Konstantin Khlebnikov ea18e0f0a6 block/diskstats: accumulate all per-cpu counters in one pass ... Reading /proc/diskstats iterates over all cpus for summing each field. It's faster to sum all fields in one pass. Hammering /proc/diskstats with fio shows 2x performance improvement: fio --name=test --numjobs=$JOBS --filename=/proc/diskstats \ --size=1k --bs=1k --fallocate=none --create_on_open=1 \ --time_based=1 --runtime=10 --invalidate=0 --group_report JOBS=1 JOBS=10 Before: 7k iops 64k iops After: 18k iops 120k iops Also this way code is more compact: add/remove: 1/0 grow/shrink: 0/2 up/down: 194/-1540 (-1346) Function old new delta part_stat_read_all - 194 +194 diskstats_show 1344 631 -713 part_stat_show 1219 392 -827 Total: Before=14966947, After=14965601, chg -0.01% Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Jens Axboe <axboe@kernel.dk>		2020-03-25 08:49:10 -06:00
..
partitions	block: merge partition-generic.c and check.c	2020-03-24 07:57:08 -06:00
badblocks.c	block: switch all files cleared marked as GPLv2 to SPDX tags	2019-04-30 16:11:57 -06:00
bfq-cgroup.c	block, bfq: invoke flush_idle_tree after reparent_active_queues in pd_offline	2020-03-21 14:31:03 -06:00
bfq-iosched.c	block, bfq: turn put_queue into release_process_ref in __bfq_bic_change_cgroup	2020-03-21 14:31:00 -06:00
bfq-iosched.h	block, bfq: turn put_queue into release_process_ref in __bfq_bic_change_cgroup	2020-03-21 14:31:00 -06:00
bfq-wf2q.c	block, bfq: get a ref to a group when adding it to a service tree	2020-02-03 06:58:15 -07:00
bio-integrity.c	block: fix memleak of bio integrity data	2019-12-05 11:38:36 -07:00
bio.c	block/diskstats: more accurate approximation of io_ticks for slow disks	2020-03-25 08:49:08 -06:00
blk-cgroup-rwstat.c	blk-cgroup: separate out blkg_rwstat under CONFIG_BLK_CGROUP_RWSTAT	2019-11-07 12:28:13 -07:00
blk-cgroup-rwstat.h	blk-cgroup: separate out blkg_rwstat under CONFIG_BLK_CGROUP_RWSTAT	2019-11-07 12:28:13 -07:00
blk-cgroup.c	blk-cgroup: remove blkcg_drain_queue	2019-12-12 09:26:55 -07:00
blk-core.c	block/diskstats: more accurate approximation of io_ticks for slow disks	2020-03-25 08:49:08 -06:00
blk-exec.c	block: account statistics for passthrough requests	2019-10-10 17:52:31 -06:00
blk-flush.c	block: cleanup comment for blk_flush_complete_seq	2020-03-12 07:42:54 -06:00
blk-integrity.c	block: centralize PI remapping logic to the block layer	2019-09-17 20:03:49 -06:00
blk-ioc.c	block: Fix use-after-free issue accessing struct io_cq	2020-03-12 07:07:38 -06:00
blk-iocost.c	blk-iocost: remove duplicated lines in comments	2020-03-12 08:02:20 -06:00
blk-iolatency.c	blkcg: s/RQ_QOS_CGROUP/RQ_QOS_LATENCY/	2019-08-28 21:17:08 -06:00
blk-lib.c	block: fix 32 bit overflow in __blkdev_issue_discard()	2018-11-14 08:17:18 -07:00
blk-map.c	block: fix memleak when __blk_rq_map_user_iov() is failed	2019-12-20 11:52:01 -07:00
blk-merge.c	block: fix get_max_segment_size() overflow on 32bit arch	2020-01-14 13:37:40 -07:00
blk-mq-cpumap.c	blk-mq: balance mapping between present CPUs and queues	2019-08-04 21:43:12 -06:00
blk-mq-debugfs-zoned.c	block: Cleanup license notice	2019-01-17 21:21:40 -07:00
blk-mq-debugfs.c	for-5.3/block-20190708	2019-07-09 10:45:06 -07:00
blk-mq-debugfs.h	blk-mq: no need to check return value of debugfs_create functions	2019-06-13 03:00:30 -06:00
blk-mq-pci.c	block: Fix blk_mq_*_map_queues() kernel-doc headers	2019-05-31 15:12:34 -06:00
blk-mq-rdma.c	block: Fix blk_mq_*_map_queues() kernel-doc headers	2019-05-31 15:12:34 -06:00
blk-mq-sched.c	blk-mq: insert passthrough request into hctx->dispatch directly	2020-02-24 18:50:48 -07:00
blk-mq-sched.h	block: blk-mq: Remove blk_mq_sched_started_request and started_request	2019-07-23 07:25:09 -06:00
blk-mq-sysfs.c	blk-mq: make sure that line break can be printed	2019-11-04 07:14:10 -07:00
blk-mq-tag.c	blk-mq: Remove some unused function arguments	2020-02-26 10:34:41 -07:00
blk-mq-tag.h	blk-mq: Remove some unused function arguments	2020-02-26 10:34:41 -07:00
blk-mq-virtio.c	block: Fix blk_mq_*_map_queues() kernel-doc headers	2019-05-31 15:12:34 -06:00
blk-mq.c	block: remove unneeded argument from blk_alloc_flush_queue	2020-03-12 07:42:54 -06:00
blk-mq.h	blk-mq: Remove some unused function arguments	2020-02-26 10:34:41 -07:00
blk-pm.c	block: bypass blk_set_runtime_active for uninitialized q->dev	2019-09-12 07:11:56 -06:00
blk-pm.h	block: remove the queue_lock indirection	2018-11-15 12:17:28 -07:00
blk-rq-qos.c	blk-wbt: fix performance regression in wbt scale_up/scale_down	2019-10-06 09:26:41 -06:00
blk-rq-qos.h	blk-rq-qos: fix first node deletion of rq_qos_del()	2019-10-15 10:13:13 -06:00
blk-settings.c	block: fix an integer overflow in logical block size	2020-01-15 21:43:09 -07:00
blk-softirq.c	block: Don't disable interrupts in trigger_softirq()	2019-11-18 07:29:22 -07:00
blk-stat.c	blk-stat: Optimise blk_stat_add()	2019-10-07 21:19:10 -06:00
blk-stat.h	block: deactivate blk_stat timer in wbt_disable_default()	2018-12-12 06:47:51 -07:00
blk-sysfs.c	block: Remove "dying" checks from sysfs callbacks	2019-10-07 08:31:59 -06:00
blk-throttle.c	blk-cgroup: separate out blkg_rwstat under CONFIG_BLK_CGROUP_RWSTAT	2019-11-07 12:28:13 -07:00
blk-timeout.c	block: add SPDX tags to block layer files missing licensing information	2019-04-30 16:12:03 -06:00
blk-wbt.c	blk-wbt: fix performance regression in wbt scale_up/scale_down	2019-10-06 09:26:41 -06:00
blk-wbt.h	block/rq_qos: implement rq_qos_ops->queue_depth_changed()	2019-08-28 21:17:07 -06:00
blk-zoned.c	block, zoned: fix integer overflow with BLKRESETZONE et al	2020-03-12 09:10:52 -06:00
blk.h	block: move sysfs methods shared by disks and partitions to genhd.c	2020-03-24 07:57:07 -06:00
bounce.c	block: remove the i argument to bio_for_each_segment_all	2019-04-30 09:26:13 -06:00
bsg-lib.c	block: Fix the type of 'sts' in bsg_queue_rq()	2019-12-20 11:52:01 -07:00
bsg.c	compat_ioctl: bsg: add handler	2020-01-03 09:33:21 +01:00
cmdline-parser.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
elevator.c	Merge branch 'for-linus' into for-5.5/block	2019-11-07 12:27:19 -07:00
genhd.c	block/diskstats: accumulate all per-cpu counters in one pass	2020-03-25 08:49:10 -06:00
ioctl.c	compat_ioctl: simplify up block/ioctl.c	2020-01-03 09:42:52 +01:00
ioprio.c	docs: block: convert to ReST	2019-07-15 09:20:27 -03:00
Kconfig	block: Allow t10-pi to be modular	2020-01-06 20:59:04 -07:00
Kconfig.iosched	blk-cgroup: separate out blkg_rwstat under CONFIG_BLK_CGROUP_RWSTAT	2019-11-07 12:28:13 -07:00
kyber-iosched.c	blk-mq: remove blk_mq_put_ctx()	2019-07-02 21:03:27 -06:00
Makefile	block: merge partition-generic.c and check.c	2020-03-24 07:57:08 -06:00
mq-deadline.c	block: Introduce elevator features	2019-09-05 19:52:33 -06:00
opal_proto.h	block: sed-opal: Change the check condition for regular session validity	2020-03-12 08:00:10 -06:00
scsi_ioctl.c	compat_ioctl: move CDROM_SEND_PACKET handling into scsi	2020-01-03 09:33:05 +01:00
sed-opal.c	block: sed-opal: Change the check condition for regular session validity	2020-03-12 08:00:10 -06:00
t10-pi.c	block: Allow t10-pi to be modular	2020-01-06 20:59:04 -07:00