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=-3.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, T_DKIMWL_WL_HIGH,UNPARSEABLE_RELAY,USER_AGENT_GIT autolearn=ham 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 4F8A2C4321D for ; Fri, 17 Aug 2018 03:53:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 085BE20852 for ; Fri, 17 Aug 2018 03:53:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="0zkKVvUn" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 085BE20852 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=oracle.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726398AbeHQGzh (ORCPT ); Fri, 17 Aug 2018 02:55:37 -0400 Received: from aserp2130.oracle.com ([141.146.126.79]:60704 "EHLO aserp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725833AbeHQGzh (ORCPT ); Fri, 17 Aug 2018 02:55:37 -0400 Received: from pps.filterd (aserp2130.oracle.com [127.0.0.1]) by aserp2130.oracle.com (8.16.0.22/8.16.0.22) with SMTP id w7H3muFs124587; Fri, 17 Aug 2018 03:52:49 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id; s=corp-2018-07-02; bh=HBXZteOn3R7CuYN54xc5nlLjbRbupbNyrcvISv3A5/A=; b=0zkKVvUnih0qMa/Mt2j2WOWGDjey1vv7CLjo37BBx51v+f6b1Xs8xI7vcSDNIKEaJF7h yNbYqaTqvvcjd7oe1UdSVmtZB0M6ATNy38Xk9U4YkGwhDrdol7H+/yrYv7C9WZ/5x7ja OWNqyrmS3Hs5WfdHirkvE9R6JBpmYerfHPh13jaBeGTVlLOUSo5ciJIOQaYcUsLay5ie +3gKHZR7OaVOxs/VWvy/E/p9vZQnKZWKvkWDvazU3a86EcF8mu0L2O4CEQ7jGmptz0az zaT7GssY8PEG6RfFp/iZAZsXSEhLdRUKIh4aNzBoBgz9u7fwug3+y0wR0lmdnvv4iE7w /A== Received: from userv0022.oracle.com (userv0022.oracle.com [156.151.31.74]) by aserp2130.oracle.com with ESMTP id 2ksnaddnm2-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 17 Aug 2018 03:52:49 +0000 Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by userv0022.oracle.com (8.14.4/8.14.4) with ESMTP id w7H3qm4u014935 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 17 Aug 2018 03:52:48 GMT Received: from abhmp0003.oracle.com (abhmp0003.oracle.com [141.146.116.9]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id w7H3qlCg019330; Fri, 17 Aug 2018 03:52:47 GMT Received: from will-ThinkCentre-M910s.cn.oracle.com (/10.182.70.254) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 16 Aug 2018 20:52:46 -0700 From: Jianchao Wang To: axboe@kernel.dk Cc: tom.leiming@gmail.com, bart.vanassche@wdc.com, keith.busch@linux.intel.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH V2 0/2] fixes for the updating nr_hw_queues Date: Fri, 17 Aug 2018 11:54:01 +0800 Message-Id: <1534478043-7170-1-git-send-email-jianchao.w.wang@oracle.com> X-Mailer: git-send-email 2.7.4 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8987 signatures=668707 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=1 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=777 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1808170040 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jens Two fixes for updating nr_hw_queues. The first patch fixes the following scenario: io scheduler (kyber) depends on the mapping between ctx and hctx. When update nr_hw_queues, io scheduler's init_hctx will be invoked before the mapping is adapted correctly, this would cause panic in kyber. The second patch fixes the following scenario: part_in_flight/rw will invoke blk_mq_in_flight/rw to account the inflight requests. It will access the queue_hw_ctx and nr_hw_queues w/o any protection. When updating nr_hw_queues and blk_mq_in_flight /rw occur concurrently, panic comes up. V2: - remove blk_mq_sched_init/exit_hctx in patch 1. - use q_usage_counter instead of adding new member suggested by Ming in patch 2. - comment modification. Jianchao Wang(2) blk-mq: init hctx sched after update ctx and hctx mapping blk-mq: sync the update nr_hw_queues with part_in_flight block/blk-mq-sched.c | 44 ---------------------------------- block/blk-mq-sched.h | 5 ---- block/blk-mq.c | 65 +++++++++++++++++++++++++++++++++++++++++++------- block/blk.h | 2 ++ block/elevator.c | 20 +++++++++------- include/linux/blkdev.h | 3 +++ 6 files changed, 74 insertions(+), 65 deletions(-) Thanks Jianchao