From nobody Fri Nov 29 14:30:53 2024 Received: from mout.gmx.net (mout.gmx.net [212.227.17.22]) (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 8981B17C224 for ; Thu, 19 Sep 2024 06:10:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=212.227.17.22 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726726213; cv=none; b=jGa+1HeuGhqkNlP/BKS7m6Cscm2RT99dfJqX+0X4hSpy0ZiJoXgVaDpNmXYjHrDiXkOR/gOh047kq54sV7IQm3DHR5Q1/r2tHnGpXQeiBa8Yxz7jHY6IpR8nZW2BO4ealFKavxM5rHESxQ/DFLlojjNSe238RyQgRihF/fL27bA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726726213; c=relaxed/simple; bh=BO1wYNJnaESUGIUwV/ECvxyO2g6zYEmyq5UCy8kYrgM=; h=Message-ID:Subject:From:To:Date:In-Reply-To:References: Content-Type:MIME-Version; b=piMspogeOF6OEX6nkLMKqELp4EEWYM7r7nzbsxPQWlQXsdDNktXgo1KIZYqjL3VYk6fLC8u/LbgCI4+A2D9UtAXXxn2q1tDO0au8u3GYHGeMZ/GZYH71L+GMimMofQP2luBkPGp3rHFALCjYgnjVkPfC3pt1/fdGx01lF7vk8h4= 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=aCFxzc/o; arc=none smtp.client-ip=212.227.17.22 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="aCFxzc/o" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmx.de; s=s31663417; t=1726726189; x=1727330989; i=efault@gmx.de; bh=LJb5IgePZ4BgrdGP9a6NUaWhuwLLTGAN/jzME6Q2d6A=; h=X-UI-Sender-Class:Message-ID:Subject:From:To: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=aCFxzc/onYj6Q2SQ+7HbDo+qWKWNtDBRKEc16wA3v3YMUfnFjfDhdmbvQty+yV79 VE0Ukzbi9HUrt9Tm6FATyKLj8yif/6+nnorvEmqUqA6MSK4PfzIkxxVMyUcuNdZ9w It4vlHnbfYhPEUfWmuOGuZk5x71e9vyBEYJcBJf98d/K22+EZHc6PKUpdeKEXxOM6 u3tfsVppI4EAS5jFx7GCZv1vm7uT1xrblLQir0QXiYUez0ldRU0lNy1HAG6qCfXGf 6o/GNdI4uy5buvi3F5J9TQGBTCBbvsg4q94quFsB8Vw8ku3VpdfU2sXuNd/Tjbw/l KO9CiX6IlUfLgr5r1g== X-UI-Sender-Class: 724b4f7f-cbec-4199-ad4e-598c01a50d3a Received: from homer.fritz.box ([91.212.106.56]) by mail.gmx.net (mrgmx105 [212.227.17.168]) with ESMTPSA (Nemesis) id 1MCKFu-1shqxC3d6g-004GNr; Thu, 19 Sep 2024 08:09:48 +0200 Message-ID: <2fb24ab402d9de45e3cf16e6ba0ad23a7843e5c1.camel@gmx.de> Subject: [patch] Re: [PowerPC][Linux-next][6.11.0-rc4-next-20240820] OOPs while running LTP FS Stress From: Mike Galbraith To: Venkat Rao Bagalkote , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, peterz@infradead.org, vschneid@redhat.com, mingo@kernel.org, sfr@canb.auug.org.au Date: Thu, 19 Sep 2024 08:09:47 +0200 In-Reply-To: <82b9c434-a0fd-4488-95be-a45b8cd4b6e6@linux.vnet.ibm.com> References: <82b9c434-a0fd-4488-95be-a45b8cd4b6e6@linux.vnet.ibm.com> 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:zXiz7bdk1O2092M+28wKsKOHNyhGwevFOgeHjWiyixY3kKbkF80 q7f3jlBj+9u7JO6xwYWvhE7kaUeZxkf8JlcgwnNgFDoO9UY11S1Edb+4jGnS1KE+wgd0wB6 pPLUV/aRLuksGSrm1dAQX7VWS8gyHsmugR3ml5/qrSO0psnhlsrz7gOvpw5fB7y+S92AZ8+ jBnk5qcFCvDawigeur35w== X-Spam-Flag: NO UI-OutboundReport: notjunk:1;M01:P0:Z+Nj9qTZJMw=;wD4o8hBW5Z64TPZupDGKkXPTG1G kimdlcaS0RmmJaMxqu6iI5Gf/lmynmPnYHeugXSz7sJKMK1J94u1JxrGOLladWJ+qHa8zE7GI yj4ETh39AyOuXY0MRvEy5DAcGtpDMsZQHGb0P4v4qcBrHkZ/N2n+8pF4kR12pNvisVGXqJrbx AogthJbBcWoOuhMEnyc/m+WZs+hOvKJERm5lklAMjjqzmgdM9fSlKOj2UBCDpjHoIEdVHx+dk oYuVK1L96lCHlCfcKObFi+1dOKQ8An2THzExonzFsMevFJIkUKKfSfgAxePYIsv61fHLhm067 jggkVFprDWjRNV1QGHHB9ld4xlARXlFO/11e7xjctwitXkT+hOKrFYbnhwurTo43T7anXKchI gViLFwTmfM6GVsllRZbSSfHRIzP+3x/nkyIKWfqOGt0L4OWT00dA5atl3+6DKpHsBkdnAP4GB 8TJUb4qYH8L4mmNT6DxxRqXwsbgoA+ks8G8jgXyBp6JYSBHkOui3vBJ3dc1IpLixTbVD+5ZAZ qiLzEDlIa0L6rRIGCSqdBZYQ4FMpwzt6ASitigP4T5fcOdYmdxN5jUpzrhFxxpFYIL7P/40qV AD//q9u4V2iyjfX1V7vJkoyxy3azW5suTMYiqSUGMCMNE1AU9x8CSmn0zURo8eC8LNF3A0TMP mE4nlFHw5M9mLGCJ+6FHI2W1t5KSy92TaAUoQIDHJo6dFzNZLLMXd6xiQV0X+CGi0jb1pCwUd NdHCX3goTuRanl/7qDPYmN0GYam8JF4iL0YNSWfUxlZ/MfoXKW2D9pFD7e58mr2C4/MgMo538 7DZW6fbtNepU6myjrvcvLqUw== Content-Type: text/plain; charset="utf-8" On Mon, 2024-09-16 at 12:00 +0530, Venkat Rao Bagalkote wrote: > Greetings!!! Greetings, > I am seeing below kernel crash from 6.11.0-rc4-next-20240820. > > > Tried to do git bisect, but it didnt point to right patch. Attached is > the bisect log. > > Any help in fixing this is much appriciated. I met this, as well as other ways the wheels can fall off that turned out to have the same root. I gave Peter a heads up with diag offline, but having now convinced myself that all is well, I'll go ahead and post a patchlet. At the very least it's worth putting out for wider testing.. and should anyone have something prettier in mind, yeah, do that instead. sched: Fix sched_delayed vs cfs_bandwidth Meeting an unfinished DELAY_DEQUEUE treated entity in unthrottle_cfs_rq() leads to a couple terminal scenarios. Finish it first, so ENQUEUE_WAKEUP can proceed as it would have sans DELAY_DEQUEUE treatment. Fixes: 152e11f6df29 ("sched/fair: Implement delayed dequeue") Signed-off-by: Mike Galbraith Reported-by: Venkat Rao Bagalkote Tested-by: Venkat Rao Bagalkote --- kernel/sched/fair.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6049,10 +6049,14 @@ void unthrottle_cfs_rq(struct cfs_rq *cf for_each_sched_entity(se) { struct cfs_rq *qcfs_rq =3D cfs_rq_of(se); - if (se->on_rq) { - SCHED_WARN_ON(se->sched_delayed); - break; + /* Handle any unfinished DELAY_DEQUEUE business first. */ + if (unlikely(se->on_rq && se->sched_delayed)) { + int flags =3D DEQUEUE_SLEEP | DEQUEUE_SPECIAL; + + dequeue_entity(qcfs_rq, se, flags | DEQUEUE_DELAYED); } + if (se->on_rq) + break; enqueue_entity(qcfs_rq, se, ENQUEUE_WAKEUP); if (cfs_rq_is_idle(group_cfs_rq(se)))