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Date:   Fri, 14 Oct 2022 10:27:40 -0300
From:   Arnaldo Carvalho de Melo <acme@kernel.org>
To:     Tejun Heo <tj@kernel.org>
Cc:     Namhyung Kim <namhyung@kernel.org>,
        Zefan Li <lizefan.x@bytedance.com>,
        Johannes Weiner <hannes@cmpxchg.org>, cgroups@vger.kernel.org,
        Jiri Olsa <jolsa@kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        linux-perf-users@vger.kernel.org, Song Liu <songliubraving@fb.com>,
        bpf@vger.kernel.org, Andrii Nakryiko <andrii@kernel.org>
Subject: Re: [PATCH v2] perf stat: Support old kernels for bperf cgroup
 counting
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Em Tue, Oct 11, 2022 at 06:53:43AM -1000, Tejun Heo escreveu:
> On Mon, Oct 10, 2022 at 10:28:08PM -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.
 
> > Acked-by: Jiri Olsa <jolsa@kernel.org>
> > Acked-by: Andrii Nakryiko <andrii@kernel.org>
> > Signed-off-by: Namhyung Kim <namhyung@kernel.org>
 
> Applied to cgroup/for-6.1-fixes.

Hey, I noticed that the perf build is broken for the
tools/perf/util/bpf_skel/bperf_cgroup.bpf.c skell, so I tried using b4
on this Namhyung patch, it ended up getting a newer version, by Tejun,
that mixes up kernel code and tooling, which, when I tried to apply
upstream didn't work.

Please try not to mix up kernel and tools/ changes in the same patch to
avoid these issues.

Also when changing tools/perf, please CC me.

I'm now back trying to apply v2 of this patch to see if it fixes my
build.

Thanks,

- Arnaldo