blk-cgroup: config options re-arrangement

[safe/jmp/linux-2.6] / Documentation / cgroups / blkio-controller.txt

diff --git a/Documentation/cgroups/blkio-controller.txt b/Documentation/cgroups/blkio-controller.txt
index d422b41..48e0b21 100644 (file)
--- 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