From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 033ADC43460 for ; Tue, 27 Apr 2021 05:57:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D5347613BD for ; Tue, 27 Apr 2021 05:57:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230128AbhD0F4V (ORCPT ); Tue, 27 Apr 2021 01:56:21 -0400 Received: from mout.gmx.net ([212.227.17.21]:60501 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229578AbhD0F4U (ORCPT ); Tue, 27 Apr 2021 01:56:20 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1619502876; bh=4SozHBhMS5Q8Rjl3HiUYSX1YMImtT3zCoY8k6axU3iM=; h=X-UI-Sender-Class:Subject:From:To:Cc:Date:In-Reply-To:References; b=ECNROBuCdUH/MSwQlGMNlObOQEafMHP7tGoJgY3Aho+Zsq9AzMnKz+NFLOeORGatx dCiZW1S6wpi9HYROFcgmI9UCx2XdWCjid+nuDe9XFotjQJBtvLIzU67nmWdPgkBC+c 6PvX7BCIFWu1/+udYDU43thxn2RTAWN/jMV/WrLk= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from homer.fritz.box ([185.191.217.83]) by mail.gmx.net (mrgmx105 [212.227.17.168]) with ESMTPSA (Nemesis) id 1MA7KU-1llgoL4AH4-00Ba33; Tue, 27 Apr 2021 07:54:36 +0200 Message-ID: <3fe7113cc87ac89077b55ca55bda2b99729f13c8.camel@gmx.de> Subject: Re: [PATCH] sched/fair: don't use waker's cpu if the waker of sync wake-up is interrupt From: Mike Galbraith To: "Song Bao Hua (Barry Song)" , "vincent.guittot@linaro.org" , "mingo@redhat.com" , "peterz@infradead.org" , "dietmar.eggemann@arm.com" , "rostedt@goodmis.org" , "bsegall@google.com" , "mgorman@suse.de" Cc: "valentin.schneider@arm.com" , "juri.lelli@redhat.com" , "bristot@redhat.com" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "xuwei (O)" , "Zengtao (B)" , "guodong.xu@linaro.org" , yangyicong , "Liguozhu (Kenneth)" , "linuxarm@openeuler.org" , wanghuiqiang , "xieyongjia (A)" Date: Tue, 27 Apr 2021 07:54:32 +0200 In-Reply-To: References: <20210427023758.4048-1-song.bao.hua@hisilicon.com> <9a6cadd9b65068b52c95adc44119bd09c6a4f9d7.camel@gmx.de> Content-Type: text/plain; charset="ISO-8859-15" User-Agent: Evolution 3.34.4 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:VGkbZIHqRz2YuSWjg2sJQ4r3WPhkq+LeT9fZwooJyCuvehLif6G cW0g4T5gMpqWhN1hw29A5ogOBhZkjUX2lo+VKpo48gD1AGoCbbQ7jhrf8qRWYMI8E8zWtz2 Oe2ia1DGrJsHL2VsC6dIAIZYkz3wLaZqCW5zzwzgBzvAd29GoKiPVIAxfspbUg+Fw2KPqNJ sDKVPgRI9RR7LK8U9t/Wg== X-UI-Out-Filterresults: notjunk:1;V03:K0:2/fobH0T9/c=:ii2hab9nNDI0n1MjFDiepJ 7gDuCQYhVP7+jc7rpTprjR8UXwtN5mlANMDN+7dIWli4Z6XapT91m32KpKxxt8G+DbKjgtbkw RBsIECTenGuwGuTZo1yJa4cn3r/J/3Pl7pW1oQ9N8IhS/IqK6M962kYTOLG5ViOmaUrVWjX3S FDKt+HREzVlqBtB6qgr+y66GNH9jogJWPiaxo3aBtAOhKWb7r9WvDzjU/81o5XUQ5RBKBjwZs aMcUV2FsdC9msYVJGhBk21iAlPjvpUVvUWgEewYq1JD1xIJvZKNlWWKD0U3+Bs3PNUONa/Mhh 5mbLIpIYxwwEEZjTQN6LJONaSTRCRQAnw7WPbnHsLkR+8JhAfMgyfxfLF4Tz45yYqrtQCdzA4 FCM7i/9flTk7IReaKnTIBkfCK+fAgoCPiRqLfw05IRobEClC3MNxlQ/A10dXGK8b+K73z78ch gUGemYJz5GGXRMgcRVdeRB/IKnGVQBmHzG8Ob1UZnCXSK8IiN07Lo3MvZiqlxzP1xytDMI9+c OSDlvY143giwKsTxKV+oppuqI5Vqgrt5Hbuqofw5bFvgSDbPhB9+Xgm9wrCifwTXrdWMBZQLv hvPRzWIImgx43gcVUE8a4nBeadL8z5pPQEkb1/IC9U3C2VFxj0zE6jO00Y5kv0Gb17g8xXfV/ YY2Sr5wxjw7lnUuXrF2JGDPMDyjw77qQ5f3pOHCUQVJz3dXXqxN/4bFpAseX4qv/CkFRENOha j/9acOz3tw3bGs98FJw5+aO7f04baD8aOnEpjLMsCdLp23c7rWuhloJvOsGyC1nFP45gink8O 09XRq+UTPYdRCnsa5VGG2TYZ24Zj1CQV/Acb03Ph+IbHVOzUTS2ZWhkbYcxhHgK8bkM6/bYsD byLqm0KNEq/LJOBAkM+amEW63exyVpS7YyHAxfKikN52KwkUuN8UUTY35p3BLKpjXKUYhwRH8 h/HAJhDduaZiIBRczw+pE+aqNvxMk9WtZnk3ImNbRVVcOZjWT/2tY2PbRwJE0ZTvTBqeOLVNm 6lmwCnidDVg0btuiPXiVxlTPRgeddCoL6LLeFPEKviY3E68AAEq6gTW2weL3J0DSNfx8WpH1B 0UBUe5aIiTCEVrkpSU02/VqfY5+k9HWiDw3fOD2GcEkvNtQNuLsX4KWd4O0NwC4a38MsSgQkv Q1C9HkZAGQaihsJy2OV91RKZAX+ODCFnvNAnEq1jnnp61xP3JyjTxlQdRvI/2/c57tAw0= Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2021-04-27 at 04:44 +0000, Song Bao Hua (Barry Song) wrote: > > > I agree sync hint might have been overused by other kernel subsystem. > But this patch will at least fix a case: sync waker is interrupt, > in this case, the existing task has nothing to do with waker and wakee, > so this case should be excluded from wake_affine_idle(). I long ago tried filtering interrupt wakeups, and met some surprises. Wakeup twiddling always managing to end up being a rob Peter to pay Paul operation despite our best efforts, here's hoping that your pile of stolen cycles is small enough to escape performance bot notice :) -Mike