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 26253463B84 for ; Thu, 27 Aug 2026 14:28:26 +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=1787840909; cv=none; b=hN+A010HSy5dMM+dvsSurb7JxpX4K8AISWlapK4vhhBt8qwXvBfjO+Iov8b5tSJnRdBdXf27rgSpwiiKscnLVfRjpOzlwkxiaz3mHQHB64Ycaenckbx9UNWEUzauzu781gY87tjjN8igKHma7pj6/1XXuROXRPEPzd/lGSjlx5I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787840909; c=relaxed/simple; bh=GKPWKAx2Ce9cFVIbBwR+PvLny99MBRAKKpnyvNv5qmo=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=S6r3Aa2xL4V6GJjErR1Q9kf/fKC/i6o0tlWLWeJvW10mOc9bIFPCosGiUJagcKZ/G7ByupAaN633cgfpadyLcswHpqy4Dzl4puFYzf2ifkBPVII8uCgiscXr86WSHuaTVX9DnekG7+afauXpnbrj2efRzknMRiSShT8Z9suszds= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GSEt8LWn; 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="GSEt8LWn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6B7C01F000E9; Thu, 27 Aug 2026 14:28:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787840903; bh=j9R3r8T6kdR3mi46RIvVT8+9mhwrUSvCrBplIgoCIew=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=GSEt8LWnH6eyVIvGGjFiLrteg6GPNjDgi7e6WUqM5ZwqaLQpdfOx+hEOFI0w8TQdq LxciEANSV8yk5Uu2njFt+UjY9AhDKtTa/0LArbpniQdugMHLTPSokS447Oo5xiGQQy iYBDC9tmmaJ2Ui0QFSfc6f/Zp3ID7iqvqZhPLzezM5KEXLtFI3v8rLZ4dttYIkZ+qM K/CezElivbLAjAm/HOOCTHiqAz7M1/R472cZBtNIGSuCJ7dDw7gYNgWE+g6MGWpto2 oiKHQuOsQRdIDqJaV4KRfp8VmxikQrBPv5Nd2GnhPg9iZZ89qSP9qomvlntO9UwufR 1sF48GRnPHtVA== From: sashiko-bot@kernel.org Subject: Re: [PATCH v2] 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: <20260827-perf_core_fix_zero_aux_records-v2-1-c41f2e7d056c@arm.com> References: <20260827-perf_core_fix_zero_aux_records-v2-1-c41f2e7d056c@arm.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Thu, 27 Aug 2026 14:28:22 +0000 Message-Id: <20260827142823.6B7C01F000E9@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/ { > [ ... ] >=20 > Fixes: 547b60988e63 ("perf: aux: Add flags for the buffer format") > Reported-by: Tamas Petz > Reviewed-by: James Clark > 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/20260827-perf_core_= fix_zero_aux_records-v2-1-c41f2e7d056c@arm.com?part=3D1