Re: [PATCHSET v2 0/3] perf stat: Enable BPF counters with --for-each-cgroup

[Namhyung Kim]

Hi Peter,

On Wed, Jun 16, 2021 at 8:14 AM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>
> On Mon, Jun 14, 2021 at 06:17:21PM -0700, Namhyung Kim wrote:
> > Current limitations are:
> >  * it doesn't support cgroup hierarchy
>
> That seems unfortunate; there's no bpf helper to iterate cgroup
> hierarchy?

I couldn't find one..

>
> >  * there's no reliable way to trigger running the BPF program
>
> You can't attach to the PERF_COUNT_SW_CGROUP_SWITCHES event?

I did it.  But the BPF test run seems not to work with perf_event.
So it needs to trigger a cgroup switch manually..

Thanks,
Namhyung