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 8E2C7168A8 for ; Sat, 25 May 2024 06:42:06 +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=1716619329; cv=none; b=VMwr3CvE2aYSgz1TnKEuTJ2YQpvRYdxMImx5w7rIu11clwnv/uBqfoXgL/YcGDn4e4vOAbplQNQGJWTfUSk2hAjZG6OEC9rR1U+IqQf5m+5R+jUV6ZQb+Z8dp2yRn9tuJQ53QDi0ar/JxjY/nLre7r72WXk5WQu1bIZRPgk/KmI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716619329; c=relaxed/simple; bh=NVYTG1KelWlZ3U/zjHd+3dkdgqx8s3SXiVjfpb+XxP0=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=vGueQaxcOk8Ha4w5+kNXPjjPT/qOwXCju4PYhka+C5hDms0QEoXXDjJgUWh5Np/pFXS6tB9D9zyTcL4xFg7nLD/tqiVNZiPwBhOP7V1UOvzcCoUAB6Tex43JU3soK6ephp/oNsQNAdIKjLrYwn5Vg4g6JTAjObkexm7WYvZ/RMA= 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=sZnIxoFc; 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="sZnIxoFc" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmx.de; s=s31663417; t=1716619290; x=1717224090; i=efault@gmx.de; bh=ErbBimvCy1bCr6p/ayJoAb+oHSOlcaNDbpSKcAN0Ptc=; 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=sZnIxoFcDh7uA5NYOHec93mg7BZSNIyMhqJ6GwQhyyzv7iL3HTF0b5uZX55Vkh8T sU5n9WuON0q3jg8bx8rrUKpkowbX4o0tLEYjapHDe0x7MnmTMoV67bzscK06TnGad wcFUa/joYs+EtgSUyOJ5YsR8x7ox8OMyVMjO+n252c8KGMUsboTF1EIbOqZjVLHoA pXPkroT40V/jcZHToTyWhF2egdLNcSOs5DRV4GGBLU2DjMOBCSpXvrm1s8x2YJ+u3 w6YBTqgEIF6Dj9Em6rZG4oI/MlCUKlb7Gw1+ukey0+zXrG7s302FWCfuWzU1SZA6r WykHFYrmrgRxDWCjWw== X-UI-Sender-Class: 724b4f7f-cbec-4199-ad4e-598c01a50d3a Received: from homer.fritz.box ([185.191.218.78]) by mail.gmx.net (mrgmx004 [212.227.17.190]) with ESMTPSA (Nemesis) id 1MQ5rO-1roqWP3v6G-00PJ1R; Sat, 25 May 2024 08:41:30 +0200 Message-ID: Subject: Re: [PATCH] sched/fair: Reschedule the cfs_rq when current is ineligible From: Mike Galbraith To: Chunxin Zang , mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org Cc: dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, linux-kernel@vger.kernel.org, yu.c.chen@intel.com, yangchen11@lixiang.com, zhouchunhua@lixiang.com, zangchunxin@lixiang.com Date: Sat, 25 May 2024 08:41:28 +0200 In-Reply-To: <20240524134011.270861-1-spring.cxz@gmail.com> References: <20240524134011.270861-1-spring.cxz@gmail.com> 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:F8+ucXL8zD15xrGySnVifZdwv9cUEwVOKZrCFHTKqDuWDSl5m5Z I5MmD1wlyZvpxZam7ZszIexTqlv5u24xfJZJjwhGyKpG8472LsIojMzAKUvqk37UUJeAzU6 U4mc8CiSYzj57rmHpNucpyoTi7IoU7tQqAy+cn07YqKP+pRXdmbaGzMZxYwLlx+aE6MCQOF jVlkbCgGu2KXAASsABNmA== X-Spam-Flag: NO UI-OutboundReport: notjunk:1;M01:P0:U9fMDJrsvB8=;KCf9KHGJOT/v7EVej5/fMdOOwFJ 2C21HoYSrOFG+M1fxcRYZhMI3gy/VsWUwAYdXaUzE2z9kmEA1NHGD8Cq65+Ty1TSyanzTaeuy 9yY+0X1seomsF9FetK5PQ6H6P34eajGbnBE0gp2BzKYg5L+RahUrJ5kr++LXXT1KRV2vNvjsS VX9hjD1kd8ZbPnIlqw2cVuP13f2IFgRGUNRDFUYy11UQAFkf7VtMuIuuU+2OQApN+i+yO61El IE6NStuhQLfgeViO9nI7xKCggZcqT20WgD7h23fu+MF/oKw7xgA1ckFvamRTg6M4NmnninO2N o3PtYa/vE2pa0HbAdFSOaPoIRokNlrGt/PMGfFWB8JROcIzllYJbzlgPI6U8dmK+S+lqkBRXT RQEs+w5ltAywssNi0S/yhui+nSRxl97gh1iD3evG8g6ytJkVFwGsvH9rURjY02vbqlsLZ04E7 NLkWjS/CDGgrojMQRjsV5ZcCGaJdLINZzXqJ6iP5ADipf8wfz+g1rAa4aoRSTS2P6yHJHTaA7 LVnIRC/MO9bsokEPQQghM3gd0bNqbu2CATP0rl4IwHlsFMgcC8wSCDOYHbRjww6rYuVtN+ZQF Q6MnSiAEig0Y0rRPLmHoIXxp5ByZwtmm+CFtoMj002OA3Z23PNOSnHUxS0rJ+/X1tEQcxmUzI XpBaJ7ioUeWRqsZqjaGa15I7gblDt8MXAUR84U9snGUjqgID98pk467n0bx1NYwyVrXwXtNxH t4eccqcMjg2KNlnWbWJ57Y1Ac51xkZ8YAblTnVZYcRkxbqMkJiwsGwWqKT42R/iOClO0tAHt2 VciOoOoqbgHjEADXoPrTtpHDYMHjwFWv5XIV0ky5UCSOo= On Fri, 2024-05-24 at 21:40 +0800, Chunxin Zang wrote: > I found that some tasks have been running for a long enough time and > have become illegal, but they are still not releasing the CPU. This > will increase the scheduling delay of other processes. Therefore, I > tried checking the current process in wakeup_preempt and entity_tick, > and if it is illegal, reschedule that cfs queue. My box gave making the XXX below reality a two thumbs up when fiddling with the original unfettered and a bit harsh RUN_TO_PARITY. diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 8a5b1ae0aa55..922834f172b0 100644 =2D-- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -8413,12 +8413,13 @@ static void check_preempt_wakeup_fair(struct rq *r= q, struct task_struct *p, int update_curr(cfs_rq); /* - * XXX pick_eevdf(cfs_rq) !=3D se ? + * Run @curr until it is no longer our best option. Basing the preempt + * decision on @curr reselection puts any previous decisions back on the + * table in context "now", including granularity preservation decisions + * by RUN_TO_PARITY. */ - if (pick_eevdf(cfs_rq) =3D=3D pse) - goto preempt; - - return; + if (pick_eevdf(cfs_rq) =3D=3D se) + return; preempt: resched_curr(rq);