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References: <20231211045543.31741-1-khuey@kylehuey.com> <20231211045543.31741-2-khuey@kylehuey.com>
In-Reply-To: <20231211045543.31741-2-khuey@kylehuey.com>
From: Song Liu <song@kernel.org>
Date: Tue, 2 Jan 2024 14:56:03 -0800
Message-ID: <CAPhsuW6VqD=zie6Y6JPALp3egMSYWF6UysS+bQG_61t=6v4fxQ@mail.gmail.com>
Subject: Re: [PATCH v3 1/4] perf/bpf: Call bpf handler directly, not through
 overflow machinery
To: Kyle Huey <me@kylehuey.com>
Cc: Kyle Huey <khuey@kylehuey.com>, linux-kernel@vger.kernel.org, 
	Andrii Nakryiko <andrii.nakryiko@gmail.com>, Jiri Olsa <jolsa@kernel.org>, 
	Namhyung Kim <namhyung@kernel.org>, Marco Elver <elver@google.com>, 
	Yonghong Song <yonghong.song@linux.dev>, "Robert O'Callahan" <robert@ocallahan.org>, 
	Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@redhat.com>, 
	Arnaldo Carvalho de Melo <acme@kernel.org>, Mark Rutland <mark.rutland@arm.com>, 
	Alexander Shishkin <alexander.shishkin@linux.intel.com>, Ian Rogers <irogers@google.com>, 
	Adrian Hunter <adrian.hunter@intel.com>, linux-perf-users@vger.kernel.org, 
	bpf@vger.kernel.org
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On Sun, Dec 10, 2023 at 8:55=E2=80=AFPM Kyle Huey <me@kylehuey.com> wrote:
>
> To ultimately allow bpf programs attached to perf events to completely
> suppress all of the effects of a perf event overflow (rather than just th=
e
> sample output, as they do today), call bpf_overflow_handler() from
> __perf_event_overflow() directly rather than modifying struct perf_event'=
s
> overflow_handler. Return the bpf program's return value from
> bpf_overflow_handler() so that __perf_event_overflow() knows how to
> proceed. Remove the now unnecessary orig_overflow_handler from struct
> perf_event.
>
> This patch is solely a refactoring and results in no behavior change.
>
> Signed-off-by: Kyle Huey <khuey@kylehuey.com>
> Suggested-by: Namhyung Kim <namhyung@kernel.org>

Acked-by: Song Liu <song@kernel.org>