lkml.org 
[lkml]   [2012]   [Oct]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH] perf cgroups: Fix perf_cgroup_switch schedule in warning
From
On Tue, Oct 2, 2012 at 2:39 PM, Jiri Olsa <jolsa@redhat.com> wrote:
> On Tue, Oct 02, 2012 at 01:53:01PM +0200, Peter Zijlstra wrote:
>> On Tue, 2012-10-02 at 13:42 +0200, Jiri Olsa wrote:
>> > +++ b/kernel/events/core.c
>> > @@ -394,7 +394,8 @@ void perf_cgroup_switch(struct task_struct *task, int mode)
>> > }
>> >
>> > if (mode & PERF_CGROUP_SWIN) {
>> > - WARN_ON_ONCE(cpuctx->cgrp);
>> > + WARN_ON_ONCE(cpuctx->cgrp && !cpuctx->ctx.is_active);
>> > +
>> > /* set cgrp before ctxsw in to
>> > * allow event_filter_match() to not
>> > * have to pass task around
>>
>> OK, like you mentioned this is the result of multiple PMU being able to
>> share a cpuctx, shouldn't we in that case avoid the second loop over the
>> cpuctx as a whole?
>>
Not sure, I understand what active_pmu represents.

>> Would something like the below do? IIRC I introduced that active_pmu for
>> exactly such reasons..
>>
>> ---
>> kernel/events/core.c | 2 ++
>> 1 file changed, 2 insertions(+)
>>
>> diff --git a/kernel/events/core.c b/kernel/events/core.c
>> index 7b9df35..e98f014 100644
>> --- a/kernel/events/core.c
>> +++ b/kernel/events/core.c
>> @@ -372,6 +372,8 @@ void perf_cgroup_switch(struct task_struct *task, int mode)
>>
>> list_for_each_entry_rcu(pmu, &pmus, entry) {
>> cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
>> + if (cpuctx->active_pmu != pmu)
>> + continue;
>>
>> /*
>> * perf_cgroup_events says at least one
>>
>
> this passed my test
>
> jirka


\
 
 \ /
  Last update: 2012-10-02 15:21    [W:0.134 / U:0.060 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site