From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 3BC7B3DF018; Thu, 4 Jun 2026 08:20:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780561255; cv=none; b=Q4Ykkk1xyLeIWopnWgIt5OIRiqiEGiFjWYLbzgiMWTRXXzPUEuFVlmgQihQmzFrH9Fva/5bNnhU0wbaMuAtITBFv4MixRR7vr3qv0cyFo7dxVE4k+ZJVxAv1AFOmJxFdNNyd2OF2KP6YwHqFVwWypm1XSv+zAwaYnJ9dF3eRcws= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780561255; c=relaxed/simple; bh=xx4q8zA0SDvN+Zn0mJt/nZF2yaNi8H3ZSogpxfNtLDY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=cxmrrBWyt13HEk2ybD/bqePQ/X8JGkUnUiZoJOrxyGt+gTdF1L8WYexop23KXSK3IAL81cAhHhIlx1fVHWJrDBoWDM4n1z4c2cJqsFZSmtPsEhlMKW98WHI8I/AkS1L5JlbEbytW6aAjPIA/KSnH9VcVJmGtHP63RAhrz4QpU8U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=HBXd5CG+; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="HBXd5CG+" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A3D013297; Thu, 4 Jun 2026 01:20:45 -0700 (PDT) Received: from localhost (e132581.arm.com [10.1.196.87]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id EE7FD3F7D8; Thu, 4 Jun 2026 01:20:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1780561250; bh=xx4q8zA0SDvN+Zn0mJt/nZF2yaNi8H3ZSogpxfNtLDY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=HBXd5CG+Kw6LL3Z4p7LfEbspjPtluKqFtPwlqSvB7gMo+FkOMRXEUzIzw8YIkodTH 5cfr6vGu5hfm2waGS4loALDrp8AsIwkxiZPthmIUwEjoK01BV2uy+NuQT4FHx7Zp2C 2NcAeygFzCwWLdxy4tNOTyHo+5qDb5CzLEAqoEHA= Date: Thu, 4 Jun 2026 09:20:47 +0100 From: Leo Yan To: Amir Ayupov Cc: James Clark , stable@vger.kernel.org, Suzuki K Poulose , Mike Leach , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , John Garry , Will Deacon , coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] perf cs-etm: stamp pid/tid/EL on each buffered packet to fix cross-pid attribution Message-ID: <20260604082047.GL101133@e132581.arm.com> References: <20260515021135.1729028-1-aaupov@meta.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Hi Amir, On Wed, Jun 03, 2026 at 01:10:17PM -0700, Amir Ayupov wrote: > Hi James, > > Thank you for picking it up. > > I tested the v2 patch series and it looks good. There was a minor > difference in 2/39 tested perf data files: the number of brstack samples > differs by one, however, there was no loss of binary profile. The resulting > BOLT profile converted from the perf script output was identical, so I'm OK > with v2 patch as-is. Sorry jumping in as brstack is mentioned. Now branch stack is maintained per-CPU wise, it mixes up branch stack cross threads. The patch 03 in the series [1] refactors branch stack per-thread by using common code. Hope this can benefit a bit the profiling data quality and in case you are interested in. Thanks, Leo [1] https://lore.kernel.org/linux-perf-users/20260526-b4-arm_cs_callchain_support_v1-v6-3-f9f49f53c9dd@arm.com/