From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 3D199143725 for ; Thu, 28 Nov 2024 10:15:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732788956; cv=none; b=cBx2OX+kNbsyoNBcUUzjFuYZszBA/LEc1XByzSPHfEpefcXeO9fiYgqw++Fb9ZLEOOMv//mGW8l9u1y+ruEYc0RndidbwsXvVOKF9DazxQHVaYR1qxeGIuRlzzzuRxG75DPWQvEb3TMPLM3bhY6s/rsOSK57mJNjRIsv0adWHKo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732788956; c=relaxed/simple; bh=7Nr9UIEVV+XzhExgqwiEzpB0WV8vLl7DC6JdbT+ioQI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ffpDEQ8kOTeWwVM6XQyCXO2aqrl2MgLzbi5tjvUWkUnVkmzTGlRtfIBd33XL75Jr2LlBSfaVzGG+t+yjmN0lraVsitFqksJR2+0nRjpfmdP7GWRrfsBIIk30UPIBpbYSnNDGgzYyn5zZ5MBPY4dSATT1NkBrCgkq9iNShBTSExw= 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=WbnLov5L; arc=none smtp.client-ip=90.155.92.199 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="WbnLov5L" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; 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=0vZ9oVjB8dTpIZcQ2036EY8cTa44ff4rYb+HADHRyoc=; b=WbnLov5L5u90s0DgFd8lUCYbZw rHFjN4s9fM3u6OE1BjqUcTq/8iyt85bPpCGmtC4uwbQDGQz/mTOtvYzgBWo4cmif44VOd/990B246 jUYLlnA1+ASN+EXGcYPJSq07V+Be+3l/O4WMuAkLiBZrDOt4AxVAmSYJkWDq59Nf+DKirkGJy48di BrGo3NKWydOsOQltYupfiKb+L7iwNQmDKzsSGoCJ2SLn5zy3SLSc+fZar14tJOrrNq7T6jjenZxHo S5NStmGyuqo5Bvtgwi1lnsYIWf/cIGOZCYZNsTHChZw4bf7T4jmWIqLwEOK3tkFzOa6gMfkvDQOMA 5jBbxnaw==; Received: from 77-249-17-89.cable.dynamic.v4.ziggo.nl ([77.249.17.89] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.98 #2 (Red Hat Linux)) id 1tGbYr-00000001aNs-3tk5; Thu, 28 Nov 2024 10:15:50 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 8882E300271; Thu, 28 Nov 2024 11:15:49 +0100 (CET) Date: Thu, 28 Nov 2024 11:15:49 +0100 From: Peter Zijlstra To: Vincent Guittot Cc: mingo@redhat.com, juri.lelli@redhat.com, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, linux-kernel@vger.kernel.org, kprateek.nayak@amd.com, pauld@redhat.com, efault@gmx.de, luis.machado@arm.com Subject: Re: [PATCH 7/9] sched/fair: Do not try to migrate delayed dequeue task Message-ID: <20241128101549.GD24400@noisy.programming.kicks-ass.net> References: <20241128092750.2541735-1-vincent.guittot@linaro.org> <20241128092750.2541735-8-vincent.guittot@linaro.org> <20241128094936.GA24400@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, Nov 28, 2024 at 11:03:44AM +0100, Vincent Guittot wrote: > On Thu, 28 Nov 2024 at 10:49, Peter Zijlstra wrote: > > > > On Thu, Nov 28, 2024 at 10:27:48AM +0100, Vincent Guittot wrote: > > > Migrating a delayed dequeued task doesn't help in balancing the number > > > of runnable tasks in the system. > > > > But it can help balance the weight; furthermore, by moving them to a > > lighter queue, they'll get picked sooner and disappear sooner. > > When groups are not overloaded, we don't compare load but only running > tasks t balance them across cpus > > It's only when both src and dst groups are overloaded that we look at > the load and the weight > > > > > Perhaps make it: p->se.sched_delayed && !env->sd->nr_balance_failed ? > > So we could take into account which type of migration with > env->migration_type == migrate_load Yeah that makes sense.