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authorRusty Russell <rusty@rustcorp.com.au>2008-12-13 21:55:51 +1030
committerRusty Russell <rusty@rustcorp.com.au>2008-12-13 21:55:51 +1030
commit968ea6d80e395cf11a51143cfa1b9a14ada676df (patch)
treedc2acec8c9bdced33afe1e273ee5e0b0b93d2703 /Documentation/controllers/cpuacct.txt
parent7be7585393d311866653564fbcd10a3232773c0b (diff)
parent8299608f140ae321e4eb5d1306184265d2b9511e (diff)
Merge ../linux-2.6-x86
Conflicts: arch/x86/kernel/io_apic.c kernel/sched.c kernel/sched_stats.h
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+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.