Re: [PATCH] perf stat: Support old kernels for bperf cgroup counting

[Namhyung Kim]

On Fri, Sep 23, 2022 at 8:22 PM Tejun Heo <tj@xxxxxxxxxx> wrote:
>
> On Wed, Sep 21, 2022 at 09:14:35PM -0700, Namhyung Kim wrote:
> > The recent change in the cgroup will break the backward compatiblity in
> > the BPF program.  It should support both old and new kernels using BPF
> > CO-RE technique.
> >
> > Like the task_struct->__state handling in the offcpu analysis, we can
> > check the field name in the cgroup struct.
> >
> > Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
> > ---
> > Arnaldo, I think this should go through the cgroup tree since it depends
> > on the earlier change there.  I don't think it'd conflict with other
> > perf changes but please let me know if you see any trouble, thanks!
>
> FWIW, looks fine to me and I'd be happy to route this through the cgroup
> tree once it gets acked.

Thanks Tejun!

Can any perf + bpf folks take a look?