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Date:   Fri, 30 Sep 2022 19:00:42 -0300
From:   Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
To:     Namhyung Kim <namhyung@kernel.org>, Jiri Olsa <olsajiri@gmail.com>
CC:     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>
Subject: Re: [PATCH] perf stat: Support old kernels for bperf cgroup counting
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On September 30, 2022 6:56:40 PM GMT-03:00, Namhyung Kim <namhyung@kernel=
=2Eorg> wrote:
>Hi Jiri,
>
>On Fri, Sep 30, 2022 at 2:44 PM Jiri Olsa <olsajiri@gmail=2Ecom> 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=2E  It should support both old and new kernels using =
BPF
>> > CO-RE technique=2E
>> >
>> > Like the task_struct->__state handling in the offcpu analysis, we can
>> > check the field name in the cgroup struct=2E
>> >
>> > Signed-off-by: Namhyung Kim <namhyung@kernel=2Eorg>
>> > ---
>> > Arnaldo, I think this should go through the cgroup tree since it depe=
nds
>> > on the earlier change there=2E  I don't think it'd conflict with othe=
r
>> > 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=2Ekernel=2Eorg/pub/scm/linux/kernel/git/tj/cgroup=2Egit
>


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

- Arnaldo=20
>Thanks,=2E
>Namhyung