From nobody Fri Dec 19 00:34:46 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 64146647; Thu, 10 Apr 2025 01:02:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744246974; cv=none; b=UzP4uFNHJrx9fB9Hy9+qkxUr++vvYqhd0fmSaqGiavtpcib7P+1bxdb3Ezr9ln2nuRE2zycowcIsw5LuOHEyP0cmdRx0eDL7C1mcpSblX2HTevRS4oiZSeRnrxniUvx7aivS0jQSOL4NAvNccxTiqnqYujcZxe9qI9ac7ubOrrs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744246974; c=relaxed/simple; bh=GUHS/4Nkf7J6bc7/7YtgtSPyEUMQRZos6or8dxKDCvQ=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=JyXWvMAvizcBjgRrD41+7JSOI6dyUSf3NZbP+CuptArLzmtgiOcvrNXBvkh9MPuENd40/pKc3wo7qnOvnsl8y0hLvuJui8thXsRaxjMzQ9JCiDs45Zx8l7P7w/NBT0WxPJ76hBph/ft+YycLU4jrUULYR6MjizG1b618b7JK9uU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=rCSrbdm8; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="rCSrbdm8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7BDAEC4CEE2; Thu, 10 Apr 2025 01:02:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1744246973; bh=GUHS/4Nkf7J6bc7/7YtgtSPyEUMQRZos6or8dxKDCvQ=; h=From:To:Cc:Subject:Date:From; b=rCSrbdm8YmhBLINvMRhxVXHCpPNnvfykqKlQtSIHktdCfth7lajVgWPG3zsSD9Uvo ASE46zXUJeClhsnDjswyNvVEtnqEl6OkLS+FauYQb0Vb8gsiQxwdpxhjp+zo6E3NWa RemXsDCBo7aSgIMABbqxgvevCecfwSV0UcACo9598cRYzEYtmlLOEeTvT52JUA8Ib7 QkZQFEAX+15BOjYDd7FuNkhcAW1/3KRJjxDb0IBYGUUBFGJk6TwCHSliI5nenqdvKu Azl3pukIGnawwxF+8BjHivYHrVEZkYFcEW55I3A1Ys0/Kr8rHDVP8H8AjMWTeB+NlT s3ldob5jriWbQ== From: Namhyung Kim To: Arnaldo Carvalho de Melo , Ian Rogers , Kan Liang Cc: Jiri Olsa , Adrian Hunter , Peter Zijlstra , Ingo Molnar , LKML , linux-perf-users@vger.kernel.org, Chun-Tse Shao , Ravi Bangoria Subject: [PATCH] perf tools: Remove evsel__handle_error_quirks() Date: Wed, 9 Apr 2025 18:02:52 -0700 Message-ID: <20250410010252.402221-1-namhyung@kernel.org> X-Mailer: git-send-email 2.49.0.504.g3bcea36a83-goog Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The evsel__handle_error_quirks() is to fixup invalid event attributes on some architecture based on the error code. Currently it's only used for AMD to disable precise_ip not to use IBS which has more restrictions. But the commit c33aea446bf555ab changed call evsel__precise_ip_fallback for any errors so there's no difference with the above function. To make matter worse, it caused a problem with branch stack on Zen3. The IBS doesn't support branch stack so it should use a regular core PMU event. The default event is set precise_max and it starts with 3. And evsel__precise_ip_fallback() tries with it and reduces the level one by one. At last it tries with 0 but it also failed on Zen3 since the branch stack is not supported for the cycles event. At this point, evsel__precise_ip_fallback() restores the original precise_ip value (3) in the hope that it can succeed with other modifier (like exclude_kernel). Then evsel__handle_error_quirks() see it has precise_ip !=3D 0 and make it retry with 0. This created an infinite loop. Before: $ perf record -b -vv |& grep removing removing precise_ip on AMD removing precise_ip on AMD removing precise_ip on AMD removing precise_ip on AMD removing precise_ip on AMD removing precise_ip on AMD removing precise_ip on AMD removing precise_ip on AMD removing precise_ip on AMD removing precise_ip on AMD removing precise_ip on AMD removing precise_ip on AMD ... After: $ perf record -b true Error: Failure to open event 'cycles:P' on PMU 'cpu' which will be removed. Invalid event (cycles:P) in per-thread mode, enable system wide with '-a'. Error: Failure to open any events for recording. Fixes: c33aea446bf555ab ("perf tools: Fix precise_ip fallback logic") Cc: Ravi Bangoria Signed-off-by: Namhyung Kim Tested-by: Chun-Tse Shao --- tools/perf/util/evsel.c | 22 ---------------------- 1 file changed, 22 deletions(-) diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index 1974395492d7da5e..3c030da2e477c707 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -2566,25 +2566,6 @@ static bool evsel__detect_missing_features(struct ev= sel *evsel, struct perf_cpu return false; } =20 -static bool evsel__handle_error_quirks(struct evsel *evsel, int error) -{ - /* - * AMD core PMU tries to forward events with precise_ip to IBS PMU - * implicitly. But IBS PMU has more restrictions so it can fail with - * supported event attributes. Let's forward it back to the core PMU - * by clearing precise_ip only if it's from precise_max (:P). - */ - if ((error =3D=3D -EINVAL || error =3D=3D -ENOENT) && x86__is_amd_cpu() && - evsel->core.attr.precise_ip && evsel->precise_max) { - evsel->core.attr.precise_ip =3D 0; - pr_debug2_peo("removing precise_ip on AMD\n"); - display_attr(&evsel->core.attr); - return true; - } - - return false; -} - static int evsel__open_cpu(struct evsel *evsel, struct perf_cpu_map *cpus, struct perf_thread_map *threads, int start_cpu_map_idx, int end_cpu_map_idx) @@ -2730,9 +2711,6 @@ static int evsel__open_cpu(struct evsel *evsel, struc= t perf_cpu_map *cpus, if (evsel__precise_ip_fallback(evsel)) goto retry_open; =20 - if (evsel__handle_error_quirks(evsel, err)) - goto retry_open; - out_close: if (err) threads->err_thread =3D thread; --=20 2.49.0.504.g3bcea36a83-goog