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 CD7E71BEF98 for ; Mon, 9 Dec 2024 15:07:30 +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=1733756853; cv=none; b=ULps0rnPCZ+Rm1TAyj1xmHFGtPCBi5mbRu6CQEUh6pkOQLRFhqDOyDUKiWzcQvhRmpNf2qdi64xE/PaA9V3+IQ81g2fNagOq9klQv7+O8/EN3/L9lm89r8FNrJj4/CPTF7KS19rJIOj2YeiQE30Ns1mBuXP7J9nJ2wf975FujEY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733756853; c=relaxed/simple; bh=9f3vujbTXO8uOl84Tyqa8qCxvsA2+EMws4ktPgevJV4=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=iHYU03UVpB6hwOWa1rCj90zaC4u/vjF1RmW396oYeUu5AANL8pQuhig6dQ391kFVKuYV4yXgTrdVOYvvLGcY8DOJpir6DwyB9aqJFnpSMv+wPFjJoFV/ojbpsh8iUqiyuWri8dpDNDwbMpLV94g4ZhCQrDiw6SpUS9reh8p9v40= 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=GPDhfPXV; 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="GPDhfPXV" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmx.de; s=s31663417; t=1733756810; x=1734361610; i=efault@gmx.de; bh=3OrKUs/zb2+Sg602XGJwth7C4F6rxN0Awgtak4ba/io=; 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=GPDhfPXVxP9A/PbUq3NcqeD7NlnAvYWQs2wO/lPGTAoS+w8VsaIB2CmFaKmoCUEn cMRVz4IWuh9H8li57A8W0Xt8yuENjLVr/WQ0uyyt8iP78tpp3zpjD0dXjMhVY5dKy xfnITywQd3fBYOCIXZMc64kCUhpG9QM8Qr2ZdoyHWgYthLSLnlz+on2+dYq3NJf1Y UjFkGnF2iQmHHZ4YryMc0m326mL41mfFDAybv+zoaLkv/9NLvUkhueXCDoJG+/Pse f4IuVjnQUfdK+Ac7P0A6tgT+Ung6vNmaZkWo1Eb2CQFkY380JwkNC8b4xemIienBN lfYE2NJMXxLz7cWSzA== X-UI-Sender-Class: 724b4f7f-cbec-4199-ad4e-598c01a50d3a Received: from homer.fritz.box ([91.212.106.190]) by mail.gmx.net (mrgmx005 [212.227.17.190]) with ESMTPSA (Nemesis) id 1M9FjR-1tELpG3OFj-00AKuB; Mon, 09 Dec 2024 16:06:49 +0100 Message-ID: Subject: Re: [PATCH V2] sched/fair: Dequeue sched_delayed tasks when waking to a busy CPU From: Mike Galbraith To: Phil Auld Cc: Peter Zijlstra , 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, linux-kernel@vger.kernel.org, kprateek.nayak@amd.com, wuyun.abel@bytedance.com, youssefesmat@chromium.org, tglx@linutronix.de Date: Mon, 09 Dec 2024 16:06:48 +0100 In-Reply-To: <20241209131110.GC117639@pauld.westford.csb> References: <95ff75cacab4720bbbecd54e881bb94d97087b45.camel@gmx.de> <20241114112854.GA471026@pauld.westford.csb> <20241119113016.GB66918@pauld.westford.csb> <915eab00325f2bf608bcb2bd43665ccf663d4084.camel@gmx.de> <20241121115628.GB394828@pauld.westford.csb> <20241202162427.GB1226982@pauld.westford.csb> <9c78aebb3fdb8af68937a0301fabc3acb3e20c2d.camel@gmx.de> <20241202191252.GA1233297@pauld.westford.csb> <20241209131110.GC117639@pauld.westford.csb> 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:wAYYlXVoZw2TRPxE4rc/77KB9H1z/UUvpIf4jqdp5RtwUSAOEyT Nl12iTbZ4sxaj3y/uyyEGtAUXbJKVuEYtTvDaTB2Es26p5emXsvpUgH5p8FZm2YRrocyCQ3 DHSez03BkwZBe+our+nosYkbx3WTdEPNga5ac3TBrzCET9Cu8/D2NX5HfJlZ4Si1yztm/BW iq5jgvHdYSihT5UrK9pog== X-Spam-Flag: NO UI-OutboundReport: notjunk:1;M01:P0:C9ThPDmQbsw=;V/pbmfcMlUedIU/AgzYwjWO3yg7 l0A1ZWkWRHvbESkkoo4OevBscz8LoAuryF+HJPEmFw9ewUEg1na/o7r1/MMcVFDFTEzRZ2NLj Ch2sksPcML8xDXhduPRwNMgtV0c4mmYpy9nW5LjJs00ZAoppzbnT6t6D5AHYcizB3wqBT6NX6 edXVD36R3ehUMf+URrkHTdzjPM5fzvJWqlzzSnE+805N24e1CZEZVy1fxF1d0Likx2ynKBXa+ /+PC/LUU+4GmE1msC5ZYNIW7ZLdX3S6Os2rU/zPLI2I76UBCre66yJAYSavTx12K4kwjrpBwX 3JMgPezXf/YSofxh6A0MDW+cii/iW8Lwb+GTCrQcyT8XWy4Uv3ZO7UmHhkGanfoFmTFAcmy8c DMc0pqN8WbdqrhjSpuaXIfgU/A/WwvfHxv0Ozk8UsiixOiDiG0kkAKT2kLVB2I+LxAlxyH+wO lVDzuonX1dsQCyZ/rblNFv1SNqTiXvYsY9xR9L25pXuWwKNsMCmC4IH41/oc1zJ5cRGilR0pw Z4cIKy4Z1hM8SdysF50/mKSN2FE3NkxDJucgcDelyzEV2zHN3Xam4x3Ng7PrCHBB5AxvSA28s ieBvhnitU81dBKkDwIzfDBYAJcTcO6GLLk7RBl5+kCI7JBXsEzShlvhRUx6IFnBCOsXhqsWUu SWAfCJIN8oZ0lQwsXlBJWa5GrVjD0lj+OYIupjgC/iRbufaMzMLRMBYjq8zgoQHU2YcvJhE49 FJntS830sFLpD8QnkemUhD1p+OyJqmafJthE691EbwDTJe8KGqaFK34KoXwsxZ4WXUqi40Ede +1HBo/D2QuD/zDfDjWP8F6Q9fNPpOCMdlROPHtXqF6VKO4yQYYMg8U2cwV5CHm+hdRvlL1tSz o1V6lV2d7MgecVzcZ2i2Hucu+q7FG1KY8ICuEUOnRtlEb2bBcHc8a4pd7sYBJB58etYWbCbHO MdeHeZ0ZOqbgwr44JCPwy7XLR8OyYlvFJ6Qmv9OBPEXhumrHCvu+Gg5iehqxBJIV75O5H1tuN xLzUmVS0vKryIJblXmM8v8cbTo+a2Toho1mle0tCmd8cFh7sVNB2qAiAwX2Z1IPM7dhqO9GQm kzm17VwwoNpFuHXJoYB1D0zs32Fbnm On Mon, 2024-12-09 at 08:11 -0500, Phil Auld wrote: > > Hi Mike et al., > > On Mon, Dec 02, 2024 at 02:12:52PM -0500 Phil Auld wrote: > > On Mon, Dec 02, 2024 at 05:55:28PM +0100 Mike Galbraith wrote: > > > On Mon, 2024-12-02 at 11:24 -0500, Phil Auld wrote: > > > > On Sat, Nov 23, 2024 at 09:44:40AM +0100 Mike Galbraith wrote: > > > > > > > > > > > > > Question: did wiping off the evil leave any meaningful goodness = behind? > > > > > > > > Is that for this patch? > > > > > > Yeah.=C2=A0 Trying it on my box with your write command line didn't = improve > > > the confidence level either.=C2=A0 My box has one CPU handling IRQs = and > > > waking pinned workers to service 8 fio instances.=C2=A0 Patch was us= eless > > > for that. > > > > > > > I'll give it a try. Our "box" is multiple different boxes but the resu= lts > > vary somewhat.=C2=A0 The one I sent info about earlier in this thread = is just > > one of the more egregious and is the one the perf team lent me for a w= hile. > > > > In our testing this has the same effect as the original dequeue-when-del= ayed > fix.=C2=A0 It solves the randwrite issue and introduces the ~10-15% rand= read > regression. > > Seems to be a real trade-off here. The same guys who benefit from spread= ing > in one case benefit from staying put in the other... Does as much harm as it does good isn't the mark of a keeper. Oh well. -Mike