Commit-ID: e3c8ca8336707062f3f7cb1cd7e6b3c753baccdd Gitweb: http://git.kernel.org/tip/e3c8ca8336707062f3f7cb1cd7e6b3c753baccdd Author: Nathan Lynch <ntl@xxxxxxxxx> AuthorDate: Wed, 8 Apr 2009 19:45:12 -0500 Committer: Ingo Molnar <mingo@xxxxxxx> CommitDate: Thu, 9 Apr 2009 07:37:02 +0200 sched: do not count frozen tasks toward load Freezing tasks via the cgroup freezer causes the load average to climb because the freezer's current implementation puts frozen tasks in uninterruptible sleep (D state). Some applications which perform job-scheduling functions consult the load average when making decisions. If a cgroup is frozen, the load average does not provide a useful measure of the system's utilization to such applications. This is especially inconvenient if the job scheduler employs the cgroup freezer as a mechanism for preempting low priority jobs. Contrast this with using SIGSTOP for the same purpose: the stopped tasks do not count toward system load. Change task_contributes_to_load() to return false if the task is frozen. This results in /proc/loadavg behavior that better meets users' expectations. Signed-off-by: Nathan Lynch <ntl@xxxxxxxxx> Acked-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Acked-by: Nigel Cunningham <nigel@xxxxxxxxxxxx> Tested-by: Nigel Cunningham <nigel@xxxxxxxxxxxx> Cc: <stable@xxxxxxxxxx> Cc: containers@xxxxxxxxxxxxxxxxxxxxxxxxxx Cc: linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx Cc: Matt Helsley <matthltc@xxxxxxxxxx> LKML-Reference: <20090408194512.47a99b95@xxxxxxxxxxx> Signed-off-by: Ingo Molnar <mingo@xxxxxxx> --- include/linux/sched.h | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 98e1fe5..b4c38bc 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -205,7 +205,8 @@ extern unsigned long long time_sync_thresh; #define task_is_stopped_or_traced(task) \ ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0) #define task_contributes_to_load(task) \ - ((task->state & TASK_UNINTERRUPTIBLE) != 0) + ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \ + (task->flags & PF_FROZEN) == 0) #define __set_task_state(tsk, state_value) \ do { (tsk)->state = (state_value); } while (0) -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html