Re: [PATCH v2] perf tools: Get a perf cgroup more portably in BPF

[Hao Luo]

On Wed, Sep 21, 2022 at 9:40 PM Namhyung Kim <namhyung@xxxxxxxxxx> wrote:
>
> The perf_event_cgrp_id can be different on other configurations.
> To be more portable as CO-RE, it needs to get the cgroup subsys id
> using the bpf_core_enum_value() helper.
>

I remember using bpf_core_enum_value requires a compiler built-in. So
the build will fail on old compiler such as clang-11. See [1]. Maybe
we should surround it with #if
__has_builtin(__builtin_preserve_enum_value) to be sure.

[1]  https://www.spinics.net/lists/bpf/msg30859.html

> Suggested-by: Ian Rogers <irogers@xxxxxxxxxx>
> Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
> ---
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