From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from esa6.hgst.iphmx.com ([216.71.154.45]:37725 "EHLO esa6.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751188AbdFEVZd (ORCPT ); Mon, 5 Jun 2017 17:25:33 -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 01/11] blk-mq: fix direct issue Date: Mon, 5 Jun 2017 21:25:29 +0000 Message-ID: <1496697927.2623.23.camel@sandisk.com> References: <20170605155925.7896-1-ming.lei@redhat.com> <20170605155925.7896-2-ming.lei@redhat.com> In-Reply-To: <20170605155925.7896-2-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: > +static void __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, > + struct request *rq, > + blk_qc_t *cookie, bool may_sleep) > { > struct request_queue *q =3D rq->q; > struct blk_mq_queue_data bd =3D { > .rq =3D rq, > .last =3D true, > }; > - struct blk_mq_hw_ctx *hctx; > blk_qc_t new_cookie; > int ret; > + bool run_queue =3D true; > + > + if (blk_mq_hctx_stopped(hctx)) { > + run_queue =3D false; > + goto insert; > + } > =20 > if (q->elevator) > goto insert; > =20 > - if (!blk_mq_get_driver_tag(rq, &hctx, false)) > + if (!blk_mq_get_driver_tag(rq, NULL, false)) > goto insert; > =20 > new_cookie =3D request_to_qc_t(hctx, rq); > @@ -1439,7 +1445,7 @@ static void __blk_mq_try_issue_directly(struct requ= est *rq, blk_qc_t *cookie, > =20 > __blk_mq_requeue_request(rq); > insert: > - blk_mq_sched_insert_request(rq, false, true, false, may_sleep); > + blk_mq_sched_insert_request(rq, false, run_queue, false, may_sleep); > } > =20 > static void blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, > @@ -1447,7 +1453,7 @@ static void blk_mq_try_issue_directly(struct blk_mq= _hw_ctx *hctx, > { > if (!(hctx->flags & BLK_MQ_F_BLOCKING)) { > rcu_read_lock(); > - __blk_mq_try_issue_directly(rq, cookie, false); > + __blk_mq_try_issue_directly(hctx, rq, cookie, false); > rcu_read_unlock(); > } else { > unsigned int srcu_idx; > @@ -1455,7 +1461,7 @@ static void blk_mq_try_issue_directly(struct blk_mq= _hw_ctx *hctx, > might_sleep(); > =20 > srcu_idx =3D srcu_read_lock(&hctx->queue_rq_srcu); > - __blk_mq_try_issue_directly(rq, cookie, true); > + __blk_mq_try_issue_directly(hctx, rq, cookie, true); > srcu_read_unlock(&hctx->queue_rq_srcu, srcu_idx); > } > } Hello Ming, It seems like you are assuming that the hardware queue of the rq argument passed to __blk_mq_try_issue_directly() matches the hctx argument? Sorry but I think that's an incorrect assumption. Please have a look at the following code in blk_mq_make_request(): if (same_queue_rq) blk_mq_try_issue_directly(data.hctx, same_queue_rq, &cookie); Bart.=