAG_WC, &q->queue_flags)) { bio->bi_opf &= ~(REQ_PREFLUSH | REQ_FUA); if (!nr_sectors) { diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index 1112752f888d..114814ec3d49 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -358,7 +358,7 @@ void blk_mq_sched_insert_request(struct request *rq, bool at_head, struct blk_mq_ctx *ctx = rq->mq_ctx; struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); - if (rq->tag == -1 && (rq->cmd_flags & (REQ_PREFLUSH | REQ_FUA))) { + if (rq->tag == -1 && op_is_flush(rq->cmd_flags)) { blk_mq_sched_insert_flush(hctx, rq, can_block); return; } From 400f73b23f457a82288814e21af57dbc9f3f2afd Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Fri, 27 Jan 2017 15:03:01 -0700 Subject: [PATCH 49/49] blk-mq: fix debugfs compilation issues This fixes a couple of problems: 1. In the !CONFIG_DEBUG_FS case, the stub definitions were bogus. 2. In the !CONFIG_BLOCK case, blk-mq-debugfs.c shouldn't be compiled at all. Fix the stub definitions and add a CONFIG_BLK_DEBUG_FS Kconfig option. Fixes: 07e4fead45e6 ("blk-mq: create debugfs directory tree") Signed-off-by: Omar Sandoval Augment Kconfig description. Signed-off-by: Jens Axboe --- block/Kconfig | 12 ++++++++++++ block/Makefile | 2 +- block/blk-mq.h | 11 ++++++----- 3 files changed, 19 insertions(+), 6 deletions(-) diff --git a/block/Kconfig b/block/Kconfig index 8bf114a3858a..7f659b23850c 100644 --- a/block/Kconfig +++ b/block/Kconfig @@ -147,6 +147,18 @@ config BLK_WBT_MQ Multiqueue currently doesn't have support for IO scheduling, enabling this option is recommended. +config BLK_DEBUG_FS + bool "Block layer debugging information in debugfs" + default y + depends on DEBUG_FS + ---help--- + Include block layer debugging information in debugfs. This information + is mostly useful for kernel developers, but it doesn't incur any cost + at runtime. + + Unless you are building a kernel for a tiny system, you should + say Y here. + menu "Partition Types" source "block/partitions/Kconfig" diff --git a/block/Makefile b/block/Makefile index 6cabe6bd2882..317165f8708c 100644 --- a/block/Makefile +++ b/block/Makefile @@ -26,4 +26,4 @@ obj-$(CONFIG_BLK_DEV_INTEGRITY) += bio-integrity.o blk-integrity.o t10-pi.o obj-$(CONFIG_BLK_MQ_PCI) += blk-mq-pci.o obj-$(CONFIG_BLK_DEV_ZONED) += blk-zoned.o obj-$(CONFIG_BLK_WBT) += blk-wbt.o -obj-$(CONFIG_DEBUG_FS) += blk-mq-debugfs.o +obj-$(CONFIG_BLK_DEBUG_FS) += blk-mq-debugfs.o diff --git a/block/blk-mq.h b/block/blk-mq.h index 57cdbf6c0cee..b52abd62b1b0 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -84,7 +84,7 @@ extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx); /* * debugfs helpers */ -#ifdef CONFIG_DEBUG_FS +#ifdef CONFIG_BLK_DEBUG_FS void blk_mq_debugfs_init(void); int blk_mq_debugfs_register(struct request_queue *q, const char *name); void blk_mq_debugfs_unregister(struct request_queue *q); @@ -95,21 +95,22 @@ static inline void blk_mq_debugfs_init(void) { } -int blk_mq_debugfs_register(struct request_queue *q, const char *name); +static inline int blk_mq_debugfs_register(struct request_queue *q, + const char *name) { return 0; } -void blk_mq_debugfs_unregister(struct request_queue *q) +static inline void blk_mq_debugfs_unregister(struct request_queue *q) { } -int blk_mq_debugfs_register_hctxs(struct request_queue *q) +static inline int blk_mq_debugfs_register_hctxs(struct request_queue *q) { return 0; } -void blk_mq_debugfs_unregister_hctxs(struct request_queue *q) +static inline void blk_mq_debugfs_unregister_hctxs(struct request_queue *q) { } #endif