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 7B31D18E75A for ; Sat, 15 Mar 2025 07:22:47 +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=1742023369; cv=none; b=sQmF+N4zSPjmJ4ScR4vpTO792MPwmxNJViPLbF5CxrRxex2jlRoMNfYF2S1YbOHmAYuB6eJbeGTPCh91n/s3fmyEUjXLnA+nf1SP8i/CHeUIWO4pDP4UAgMyM5qRZuivG5W2kZBAdRL2b3X9rYECoHBY2guFwZkwKE1DGNw0/9g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742023369; c=relaxed/simple; bh=dLbiAJdVJz7bbsQu8yFXRQdfHcFo7iNvcSgGQRyrsTE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=f8q1/wEgUx0tO6ZfFbUQbFB8LHkc4iAGVcF7bDW0p/fqsXOReY/156JisuOCgJ7HBJUU8zkAah0i9IKpovLvtQuUa42NS1E5gLS2k5ermwtd38MYbh6k6W+05muylUQ58AfXyGJgE2t3l5EpscFCYG5BOyeyjOhHZoPJQpeaIA0= 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=hnplweJ7; 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="hnplweJ7" 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=dLbiAJdVJz7bbsQu8yFXRQdfHcFo7iNvcSgGQRyrsTE=; b=hnplweJ7b383i4UCAji1NyMuEJ q2Yb2RTVJ5+7G21QxvhGVF2QySb9uxp2UkPTerWc0Wd0JsL/42X08rRfQHNS934klb3NHSsYFxoLn eo5UbQh/GhempOU8nUW8ec/ZUsqib1qNjgztkp1eOF+/YS+IgcR+wJQrWV3+GL2s7AhVgVeqikCYl 8Ir+5z4n2eZ1wBOw2IHOjQo46uHCZxC4UU7RS6ouuiJxHA9tcXvYJq7/lxw4ttE6txjiTbYWxFB5z ThE99f4x3hAwi2QK73fyoR3+GLuN2pt5jhkOd9qDORqiBxhBORYCvyRAXkxTM78OamqfObxAHAnLv /ajjv8Vg==; 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 (Red Hat Linux)) id 1ttLqk-0000000Dire-3Blq; Sat, 15 Mar 2025 07:22:28 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id CE69E300599; Sat, 15 Mar 2025 08:22:25 +0100 (CET) Date: Sat, 15 Mar 2025 08:22:25 +0100 From: Peter Zijlstra To: Joel Fernandes Cc: linux-kernel@vger.kernel.org, Andrea Righi , Tejun Heo , Ingo Molnar , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , David Vernet , Changwoo Min , Luigi De Matteis , paulmck@kernel.org, boqun.feng@gmail.com Subject: Re: [PATCH RFC 3/8] sched/ext: Add a DL server for sched_ext tasks Message-ID: <20250315072225.GG36322@noisy.programming.kicks-ass.net> References: <20250315022158.2354454-1-joelagnelf@nvidia.com> <20250315022158.2354454-4-joelagnelf@nvidia.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: <20250315022158.2354454-4-joelagnelf@nvidia.com> On Fri, Mar 14, 2025 at 10:21:50PM -0400, Joel Fernandes wrote: > sched_ext currently suffers starvation due to RT. The same workload when > converted to EXT can get zero runtime if RT is 100% running, causing EXT > processes to stall. Fix it by adding a DL server for EXT. This needs a lot more words on why you need a second server. Because I don't think you do.