diff --git a/Documentation/cgroups/blkio-controller.txt b/Documentation/cgroups/blkio-controller.txt index d422b410a995..48e0b21b0059 100644 --- a/Documentation/cgroups/blkio-controller.txt +++ b/Documentation/cgroups/blkio-controller.txt @@ -17,6 +17,9 @@ HOWTO You can do a very simple testing of running two dd threads in two different cgroups. Here is what you can do. +- Enable Block IO controller + CONFIG_BLK_CGROUP=y + - Enable group scheduling in CFQ CONFIG_CFQ_GROUP_IOSCHED=y @@ -54,25 +57,17 @@ cgroups. Here is what you can do. Various user visible config options =================================== +CONFIG_BLK_CGROUP + - Block IO controller. + +CONFIG_DEBUG_BLK_CGROUP + - Debug help. Right now some additional stats file show up in cgroup + if this option is enabled. + CONFIG_CFQ_GROUP_IOSCHED - Enables group scheduling in CFQ. Currently only 1 level of group creation is allowed. -CONFIG_DEBUG_CFQ_IOSCHED - - Enables some debugging messages in blktrace. Also creates extra - cgroup file blkio.dequeue. - -Config options selected automatically -===================================== -These config options are not user visible and are selected/deselected -automatically based on IO scheduler configuration. - -CONFIG_BLK_CGROUP - - Block IO controller. Selected by CONFIG_CFQ_GROUP_IOSCHED. - -CONFIG_DEBUG_BLK_CGROUP - - Debug help. Selected by CONFIG_DEBUG_CFQ_IOSCHED. - Details of cgroup files ======================= - blkio.weight @@ -174,13 +169,13 @@ Details of cgroup files write, sync or async. - blkio.avg_queue_size - - Debugging aid only enabled if CONFIG_DEBUG_CFQ_IOSCHED=y. + - Debugging aid only enabled if CONFIG_DEBUG_BLK_CGROUP=y. The average queue size for this cgroup over the entire time of this cgroup's existence. Queue size samples are taken each time one of the queues of this cgroup gets a timeslice. - blkio.group_wait_time - - Debugging aid only enabled if CONFIG_DEBUG_CFQ_IOSCHED=y. + - Debugging aid only enabled if CONFIG_DEBUG_BLK_CGROUP=y. This is the amount of time the cgroup had to wait since it became busy (i.e., went from 0 to 1 request queued) to get a timeslice for one of its queues. This is different from the io_wait_time which is the @@ -191,7 +186,7 @@ Details of cgroup files got a timeslice and will not include the current delta. - blkio.empty_time - - Debugging aid only enabled if CONFIG_DEBUG_CFQ_IOSCHED=y. + - Debugging aid only enabled if CONFIG_DEBUG_BLK_CGROUP=y. This is the amount of time a cgroup spends without any pending requests when not being served, i.e., it does not include any time spent idling for one of the queues of the cgroup. This is in @@ -200,7 +195,7 @@ Details of cgroup files time it had a pending request and will not include the current delta. - blkio.idle_time - - Debugging aid only enabled if CONFIG_DEBUG_CFQ_IOSCHED=y. + - Debugging aid only enabled if CONFIG_DEBUG_BLK_CGROUP=y. This is the amount of time spent by the IO scheduler idling for a given cgroup in anticipation of a better request than the exising ones from other queues/cgroups. This is in nanoseconds. If this is read @@ -209,7 +204,7 @@ Details of cgroup files the current delta. - blkio.dequeue - - Debugging aid only enabled if CONFIG_DEBUG_CFQ_IOSCHED=y. This + - Debugging aid only enabled if CONFIG_DEBUG_BLK_CGROUP=y. This gives the statistics about how many a times a group was dequeued from service tree of the device. First two fields specify the major and minor number of the device and third field specifies the number diff --git a/block/Kconfig b/block/Kconfig index f9e89f4d94bb..9be0b56eaee1 100644 --- a/block/Kconfig +++ b/block/Kconfig @@ -77,29 +77,6 @@ config BLK_DEV_INTEGRITY T10/SCSI Data Integrity Field or the T13/ATA External Path Protection. If in doubt, say N. -config BLK_CGROUP - tristate "Block cgroup support" - depends on CGROUPS - depends on CFQ_GROUP_IOSCHED - default n - ---help--- - Generic block IO controller cgroup interface. This is the common - cgroup interface which should be used by various IO controlling - policies. - - Currently, CFQ IO scheduler uses it to recognize task groups and - control disk bandwidth allocation (proportional time slice allocation) - to such task groups. - -config DEBUG_BLK_CGROUP - bool - depends on BLK_CGROUP - default n - ---help--- - Enable some debugging help. Currently it stores the cgroup path - in the blk group which can be used by cfq for tracing various - group related activity. - endif # BLOCK config BLOCK_COMPAT diff --git a/block/Kconfig.iosched b/block/Kconfig.iosched index fc71cf071fb2..3199b76f795d 100644 --- a/block/Kconfig.iosched +++ b/block/Kconfig.iosched @@ -23,7 +23,8 @@ config IOSCHED_DEADLINE config IOSCHED_CFQ tristate "CFQ I/O scheduler" - select BLK_CGROUP if CFQ_GROUP_IOSCHED + # If BLK_CGROUP is a module, CFQ has to be built as module. + depends on (BLK_CGROUP=m && m) || !BLK_CGROUP || BLK_CGROUP=y default y ---help--- The CFQ I/O scheduler tries to distribute bandwidth equally @@ -33,22 +34,15 @@ config IOSCHED_CFQ This is the default I/O scheduler. + Note: If BLK_CGROUP=m, then CFQ can be built only as module. + config CFQ_GROUP_IOSCHED bool "CFQ Group Scheduling support" - depends on IOSCHED_CFQ && CGROUPS + depends on IOSCHED_CFQ && BLK_CGROUP default n ---help--- Enable group IO scheduling in CFQ. -config DEBUG_CFQ_IOSCHED - bool "Debug CFQ Scheduling" - depends on CFQ_GROUP_IOSCHED - select DEBUG_BLK_CGROUP - default n - ---help--- - Enable CFQ IO scheduling debugging in CFQ. Currently it makes - blktrace output more verbose. - choice prompt "Default I/O scheduler" default DEFAULT_CFQ diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index af42efbb0c1d..d02bbf88de13 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -351,10 +351,8 @@ void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg, blkg->blkcg_id = css_id(&blkcg->css); hlist_add_head_rcu(&blkg->blkcg_node, &blkcg->blkg_list); spin_unlock_irqrestore(&blkcg->lock, flags); -#ifdef CONFIG_DEBUG_BLK_CGROUP /* Need to take css reference ? */ cgroup_path(blkcg->css.cgroup, blkg->path, sizeof(blkg->path)); -#endif blkg->dev = dev; } EXPORT_SYMBOL_GPL(blkiocg_add_blkio_group); diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h index a491a6d56ecf..2b866ec1dcea 100644 --- a/block/blk-cgroup.h +++ b/block/blk-cgroup.h @@ -108,10 +108,8 @@ struct blkio_group { void *key; struct hlist_node blkcg_node; unsigned short blkcg_id; -#ifdef CONFIG_DEBUG_BLK_CGROUP /* Store cgroup path */ char path[128]; -#endif /* The device MKDEV(major, minor), this group has been created for */ dev_t dev; @@ -147,6 +145,11 @@ struct blkio_policy_type { extern void blkio_policy_register(struct blkio_policy_type *); extern void blkio_policy_unregister(struct blkio_policy_type *); +static inline char *blkg_path(struct blkio_group *blkg) +{ + return blkg->path; +} + #else struct blkio_group { @@ -158,6 +161,8 @@ struct blkio_policy_type { static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { } static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { } +static inline char *blkg_path(struct blkio_group *blkg) { return NULL; } + #endif #define BLKIO_WEIGHT_MIN 100 @@ -165,10 +170,6 @@ static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { } #define BLKIO_WEIGHT_DEFAULT 500 #ifdef CONFIG_DEBUG_BLK_CGROUP -static inline char *blkg_path(struct blkio_group *blkg) -{ - return blkg->path; -} void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg); void blkiocg_update_dequeue_stats(struct blkio_group *blkg, unsigned long dequeue); @@ -197,7 +198,6 @@ BLKG_FLAG_FNS(idling) BLKG_FLAG_FNS(empty) #undef BLKG_FLAG_FNS #else -static inline char *blkg_path(struct blkio_group *blkg) { return NULL; } static inline void blkiocg_update_avg_queue_size_stats( struct blkio_group *blkg) {} static inline void blkiocg_update_dequeue_stats(struct blkio_group *blkg, diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 002a5b621653..286008cf889e 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -345,7 +345,7 @@ CFQ_CFQQ_FNS(deep); CFQ_CFQQ_FNS(wait_busy); #undef CFQ_CFQQ_FNS -#ifdef CONFIG_DEBUG_CFQ_IOSCHED +#ifdef CONFIG_CFQ_GROUP_IOSCHED #define cfq_log_cfqq(cfqd, cfqq, fmt, args...) \ blk_add_trace_msg((cfqd)->queue, "cfq%d%c %s " fmt, (cfqq)->pid, \ cfq_cfqq_sync((cfqq)) ? 'S' : 'A', \ diff --git a/init/Kconfig b/init/Kconfig index eb77e8ccde1c..087c14f3c595 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -612,6 +612,33 @@ config RT_GROUP_SCHED endif #CGROUP_SCHED +config BLK_CGROUP + tristate "Block IO controller" + depends on CGROUPS && BLOCK + default n + ---help--- + Generic block IO controller cgroup interface. This is the common + cgroup interface which should be used by various IO controlling + policies. + + Currently, CFQ IO scheduler uses it to recognize task groups and + control disk bandwidth allocation (proportional time slice allocation) + to such task groups. + + This option only enables generic Block IO controller infrastructure. + One needs to also enable actual IO controlling logic in CFQ for it + to take effect. (CONFIG_CFQ_GROUP_IOSCHED=y). + + See Documentation/cgroups/blkio-controller.txt for more information. + +config DEBUG_BLK_CGROUP + bool "Enable Block IO controller debugging" + depends on BLK_CGROUP + default n + ---help--- + Enable some debugging help. Currently it exports additional stat + files in a cgroup which can be useful for debugging. + endif # CGROUPS config MM_OWNER