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-rw-r--r--Documentation/cgroups/blkio-controller.txt35
-rw-r--r--block/Kconfig23
-rw-r--r--block/Kconfig.iosched16
-rw-r--r--block/blk-cgroup.c2
-rw-r--r--block/blk-cgroup.h14
-rw-r--r--block/cfq-iosched.c2
-rw-r--r--init/Kconfig27
7 files changed, 55 insertions, 64 deletions
diff --git a/Documentation/cgroups/blkio-controller.txt b/Documentation/cgroups/blkio-controller.txt
index d422b41..48e0b21 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
@@ -54,24 +57,16 @@ cgroups. Here is what you can do.
Various user visible config options
===================================
-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.
+ - Block IO controller.
CONFIG_DEBUG_BLK_CGROUP
- - Debug help. Selected by CONFIG_DEBUG_CFQ_IOSCHED.
+ - 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.
Details of cgroup files
=======================
@@ -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 f9e89f4..9be0b56 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 fc71cf07..3199b76 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 af42efb..d02bbf8 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 a491a6d..2b866ec 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 002a5b6..286008c 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 eb77e8c..087c14f 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