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

From: Namhyung Kim
Date: Fri Sep 30 2022 - 17:56:57 EST


Hi Jiri,

On Fri, Sep 30, 2022 at 2:44 PM Jiri Olsa <olsajiri@xxxxxxxxx> 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!
>
> could you please paste the cgroup tree link?

Do you mean this?

https://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git

Thanks,.
Namhyung