From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: 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 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> Sender: linux-block-owner@vger.kernel.org List-Id: linux-block@vger.kernel.org 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); -- 2.9.4