From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 930A5394EB7 for ; Tue, 25 Aug 2026 10:44:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787654682; cv=none; b=Tmhz3HFxa/eUgVl+nXPLvY2lGWY+0nlNV0JVSjbIQjPT2LiO30du1bGFbKBOiNFtW6K5mk0mjvFQzxxEbTQZEppTIqAUcEKBfS0ayWy2UV/U17xgp0655G19rVwKYJ6snEXERLeLHuX6fNvmYD4RULMn8l4f+3pKJNDemOUmB90= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787654682; c=relaxed/simple; bh=7I03Aeu8emq7hINk9TeWO/6Ang/IZIAD+VxuZOpjwXQ=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=Gt0O+LPZHtrklbUzNOCaoA3tcMlzkGUbmjvJ4BJIe1yfiRUVlrESb7u2iy/vgb2XQoYVBiyx5Qp27RMBdss+diAO5prOiyM+B+tnu2HEzHou3154ay7ohuNCCJNWI3fh6ca5v08FXpLcWjIrZ48CtWPYZyI5V/oolKwew8PQ1ic= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=a1QJQ9f0; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="a1QJQ9f0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 12E161F00A3A; Tue, 25 Aug 2026 10:44:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787654681; bh=qJQ74P4OAIazVDQo0YFfQFiYz57jBP7q024QsTbDypE=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=a1QJQ9f096LGI0soEyK5+FpxfFC8eY1tQv2zTZeNsuzUiqobWjpC9/OMyPT5O2IXq 9J750xTW61ids6p8drATNXVx7SnWuvtQujlyItu9x3IhhiTMTeF8eHh7GE207FMk0Z zSYELUnsN/qEWTMLa8xPLOKJwnOeWUCO9Myb6GAWlMpm/N99geUCobKxV3TRRr7kT3 t/av+rea9aKgvKvFpCJ5YN+MfjsWTQRjAJk5DLoXP4+rFZSzVfRWzrQ7DCJNXR2HrO 8obTAJTIuOuxCZB+KWEmnK8C7sel7rrbRwUdb14KrO3/3TP7gqaiiylJqe3Vd0m2gs UI4aob1zygLqw== From: sashiko-bot@kernel.org Subject: Re: [PATCH] perf/core: Skip empty AUX records with only format flags Reply-To: sashiko-reviews@lists.linux.dev To: "Leo Yan" Cc: linux-perf-users@vger.kernel.org In-Reply-To: <20260825-perf_core_fix_zero_aux_records-v1-1-23b95e8d5df3@arm.com> References: <20260825-perf_core_fix_zero_aux_records-v1-1-23b95e8d5df3@arm.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 25 Aug 2026 10:44:40 +0000 Message-Id: <20260825104441.12E161F00A3A@smtp.kernel.org> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > perf_aux_output_end() emits a PERF_RECORD_AUX when the recorded size is > nonzero or when any flag other than PERF_AUX_FLAG_OVERWRITE is set. >=20 > PMU format flags describe how an AUX payload is encoded. TRBE driver > sets PERF_AUX_FLAG_CORESIGHT_FORMAT_RAW for raw trace buffers, causing > an AUX record to be emitted even when no trace data. >=20 > This is noticeable when tracing a task with strace. Ptrace stops > repeatedly end empty AUX transactions, producing many zero-sized > PERF_RECORD_AUX records. For example: >=20 > perf record -e cs_etm//u -m,128M -- strace ls >=20 > perf script -D 2>&1 | > awk '/PERF_RECORD_AUX offset/ { > [ ... ] > are still emitted. >=20 > Fixes: 547b60988e63 ("perf: aux: Add flags for the buffer format") > Reported-by: Tamas Petz > Signed-off-by: Leo Yan Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260825-perf_core_= fix_zero_aux_records-v1-1-23b95e8d5df3@arm.com?part=3D1