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

Jiri Olsa
2022-10-01T13:57:54Z

On Fri, Sep 30, 2022 at 02:56:40PM -0700, Namhyung Kim wrote:
> Hi Jiri,
>
> On Fri, Sep 30, 2022 at 2:44 PM Jiri Olsa <olsajiri-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> 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-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> > > ---
> > > 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!
> >
> > could you please paste the cgroup tree link?
>
> Do you mean this?
>
> https://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git

yea, wanted to try that.. I cherry-picked the 7f203bc89eb6 ;-)

thanks,
jirka

>
> Thanks,.
> Namhyung