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From:   Namhyung Kim <namhyung@kernel.org>
Date:   Fri, 30 Sep 2022 15:11:02 -0700
Message-ID: <CAM9d7ci4mvc1rsMyRbwH-i2=8XVsEAvkk5JXLMHmbV4nkbBYhQ@mail.gmail.com>
Subject: Re: [PATCH] perf stat: Support old kernels for bperf cgroup counting
To:     Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
Cc:     Jiri Olsa <olsajiri@gmail.com>, Tejun Heo <tj@kernel.org>,
        Zefan Li <lizefan.x@bytedance.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        cgroups <cgroups@vger.kernel.org>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        linux-perf-users <linux-perf-users@vger.kernel.org>,
        Song Liu <songliubraving@fb.com>, bpf <bpf@vger.kernel.org>
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On Fri, Sep 30, 2022 at 3:00 PM Arnaldo Carvalho de Melo
<arnaldo.melo@gmail.com> wrote:
>
>
>
> 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?

I believe it's for-6.1 and the cset is in

  https://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git/commit/?h=for-6.1&id=7f203bc89eb66d6afde7eae91347fc0352090cc3

Thanks,
Namhyung