From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mout.gmx.net (mout.gmx.net [212.227.15.18]) (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 839093BBEA for ; Wed, 3 Jul 2024 13:45:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=212.227.15.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720014342; cv=none; b=V5lg8nFq0Jr7i4l6+ExVBQ73JJ5fft6km8aM5qu9zPx4OQtSAA98P8wFldDRrFMUDSzqTsCe6bhswbi/eq5RJ0KKg78HeWh72qiV1SBZrhHHDxEXJZKIq4PEZp1YRozI7X6sNIAIIyen1bM3l1zjjHLNvECN7Ac//0A1hKdlnkA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720014342; c=relaxed/simple; bh=8tA7B8QLastRGbA7MeBQsihKnyFlqwm/jcWdR5LFPYI=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=bIJu03AcqpWCKk6ii3VfcrzpgtkgijX9mNxKXMie87lr48/hYUG1tyxHQeLiKiQXpjyswYS+pW6V2U4cm6+1sD12ogROhomhuhKNvO02nEmW3BfWj5yuj4TliHI35GGfj13WfpzODHA94IRHQQoIxoH07BF4GuBJX1ASuMlLC2k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=gmx.de; spf=pass smtp.mailfrom=gmx.de; dkim=pass (2048-bit key) header.d=gmx.de header.i=efault@gmx.de header.b=Y0wOjUJy; arc=none smtp.client-ip=212.227.15.18 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=gmx.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmx.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmx.de header.i=efault@gmx.de header.b="Y0wOjUJy" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmx.de; s=s31663417; t=1720014316; x=1720619116; i=efault@gmx.de; bh=xu/SnLB/Fljhm4ChiQGySOZFvBpo/HmJl/ceRfBF5lk=; h=X-UI-Sender-Class:Message-ID:Subject:From:To:Cc:Date:In-Reply-To: References:Content-Type:MIME-Version:Content-Transfer-Encoding:cc: content-transfer-encoding:content-type:date:from:message-id: mime-version:reply-to:subject:to; b=Y0wOjUJyezvuvNnBR0hM1drkrs0snD/2cclcc3n05TT4naD4WwZKo8BQfzv17xbO 5V4KsGhK9PGWgJJrpcn8or3bgd+od/xWoIg930Zhio3vWcQhf7Jp2rSo6kWlfqgcn jmWoEV1gxj6jn/7s8kU53BQU//j22dpDl30NbVJxxP3N8QMSYI9f1U/SZ7VX5tqhg 8p+EFl4kA85OQNCLZd3YXRWJg86GSxDorCxLCQ2SrYkSUt+U2nrlQ9Hs46IZ+wosC RH8CZMRKTaGiWZrO1pnxCHAR7RupCb67IYeYPl+79xH/Ki3Ik4csSxyPDxMzReiY/ RrKGsk6sNFy9HNweQA== X-UI-Sender-Class: 724b4f7f-cbec-4199-ad4e-598c01a50d3a Received: from homer.fritz.box ([185.146.49.228]) by mail.gmx.net (mrgmx005 [212.227.17.190]) with ESMTPSA (Nemesis) id 1MGhyS-1sclw60mA6-002DUJ; Wed, 03 Jul 2024 15:45:16 +0200 Message-ID: Subject: Re: [PATCH 1/2] sched/fair: Record the average duration of a task From: Mike Galbraith To: Chen Yu Cc: Raghavendra K T , Peter Zijlstra , Ingo Molnar , Juri Lelli , Vincent Guittot , Tim Chen , Yujie Liu , K Prateek Nayak , "Gautham R . Shenoy" , Chen Yu , linux-kernel@vger.kernel.org Date: Wed, 03 Jul 2024 15:45:13 +0200 In-Reply-To: References: <338ec61022d4b5242e4af6d156beac53f20eacf2.1719295669.git.yu.c.chen@intel.com> <683663e3-cef0-bb45-e1c7-5bf1cf44209c@amd.com> <4e28fd17d7a2f7146aae10a76982f0e58b22befb.camel@gmx.de> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.42.4 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:p0uamndQAjL4e7FwOMZ7TOF2MxJK5kuYW1n/tXa8UjF/5cQDwl2 qzNnzVhqd9PVCrut7fyYO6wWYKXGH71WlQ78nqfVG7wKiJIfD0C728id3rUMiSH0ohCzvGL iasFd84AUFp/N6wsYhp5HfKhB1CTmnyJ5BIOK8N0Jg5l9bERhuUEMcGNxd6pv+mHkA+hkzM kpgHfVCLTNa1kEVSTnF3Q== X-Spam-Flag: NO UI-OutboundReport: notjunk:1;M01:P0:2ddTCT/aiA0=;sq2II4r3/R26cAeM+jAJ97f8R2P ht1lviK94sWWv5dqh7POUNaWnS+Mc68qysCsn66x+06W2Te5RaoNDuE5XPsYZwXuLoWUGe6HZ BIdkge1N6iJlHuWUyK90j3cyxWl+FE5UsLkBaUkbfYcu/EuTN/7+/rrPZ9hSEp4IbjTaEU6ZK pO4PM887XKN4TghsZNYLVbMwiq3oUbkI/OVK3L2avB4W1CrTHyGui4h8U2rP7zJGmVvqdSj6U GVG1DBENHCb+QanxH/203YqdtL1ldwWduTjD/39KGEpZJtBfIK0AOiGNA9LkZ2q3RMpgxJw25 K8tGT6GWGDqJESCpVaaPYBMgAsYymBW/yWGLdoU+/xRrwa8Y0OOXB1OJ2EJ9L3FNbbWFOZZkX TmY6N3bDR2hqxq9yPNM50nGfTUp0URPd5jBoJlt1YrEbo2GJZsWRX4aTM6cdiJ7b0vRpEF6jK WrVfJDw4wRVy80Qjwh61L4oR6aWnoSAM3BllumiJh03eu22OPCPfiKLsYm3eNE29M81U0Ie25 5aFd/iN5xHdU0jdSDiDBQQWpyi9mxMewju8tA9TshFpv1ohtb5zNqLQUYbgmO1q1/TPzGs/05 2HQosVumamzztNsJfiHZNJED7ga12TW0slwOh94jKgDm82ucmjLweg+YjGzd+U7J4CJoynx/i tYvcaujkwNTD968fhI+U0ujNUVgk5EblD7TOWnEXNvvl+Q4uM5JeSkSlrkP4RktoxvE6r/JWn Kc1BQbJMDDcTHyaaXbuel5n8N18VD3nZZ9a0VDpycEsHxbiq/bZXoGuaLDUsKtFEjp0A6K0J6 YGr1ZuohATV2ggaq+4LwXSfgCdJg/KHbZJ4DUOehH0+EY= On Wed, 2024-07-03 at 21:23 +0800, Chen Yu wrote: > On 2024-07-03 at 13:57:19 +0200, Mike Galbraith wrote: > > > > Oooh dear.. as soon as you mention threads, the question of who's > > wheelhouse is this in springs to mind, ie should the kernel be > > overriding userspace by targeting bits of threaded programs for forced > > serialization? > > Do you mean the threads within the same process should run in parallel > as much as possible, regardless of sharing the same data, because the th= read > is designed to do so? If so then we should probably skip the 1:1 task st= acking > if the waker and the wakee are in the same process. That's seems like the obviously correct answer.. except for that leaving virtually the entire issue you're squabbling with lying on the floor. Grr, how annoying. -Mike