Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751670AbaKCIX3 (ORCPT ); Mon, 3 Nov 2014 03:23:29 -0500 Received: from casper.infradead.org ([85.118.1.10]:54724 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750910AbaKCIXX (ORCPT ); Mon, 3 Nov 2014 03:23:23 -0500 From: Christoph Hellwig To: Jens Axboe Cc: Richard Weinberger , Ming Lei , ceph-devel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 2/2] blk-mq: allow direct dispatch to a driver specific workqueue Date: Mon, 3 Nov 2014 09:23:28 +0100 Message-Id: <1415003008-16683-3-git-send-email-hch@lst.de> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1415003008-16683-1-git-send-email-hch@lst.de> References: <1415003008-16683-1-git-send-email-hch@lst.de> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We have various block drivers that need to execute long term blocking operations during I/O submission like file system or network I/O. Currently these drivers just queue up work to an internal workqueue from their request_fn. With blk-mq we can make sure they always get called on their own workqueue directly for I/O submission by: 1) adding a flag to prevent inline submission of I/O, and 2) allowing the driver to pass in a workqueue in the tag_set that will be used instead of kblockd. Signed-off-by: Christoph Hellwig --- block/blk-core.c | 2 +- block/blk-mq.c | 12 +++++++++--- block/blk.h | 1 + include/linux/blk-mq.h | 4 ++++ 4 files changed, 15 insertions(+), 4 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 0421b53..7f7249f 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -61,7 +61,7 @@ struct kmem_cache *blk_requestq_cachep; /* * Controlling structure to kblockd */ -static struct workqueue_struct *kblockd_workqueue; +struct workqueue_struct *kblockd_workqueue; void blk_queue_congestion_threshold(struct request_queue *q) { diff --git a/block/blk-mq.c b/block/blk-mq.c index 22e50a5..3d27d22 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -804,12 +804,13 @@ void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state))) return; - if (!async && cpumask_test_cpu(smp_processor_id(), hctx->cpumask)) { + if (!async && !(hctx->flags & BLK_MQ_F_WORKQUEUE) && + cpumask_test_cpu(smp_processor_id(), hctx->cpumask)) { __blk_mq_run_hw_queue(hctx); return; } - kblockd_schedule_delayed_work_on(blk_mq_hctx_next_cpu(hctx), + queue_delayed_work_on(blk_mq_hctx_next_cpu(hctx), hctx->wq, &hctx->run_work, 0); } @@ -908,7 +909,7 @@ static void blk_mq_delay_work_fn(struct work_struct *work) void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs) { - kblockd_schedule_delayed_work_on(blk_mq_hctx_next_cpu(hctx), + queue_delayed_work_on(blk_mq_hctx_next_cpu(hctx), hctx->wq, &hctx->delay_work, msecs_to_jiffies(msecs)); } EXPORT_SYMBOL(blk_mq_delay_queue); @@ -1581,6 +1582,11 @@ static int blk_mq_init_hctx(struct request_queue *q, hctx->flags = set->flags; hctx->cmd_size = set->cmd_size; + if (set->wq) + hctx->wq = set->wq; + else + hctx->wq = kblockd_workqueue; + blk_mq_init_cpu_notifier(&hctx->cpu_notifier, blk_mq_hctx_notify, hctx); blk_mq_register_cpu_notifier(&hctx->cpu_notifier); diff --git a/block/blk.h b/block/blk.h index 43b0361..fb46ad0 100644 --- a/block/blk.h +++ b/block/blk.h @@ -25,6 +25,7 @@ struct blk_flush_queue { spinlock_t mq_flush_lock; }; +extern struct workqueue_struct *kblockd_workqueue; extern struct kmem_cache *blk_requestq_cachep; extern struct kmem_cache *request_cachep; extern struct kobj_type blk_queue_ktype; diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 5a901d0..ebe4699 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -37,6 +37,8 @@ struct blk_mq_hw_ctx { unsigned int queue_num; struct blk_flush_queue *fq; + struct workqueue_struct *wq; + void *driver_data; struct blk_mq_ctxmap ctx_map; @@ -64,6 +66,7 @@ struct blk_mq_hw_ctx { struct blk_mq_tag_set { struct blk_mq_ops *ops; + struct workqueue_struct *wq; unsigned int nr_hw_queues; unsigned int queue_depth; /* max hw supported */ unsigned int reserved_tags; @@ -156,6 +159,7 @@ enum { BLK_MQ_F_SG_MERGE = 1 << 2, BLK_MQ_F_SYSFS_UP = 1 << 3, BLK_MQ_F_DEFER_ISSUE = 1 << 4, + BLK_MQ_F_WORKQUEUE = 1 << 5, BLK_MQ_S_STOPPED = 0, BLK_MQ_S_TAG_ACTIVE = 1, -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/