Re: [RFC 1/2] perf core: Add PERF_COUNT_SW_CGROUP_SWITCHES event

[Stephane Eranian]

On Wed, Dec 2, 2020 at 11:28 AM Andi Kleen <ak@xxxxxxxxxxxxxxx> wrote:
>
> > +     prev_cgrp = task_css_check(prev, perf_event_cgrp_id, 1)->cgroup;
> > +     next_cgrp = task_css_check(next, perf_event_cgrp_id, 1)->cgroup;
> > +
> > +     if (prev_cgrp != next_cgrp)
> > +             perf_sw_event_sched(PERF_COUNT_SW_CGROUP_SWITCHES, 1, 0);
>
> Seems to be the perf cgroup only, not all cgroups.
> That's a big difference and needs to be documented properly.
>
We care about the all-cgroup case.

> Probably would make sense to have two events for both, one for
> all cgroups and one for perf only.
>
>
>
> -Andi