From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 08D51264A92; Wed, 21 May 2025 12:05:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747829149; cv=none; b=dgALn+/PrmZCKoaiCS52vynaK4rkBlbpF7GzGCctudmF9l5lbvfIHvkk27qVKEHQFVlOi3Q7hqPxoc+CmS1+jv+jvb3IO7QxRqW/RdKie3QHpRM1nyJGADr882W+cWV5G7PEkzArKBoWmQRnZzXWbR/kI5HpY15zecRH1+E71AM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747829149; c=relaxed/simple; bh=6y6pA2v91iQmSvQgFz0Uojt+/84qWji3dUd8c5vCkkw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=idWlK6KTJb2doRgBcLHm1vuWcwbS/Kdz/L7OSz1lNemOuIF0dFLmD/+S619MRE9oObfefI7GgpmX+gp5wJ9P9O6Pyhh70jQn/Lm4QgBqdedZhDP3szK/oGvTIMRw1voM7ogkcNnXtUkFONshEmBKOXIQ2DCK1h3I0c1+cqfDzyw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=pxlgghmO; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="pxlgghmO" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=fiwT5IEBfiiewAOT9kPl+ck8nR9/bB1A4OgJlEVgr4w=; b=pxlgghmOtwAjfkB5+OFBi+X16q CIldROuYOtG65qBi/T1OmF9JzmMDUj2tRHenO4jH/OrGMrOwx3bvfvmOOdPMqvBBVwx8sr+sG89Pp Gh2EdoAIxGHbXQV3dskV5JrwErhXiClfC051cA+F141HG83ExLpCY3hU+oL4qXp1AeH70u8DfhHWk mEruWH94WUvG286y74YuXmn1bRX/MPngMEWGqPXBRt9c/F0HRPJ868HdiOPmDEkSxDeJql2Z1wJUB AVxOSYRFHcQUT30ZVYrcT1AZE3ASlpFE0IFx7hGe6Cm8yDbNzqKyl94cF8BC5qB37jrCZoYQbfUwL wNEdK4Jg==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1uHiCc-00000004ctY-0qD5; Wed, 21 May 2025 12:05:42 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id A0548300583; Wed, 21 May 2025 14:05:41 +0200 (CEST) Date: Wed, 21 May 2025 14:05:41 +0200 From: Peter Zijlstra To: kan.liang@linux.intel.com Cc: mingo@redhat.com, namhyung@kernel.org, irogers@google.com, mark.rutland@arm.com, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, eranian@google.com, ctshao@google.com, tmricht@linux.ibm.com, leo.yan@arm.com Subject: Re: [PATCH V4 02/16] perf: Only dump the throttle log for the leader Message-ID: <20250521120541.GD39944@noisy.programming.kicks-ass.net> References: <20250520181644.2673067-1-kan.liang@linux.intel.com> <20250520181644.2673067-3-kan.liang@linux.intel.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: <20250520181644.2673067-3-kan.liang@linux.intel.com> On Tue, May 20, 2025 at 11:16:30AM -0700, kan.liang@linux.intel.com wrote: > From: Kan Liang > > The PERF_RECORD_THROTTLE records are dumped for all throttled events. > It's not necessary for group events, which are throttled altogether. > > Optimize it by only dump the throttle log for the leader. > > The sample right after the THROTTLE record must be generated by the > actual target event. It is good enough for the perf tool to locate the > actual target event. So while both patches change behaviour; the first patch should preserve all that was done and simply do more. OTOH this patch explicitly changes behaviour in that what was done, is now no longer done. Are we very sure there isn't a tool that expect per event throttle messages? I'll take the patches, but I'm somewhat suspect of this one.