diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/controllers/cpuacct.txt | 32 | ||||
| -rw-r--r-- | Documentation/scheduler/sched-arch.txt | 4 |
2 files changed, 34 insertions, 2 deletions
diff --git a/Documentation/controllers/cpuacct.txt b/Documentation/controllers/cpuacct.txt new file mode 100644 index 00000000000..bb775fbe43d --- /dev/null +++ b/Documentation/controllers/cpuacct.txt @@ -0,0 +1,32 @@ +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. diff --git a/Documentation/scheduler/sched-arch.txt b/Documentation/scheduler/sched-arch.txt index 941615a9769..d43dbcbd163 100644 --- a/Documentation/scheduler/sched-arch.txt +++ b/Documentation/scheduler/sched-arch.txt @@ -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. |