From patchwork Fri May 26 03:07:38 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 9749665 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 2F1C860388 for ; Fri, 26 May 2017 03:08:42 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2B71C2833C for ; Fri, 26 May 2017 03:08:42 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 204712836F; Fri, 26 May 2017 03:08:42 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 477492833E for ; Fri, 26 May 2017 03:08:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S937022AbdEZDIk (ORCPT ); Thu, 25 May 2017 23:08:40 -0400 Received: from mx1.redhat.com ([209.132.183.28]:43546 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S937011AbdEZDIj (ORCPT ); Thu, 25 May 2017 23:08:39 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C6C01804E2; Fri, 26 May 2017 03:08:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com C6C01804E2 Authentication-Results: ext-mx03.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx03.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=ming.lei@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com C6C01804E2 Received: from localhost (ovpn-12-44.pek2.redhat.com [10.72.12.44]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9B9F55DD60; Fri, 26 May 2017 03:08:32 +0000 (UTC) From: Ming Lei To: Jens Axboe , linux-block@vger.kernel.org, Christoph Hellwig Cc: Bart Van Assche , linux-nvme@lists.infradead.org, linux-scsi@vger.kernel.org, dm-devel@redhat.com Subject: [PATCH 5/6] blk-mq: don't stop queue for quiescing Date: Fri, 26 May 2017 11:07:38 +0800 Message-Id: <20170526030740.26959-6-ming.lei@redhat.com> In-Reply-To: <20170526030740.26959-1-ming.lei@redhat.com> References: <20170526030740.26959-1-ming.lei@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Fri, 26 May 2017 03:08:39 +0000 (UTC) Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Now we use the QUIESCED flag to drain & block dispatching, not necessary to stop queue any more. Also queue can be started by other blk-mq APIs, this limits uses of blk_mq_quiesce_queue(). Now blk_mq_quiesce_queue() can be used safely and users won't worry about queue restart during quiescing. Signed-off-by: Ming Lei --- block/blk-mq.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index e1fc9ab50c87..900eb91e0ece 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -168,8 +168,6 @@ void blk_mq_quiesce_queue(struct request_queue *q) unsigned int i; bool rcu = false; - __blk_mq_stop_hw_queues(q, true); - spin_lock_irq(q->queue_lock); queue_flag_set(QUEUE_FLAG_QUIESCED, q); spin_unlock_irq(q->queue_lock); @@ -198,7 +196,12 @@ void blk_mq_unquiesce_queue(struct request_queue *q) queue_flag_clear(QUEUE_FLAG_QUIESCED, q); spin_unlock_irq(q->queue_lock); - blk_mq_start_stopped_hw_queues(q, true); + /* + * During quiescing, requests can be inserted + * to scheduler queue or sw queue, so we run + * queues for dispatching these requests. + */ + blk_mq_start_hw_queues(q); } EXPORT_SYMBOL_GPL(blk_mq_unquiesce_queue);