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Commit a39b8633 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'sched-core-for-linus' of...

Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (31 commits)
  sched: fix warning in fs/proc/base.c
  schedstat: consolidate per-task cpu runtime stats
  sched: use RCU variant of list traversal in for_each_leaf_rt_rq()
  sched, cpuacct: export percpu cpuacct cgroup stats
  sched, cpuacct: refactoring cpuusage_read / cpuusage_write
  sched: optimize update_curr()
  sched: fix wakeup preemption clock
  sched: add missing arch_update_cpu_topology() call
  sched: let arch_update_cpu_topology indicate if topology changed
  sched: idle_balance() does not call load_balance_newidle()
  sched: fix sd_parent_degenerate on non-numa smp machine
  sched: add uid information to sched_debug for CONFIG_USER_SCHED
  sched: move double_unlock_balance() higher
  sched: update comment for move_task_off_dead_cpu
  sched: fix inconsistency when redistribute per-cpu tg->cfs_rq shares
  sched/rt: removed unneeded defintion
  sched: add hierarchical accounting to cpu accounting controller
  sched: include group statistics in /proc/sched_debug
  sched: rename SCHED_NO_NO_OMIT_FRAME_POINTER => SCHED_OMIT_FRAME_POINTER
  sched: clean up SCHED_CPUMASK_ALLOC
  ...
parents b0f4b285 4e202284
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+32 −0
Original line number Diff line number Diff line
CPU Accounting Controller
-------------------------

The CPU accounting controller is used to group tasks using cgroups and
account the CPU usage of these groups of tasks.

The CPU accounting controller supports multi-hierarchy groups. An accounting
group accumulates the CPU usage of all of its child groups and the tasks
directly present in its group.

Accounting groups can be created by first mounting the cgroup filesystem.

# mkdir /cgroups
# mount -t cgroup -ocpuacct none /cgroups

With the above step, the initial or the parent accounting group
becomes visible at /cgroups. At bootup, this group includes all the
tasks in the system. /cgroups/tasks lists the tasks in this cgroup.
/cgroups/cpuacct.usage gives the CPU time (in nanoseconds) obtained by
this group which is essentially the CPU time obtained by all the tasks
in the system.

New accounting groups can be created under the parent group /cgroups.

# cd /cgroups
# mkdir g1
# echo $$ > g1

The above steps create a new group g1 and move the current shell
process (bash) into it. CPU time consumed by this bash and its children
can be obtained from g1/cpuacct.usage and the same is accumulated in
/cgroups/cpuacct.usage also.
+2 −2
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@@ -8,7 +8,7 @@ Context switch
By default, the switch_to arch function is called with the runqueue
locked. This is usually not a problem unless switch_to may need to
take the runqueue lock. This is usually due to a wake up operation in
the context switch. See include/asm-ia64/system.h for an example.
the context switch. See arch/ia64/include/asm/system.h for an example.

To request the scheduler call switch_to with the runqueue unlocked,
you must `#define __ARCH_WANT_UNLOCKED_CTXSW` in a header file
@@ -23,7 +23,7 @@ disabled. Interrupts may be enabled over the call if it is likely to
introduce a significant interrupt latency by adding the line
`#define __ARCH_WANT_INTERRUPTS_ON_CTXSW` in the same place as for
unlocked context switches. This define also implies
`__ARCH_WANT_UNLOCKED_CTXSW`. See include/asm-arm/system.h for an
`__ARCH_WANT_UNLOCKED_CTXSW`. See arch/arm/include/asm/system.h for an
example.


+1 −1
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@@ -99,7 +99,7 @@ config GENERIC_IOMAP
	bool
	default y

config SCHED_NO_NO_OMIT_FRAME_POINTER
config SCHED_OMIT_FRAME_POINTER
	bool
	default y

+1 −1
Original line number Diff line number Diff line
@@ -273,7 +273,7 @@ config GENERIC_CALIBRATE_DELAY
	bool
	default y

config SCHED_NO_NO_OMIT_FRAME_POINTER
config SCHED_OMIT_FRAME_POINTER
        bool
        default y

+1 −1
Original line number Diff line number Diff line
@@ -653,7 +653,7 @@ config GENERIC_CMOS_UPDATE
	bool
	default y

config SCHED_NO_NO_OMIT_FRAME_POINTER
config SCHED_OMIT_FRAME_POINTER
	bool
	default y

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