From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from esa1.hgst.iphmx.com ([68.232.141.245]:57204 "EHLO esa1.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751192AbdFEXzY (ORCPT ); Mon, 5 Jun 2017 19:55:24 -0400 From: Bart Van Assche To: "hch@infradead.org" , "linux-block@vger.kernel.org" , "axboe@fb.com" , "ming.lei@redhat.com" Subject: Re: [PATCH v4 10/11] blk-mq: clarify dispatch may not be drained/blocked by stopping queue Date: Mon, 5 Jun 2017 23:55:20 +0000 Message-ID: <1496706919.2623.36.camel@sandisk.com> References: <20170605155925.7896-1-ming.lei@redhat.com> <20170605155925.7896-11-ming.lei@redhat.com> In-Reply-To: <20170605155925.7896-11-ming.lei@redhat.com> Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Sender: linux-block-owner@vger.kernel.org List-Id: linux-block@vger.kernel.org On Mon, 2017-06-05 at 23:59 +0800, Ming Lei wrote: > +/* > + * We do not guarantee that dispatch can be drained or blocked > + * after blk_mq_stop_hw_queue() returns. Please use > + * blk_mq_quiesce_queue() for that requirement. > + */ Hello Ming, This is comment explains what blk_mq_stop_hw_queue() should not be used for and may leave the reader wondering what it is useful for. How about mention= ing first that this function is useful to pause .queue_rq() calls as long as th= e block driver it will have to return BUSY if .queue_rq() is called? Bart.=