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 34E34149018 for ; Sat, 17 Aug 2024 23:06:59 +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=1723936025; cv=none; b=P099i5SV8CqswK6XsNBwmukMyEMWMeTJXTIjh7MhexzspO2sp+XO4GzkRFOWlCEZkQxmelHcYgZdw+4j5c5hQJxadKGbUWQOzQv1+EYhIYUYSjarXe34rRdWeHeHCm1s3QeUwV63qWBeZN+WNVVWqcOLhp71ouaBtkKnD9s5kKA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723936025; c=relaxed/simple; bh=UuCaKBlTxePsFkys14JaLzrfdXnMXRAS1STarqX/H3w=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=LTCQzBkSQPElPHL5X5AX6HFBOTmZvPZfOrxM0RqaV7YdRYocwMs3lPRk209U/UMH42Vho/jRtO22/j6Rs39J63X3U5aIiNU6/wCvx1CYvWIodunlS+NslGDwpTqvtgcHlB0gBTXK5QulX29fHzOteiEyE675flaRYralGnSehB0= 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=eNpYZg2D; 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="eNpYZg2D" 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=nXyS2sUo1n0Mw1n5ITMhmlne7GDtRzGJn7gmD/Y/8P0=; b=eNpYZg2Dfk8WK7soZM3/ImEnOl lUHkXGZpJZV/h4A8dHxcxcxd5KnSza9q06TuRSplfLjYhtR8qi2Pj3LSz3L8TDKd2Ae7mnLApoN4b gL/OXJ/egK7je1mbGsMrjwxKatMMTB7gtlye8iPheaZV8h2H/kRhY456Mp9RLpjXWHlLBdJ7tfmlI SngrxIDGZuC3e35EXKpTV5iy+4B6++ATG86YBEApkgd2SBKrx0T42uXb/KRI/nObhsqoA24oZwERE eKcK890leicSiFBO4KR0q8opL5bo/tgRzx6c2MQQ/OMOCGrvPf5hfdOUYxl745YWt8IIVPKW9Erl7 zGdzQBFQ==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.97.1 #2 (Red Hat Linux)) id 1sfSVI-00000005AjH-3mnL; Sat, 17 Aug 2024 23:06:36 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 8798C300848; Sun, 18 Aug 2024 01:06:36 +0200 (CEST) Date: Sun, 18 Aug 2024 01:06:36 +0200 From: Peter Zijlstra To: Vincent Guittot Cc: Valentin Schneider , mingo@redhat.com, juri.lelli@redhat.com, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, linux-kernel@vger.kernel.org, kprateek.nayak@amd.com, wuyun.abel@bytedance.com, youssefesmat@chromium.org, tglx@linutronix.de, efault@gmx.de Subject: Re: [PATCH 19/24] sched/eevdf: Fixup PELT vs DELAYED_DEQUEUE Message-ID: <20240817230636.GB20319@noisy.programming.kicks-ass.net> References: <20240727102732.960974693@infradead.org> <20240727105030.514088302@infradead.org> <20240813221806.GB10328@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 Wed, Aug 14, 2024 at 02:59:00PM +0200, Vincent Guittot wrote: > > So the whole reason to keep then enqueued is so that they can continue > > to compete for vruntime, and vruntime is load based. So it would be very > > weird to remove them from load. > > We only use the weight to update vruntime, not the load. The load is > used to balance tasks between cpus and if we keep a "delayed" dequeued > task in the load, we will artificially inflate the load_avg on this rq So far load has been a direct sum of all weight. Additionally, we delay until a task gets picked again, migrating tasks to other CPUs will expedite this condition. Anyway, at the moment I don't have strong evidence either which way, and the above argument seem to suggest not changing things for now. We can always re-evaluate.