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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 298B2C2BD09 for ; Tue, 10 Dec 2019 03:27:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 09747206E0 for ; Tue, 10 Dec 2019 03:27:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726623AbfLJD1Y (ORCPT ); Mon, 9 Dec 2019 22:27:24 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:22148 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726619AbfLJD1Y (ORCPT ); Mon, 9 Dec 2019 22:27:24 -0500 Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id xBA3RABx109890 for ; Mon, 9 Dec 2019 22:27:23 -0500 Received: from e06smtp01.uk.ibm.com (e06smtp01.uk.ibm.com [195.75.94.97]) by mx0a-001b2d01.pphosted.com with ESMTP id 2wsnfe7ke5-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 09 Dec 2019 22:27:22 -0500 Received: from localhost by e06smtp01.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Tue, 10 Dec 2019 03:27:16 -0000 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06avi18878370.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id xBA3RFfO44630442 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 10 Dec 2019 03:27:15 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 7358552051; Tue, 10 Dec 2019 03:27:15 +0000 (GMT) Received: from linux.vnet.ibm.com (unknown [9.126.150.29]) by d06av21.portsmouth.uk.ibm.com (Postfix) with SMTP id BACC15204E; Tue, 10 Dec 2019 03:27:12 +0000 (GMT) Date: Tue, 10 Dec 2019 08:57:12 +0530 From: Srikar Dronamraju To: Dave Chinner Cc: Peter Zijlstra , Phil Auld , Ming Lei , linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-kernel@vger.kernel.org, Jeff Moyer , Dave Chinner , Eric Sandeen , Christoph Hellwig , Jens Axboe , Ingo Molnar , Tejun Heo , Vincent Guittot Subject: Re: single aio thread is migrated crazily by scheduler Reply-To: Srikar Dronamraju References: <20191115045634.GN4614@dread.disaster.area> <20191115070843.GA24246@ming.t460p> <20191115234005.GO4614@dread.disaster.area> <20191118092121.GV4131@hirez.programming.kicks-ass.net> <20191118204054.GV4614@dread.disaster.area> <20191120191636.GI4097@hirez.programming.kicks-ass.net> <20191120220313.GC18056@pauld.bos.csb> <20191121132937.GW4114@hirez.programming.kicks-ass.net> <20191209165122.GA27229@linux.vnet.ibm.com> <20191209231743.GA19256@dread.disaster.area> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20191209231743.GA19256@dread.disaster.area> User-Agent: Mutt/1.10.1 (2018-07-13) X-TM-AS-GCONF: 00 x-cbid: 19121003-4275-0000-0000-0000038D7597 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19121003-4276-0000-0000-000038A124D9 Message-Id: <20191210032712.GE27253@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.95,18.0.572 definitions=2019-12-09_05:2019-12-09,2019-12-09 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 bulkscore=0 adultscore=0 mlxlogscore=964 spamscore=0 clxscore=1015 phishscore=0 malwarescore=0 impostorscore=0 suspectscore=0 mlxscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-1910280000 definitions=main-1912100030 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org * Dave Chinner [2019-12-10 10:17:43]: > On Mon, Dec 09, 2019 at 10:21:22PM +0530, Srikar Dronamraju wrote: > > diff --git a/kernel/sched/core.c b/kernel/sched/core.c > > index 44123b4d14e8..efd740aafa17 100644 > > --- a/kernel/sched/core.c > > +++ b/kernel/sched/core.c > > @@ -2664,7 +2664,12 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) > > */ > > int wake_up_process(struct task_struct *p) > > { > > - return try_to_wake_up(p, TASK_NORMAL, 0); > > + int wake_flags = 0; > > + > > + if (is_per_cpu_kthread(p)) > > + wake_flags = WF_KTHREAD; > > + > > + return try_to_wake_up(p, TASK_NORMAL, WF_KTHREAD); > > This is buggy. It always sets WF_KTHREAD, even for non-kernel > processes. I think you meant: > > return try_to_wake_up(p, TASK_NORMAL, wake_flags); Yes, I meant the above. Thanks for catching. Will test with this and repost. > > I suspect this bug invalidates the test results presented, too... > > -Dave. > -- > Dave Chinner > david@fromorbit.com -- Thanks and Regards Srikar Dronamraju