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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 1204DC43603 for ; Mon, 9 Dec 2019 16:58:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DBBEF2077B for ; Mon, 9 Dec 2019 16:58:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726379AbfLIQ6O (ORCPT ); Mon, 9 Dec 2019 11:58:14 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:1950 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725904AbfLIQ6O (ORCPT ); Mon, 9 Dec 2019 11:58:14 -0500 Received: from pps.filterd (m0098404.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id xB9GlSYB127293 for ; Mon, 9 Dec 2019 11:58:13 -0500 Received: from e06smtp03.uk.ibm.com (e06smtp03.uk.ibm.com [195.75.94.99]) by mx0a-001b2d01.pphosted.com with ESMTP id 2wrtfqhfc8-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 09 Dec 2019 11:58:12 -0500 Received: from localhost by e06smtp03.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) Mon, 9 Dec 2019 16:58:04 -0000 Received: from d06av25.portsmouth.uk.ibm.com (d06av25.portsmouth.uk.ibm.com [9.149.105.61]) by b06avi18878370.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id xB9Gw3NS44696048 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 9 Dec 2019 16:58:04 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D612411C050; Mon, 9 Dec 2019 16:58:03 +0000 (GMT) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 01B8111C04A; Mon, 9 Dec 2019 16:58:01 +0000 (GMT) Received: from linux.vnet.ibm.com (unknown [9.126.150.29]) by d06av25.portsmouth.uk.ibm.com (Postfix) with SMTP; Mon, 9 Dec 2019 16:58:00 +0000 (GMT) Date: Mon, 9 Dec 2019 22:28:00 +0530 From: Srikar Dronamraju To: Jens Axboe Cc: Boaz Harrosh , Phil Auld , Ming Lei , Peter Zijlstra , Dave Chinner , 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 , Ingo Molnar , Tejun Heo , Vincent Guittot Subject: Re: single aio thread is migrated crazily by scheduler Reply-To: Srikar Dronamraju References: <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> <20191121041218.GK24548@ming.t460p> <20191121141207.GA18443@pauld.bos.csb> <93de0f75-3664-c71e-9947-5b37ae935ddc@plexistor.com> <8c02ab43-3880-68db-f293-9958510fb29e@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <8c02ab43-3880-68db-f293-9958510fb29e@kernel.dk> User-Agent: Mutt/1.10.1 (2018-07-13) X-TM-AS-GCONF: 00 x-cbid: 19120916-0012-0000-0000-000003733800 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19120916-0013-0000-0000-000021AF077F Message-Id: <20191209165800.GB27229@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.95,18.0.572 definitions=2019-12-09_04:2019-12-09,2019-12-09 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=953 suspectscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 phishscore=0 malwarescore=0 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-1910280000 definitions=main-1912090142 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org * Jens Axboe [2019-11-21 09:19:29]: > > > > I wish there was a flag to wake_up() or to the event object that says > > to relinquish the remaning of the time-slice to the waiter on same > > CPU, since I will be soon sleeping. > > Isn't that basically what wake_up_sync() is? > Workqueue don't seem to be using wait_queue_head which is needed when using wake_up_sync and its related APIs. Also wake_up_sync would work when the waking task seems to hand off the CPU and goes to sleep/block. However here, i.e in fsperf case atleast, the waking thread continues to run after it has woken the per cpu workqueue. -- Thanks and Regards Srikar Dronamraju