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

Arnaldo Carvalho de Melo
2022-09-30T22:00:42Z

On September 30, 2022 6:56:40 PM GMT-03:00, Namhyung Kim <namhyung@kernel.org> wrote:
>Hi Jiri,
>
>On Fri, Sep 30, 2022 at 2:44 PM Jiri Olsa <olsajiri@gmail.com> 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@kernel.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
>

Which branch and cset in that tree does you perf skel depends on?

- Arnaldo
>Thanks,.
>Namhyung