Hi again. On Wed, 2009-04-08 at 19:45 -0500, Nathan Lynch wrote: > 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 <[email protected]> > --- > 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 011db2f..f8af167 100644 > --- a/include/linux/sched.h > +++ b/include/linux/sched.h > @@ -202,7 +202,8 @@ 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)
Tested-by: Nigel Cunningham <[email protected]> Looks good to me (though I like Andrew's point about using task_frozen). ni...@nigel-laptop:~$ cat /proc/loadavg 0.34 0.27 0.12 1/251 9001 ni...@nigel-laptop:~$ sudo hibernate ni...@nigel-laptop:~$ cat /proc/loadavg 0.52 0.33 0.14 2/250 9807 ni...@nigel-laptop:~$ _______________________________________________ Containers mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/containers _______________________________________________ Devel mailing list [email protected] https://openvz.org/mailman/listinfo/devel
