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 4670C2185BC for ; Fri, 30 May 2025 09:00:41 +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=1748595643; cv=none; b=SP9/Lk85bCYhBJTaDrBCetx6qSIAGboyouoLPGuEXM2jEdVuaBqlcyf3JjAlLEGPdMoZdTWElsffIrz4smVMisurMQ9guh6nSSMY33a3VfbXVxQm4Z4LviGbQ1WeyzYq5VKIZRH2J451JtDAAEGF+QDkeSlVRMA/Pazye2sy3FA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748595643; c=relaxed/simple; bh=LKTjIRMzHXn5Zw0J4fAUckDi/Sev3/I4ZHV38WVIG/c=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=TGgzH7m1SJvmo1v9dNzC7vdkj4WC9O571wvYOXNBlbyZ/7t3xT0Nbn0uJSt8LpMO/FXy2+vdiY7xQb4C9nR/W/XBWkJb5kWDpX/B0x/cNkRHPx2RSsY58zp23BYzk1Llv0a9fCR+T+wEQX19uWWUWzfvxCwwr2VJ2BrLMkT34zM= 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=XK76938Q; 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="XK76938Q" 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=0gdKVbBS+SWFxzq/DgDZxsQ+C2It/mTqNQOkQQfp0rU=; b=XK76938Qy1bxmx/KD2zaULIKYA JQFsKd1ixMvCZmmlkLRrg9AuLtaXiUf7ZvUXEUh/OWVK/w2mVLlB8zVGXVEZM7oQZOf38aGaLH2ct gXQF1yUPlUsACOCt9fm+yJHO89BUUBKIVmRDojHAAFbca0PqYXgbJ31UHAM+mBfYlAeWAAg6vFSKL iuNszF1JVaHQaPL6j6VmxTzV8lVA0cIZLD88XNWQKXbUkNHItV0tUT7aNbudJzA4f/AUX549GL3WD 2BidplAvMNYPSe/RYgurNvz4l2t0Dd3VSIaHtWFXYn5IPUx6CxC22xmyTEQzRI401vL38Apyc9Vb8 g1PCPpag==; 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 1uKvbN-0000000Fe0o-2NHi; Fri, 30 May 2025 09:00:33 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id CA9C030066A; Fri, 30 May 2025 11:00:32 +0200 (CEST) Date: Fri, 30 May 2025 11:00:32 +0200 From: Peter Zijlstra To: Beata Michalska Cc: mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, clm@meta.com, linux-kernel@vger.kernel.org Subject: Re: [RFC][PATCH 0/5] sched: Try and address some recent-ish regressions Message-ID: <20250530090032.GA21197@noisy.programming.kicks-ass.net> References: <20250520094538.086709102@infradead.org> <20250528195944.GB19261@noisy.programming.kicks-ass.net> 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: On Thu, May 29, 2025 at 12:18:54PM +0200, Beata Michalska wrote: > On Wed, May 28, 2025 at 09:59:44PM +0200, Peter Zijlstra wrote: > > On Tue, May 20, 2025 at 11:45:38AM +0200, Peter Zijlstra wrote: > > > > > Anyway, the patches are stable (finally!, I hope, knock on wood) but in a > > > somewhat rough state. At the very least the last patch is missing ttwu_stat(), > > > still need to figure out how to account it ;-) > > > > > > Chris, I'm hoping your machine will agree with these numbers; it hasn't been > > > straight sailing in that regard. > > > > Anybody? -- If no comments I'll just stick them in sched/core or so. > > > Hi Peter, > > I've tried out your series on top of 6.15 on an Ampere Altra Mt Jade > dual-socket (160-core) system, which enables SCHED_CLUSTER (2-core MC domains). Ah, that's a radically different system than what we set out with. Good to get some feedback on that indeed. > Sharing preliminary test results of 50 runs per setup as, so far, the data > show quite a bit of run-to-run variability - not sure how useful those will be. Yeah, I had some of that on the Skylake system, I had to disable turbo for the numbers to become stable enough to say anything much. > At this point without any deep dive, which is probably needed and hopefully > will come later on. > > > Results for average rps (60s) sorted based on P90 > > CFG | min | max | stdev | 90th > ----+------------+------------+------------+----------- > 1 | 704577.50 | 942665.67 | 46439.49 | 891272.09 > 2 | 647163.57 | 815392.65 | 35559.98 | 783884.00 > 3 | 658665.75 | 859520.32 | 50257.35 | 832174.80 > 4 | 656313.48 | 877223.85 | 47871.43 | 837693.28 > 5 | 630419.62 | 842170.47 | 47267.52 | 815911.81 > > Legend: > #1 : kernel 6.9 > #2 : kernel 6.15 > #3 : kernel 6.15 patched def (TTWU_QUEUE_ON_CPU + NO_TTWU_QUEUE_DEFAULT) > #4 : kernel 6.15 patched + TTWU_QUEUE_ON_CPU + TTWU_QUEUE_DEFAULT > #5 : kernel 6.15 patched + NO_TTWU_QUEUE_ON_CPU + NO_TTWU_QUEUE_DEFAULT Right, minor improvement. At least its not making it worse :-) The new toy is TTWU_QUEUE_DELAYED, and yeah, I did notice that disabling TTWU_QUEUE_ON_CPU was a bad idea.