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Date: Wed, 15 May 2024 10:58:40 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Namhyung Kim <namhyung@kernel.org>
Cc: Yabin Cui <yabinc@google.com>, 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>,
	Jiri Olsa <jolsa@kernel.org>, Ian Rogers <irogers@google.com>,
	Adrian Hunter <adrian.hunter@intel.com>,
	linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
	bpf@vger.kernel.org
Subject: Re: [PATCH v4 3/3] perf/core: Check sample_type in
 perf_sample_save_brstack
Message-ID: <20240515085840.GD40213@noisy.programming.kicks-ass.net>
References: <20240510191423.2297538-1-yabinc@google.com>
 <20240510191423.2297538-4-yabinc@google.com>
 <CAM9d7chNz8-84m28q5qSLjUjZ=Ni1CA_JzbB_P+YJooLQd85YA@mail.gmail.com>
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On Fri, May 10, 2024 at 02:29:58PM -0700, Namhyung Kim wrote:
> On Fri, May 10, 2024 at 12:14 PM Yabin Cui <yabinc@google.com> wrote:
> >
> > Check sample_type in perf_sample_save_brstack() to prevent
> > saving branch stack data when it isn't required.
> >
> > Suggested-by: Namhyung Kim <namhyung@kernel.org>
> > Signed-off-by: Yabin Cui <yabinc@google.com>
> 
> It seems powerpc has the similar bug, then you need this:
> 
> Fixes: eb55b455ef9c ("perf/core: Add perf_sample_save_brstack() helper")

Is this really a bug? AFAICT it just does unneeded work, no?