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From: Christoph Hellwig <hch@lst.de>
To: unlisted-recipients:; (no To-header on input)
Cc: linux-block@vger.kernel.org, John Garry <john.garry@huawei.com>,
	Bart Van Assche <bvanassche@acm.org>,
	Hannes Reinecke <hare@suse.com>,
	Thomas Gleixner <tglx@linutronix.de>
Subject: [PATCH 3/9] blk-mq: simplify the blk_mq_get_request calling convention
Date: Mon, 18 May 2020 08:39:31 +0200
Message-ID: <20200518063937.757218-4-hch@lst.de> (raw)
In-Reply-To: <20200518063937.757218-1-hch@lst.de>

The bio argument is entirely unused, and the request_queue can be passed
through the alloc_data, given that it needs to be filled out for the
low-level tag allocation anyway.  Also rename the function to
__blk_mq_alloc_request as the switch between get and alloc in the call
chains is rather confusing.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-mq.c | 36 ++++++++++++++++++++++--------------
 1 file changed, 22 insertions(+), 14 deletions(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 341af7752c509..ef8f50cdab858 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -332,10 +332,9 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
 	return rq;
 }
 
-static struct request *blk_mq_get_request(struct request_queue *q,
-					  struct bio *bio,
-					  struct blk_mq_alloc_data *data)
+static struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data)
 {
+	struct request_queue *q = data->q;
 	struct elevator_queue *e = q->elevator;
 	struct request *rq;
 	unsigned int tag;
@@ -346,7 +345,6 @@ static struct request *blk_mq_get_request(struct request_queue *q,
 	if (blk_queue_rq_alloc_time(q))
 		alloc_time_ns = ktime_get_ns();
 
-	data->q = q;
 	if (likely(!data->ctx)) {
 		data->ctx = blk_mq_get_ctx(q);
 		clear_ctx_on_error = true;
@@ -398,7 +396,11 @@ static struct request *blk_mq_get_request(struct request_queue *q,
 struct request *blk_mq_alloc_request(struct request_queue *q, unsigned int op,
 		blk_mq_req_flags_t flags)
 {
-	struct blk_mq_alloc_data alloc_data = { .flags = flags, .cmd_flags = op };
+	struct blk_mq_alloc_data data = {
+		.q		= q,
+		.flags		= flags,
+		.cmd_flags	= op,
+	};
 	struct request *rq;
 	int ret;
 
@@ -406,7 +408,7 @@ struct request *blk_mq_alloc_request(struct request_queue *q, unsigned int op,
 	if (ret)
 		return ERR_PTR(ret);
 
-	rq = blk_mq_get_request(q, NULL, &alloc_data);
+	rq = __blk_mq_alloc_request(&data);
 	if (!rq)
 		goto out_queue_exit;
 	rq->__data_len = 0;
@@ -422,7 +424,11 @@ EXPORT_SYMBOL(blk_mq_alloc_request);
 struct request *blk_mq_alloc_request_hctx(struct request_queue *q,
 	unsigned int op, blk_mq_req_flags_t flags, unsigned int hctx_idx)
 {
-	struct blk_mq_alloc_data alloc_data = { .flags = flags, .cmd_flags = op };
+	struct blk_mq_alloc_data data = {
+		.q		= q,
+		.flags		= flags,
+		.cmd_flags	= op,
+	};
 	struct request *rq;
 	unsigned int cpu;
 	int ret;
@@ -448,14 +454,14 @@ struct request *blk_mq_alloc_request_hctx(struct request_queue *q,
 	 * If not tell the caller that it should skip this queue.
 	 */
 	ret = -EXDEV;
-	alloc_data.hctx = q->queue_hw_ctx[hctx_idx];
-	if (!blk_mq_hw_queue_mapped(alloc_data.hctx))
+	data.hctx = q->queue_hw_ctx[hctx_idx];
+	if (!blk_mq_hw_queue_mapped(data.hctx))
 		goto out_queue_exit;
-	cpu = cpumask_first_and(alloc_data.hctx->cpumask, cpu_online_mask);
-	alloc_data.ctx = __blk_mq_get_ctx(q, cpu);
+	cpu = cpumask_first_and(data.hctx->cpumask, cpu_online_mask);
+	data.ctx = __blk_mq_get_ctx(q, cpu);
 
 	ret = -EWOULDBLOCK;
-	rq = blk_mq_get_request(q, NULL, &alloc_data);
+	rq = __blk_mq_alloc_request(&data);
 	if (!rq)
 		goto out_queue_exit;
 	return rq;
@@ -1987,7 +1993,9 @@ blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
 {
 	const int is_sync = op_is_sync(bio->bi_opf);
 	const int is_flush_fua = op_is_flush(bio->bi_opf);
-	struct blk_mq_alloc_data data = { .flags = 0};
+	struct blk_mq_alloc_data data = {
+		.q		= q,
+	};
 	struct request *rq;
 	struct blk_plug *plug;
 	struct request *same_queue_rq = NULL;
@@ -2011,7 +2019,7 @@ blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
 	rq_qos_throttle(q, bio);
 
 	data.cmd_flags = bio->bi_opf;
-	rq = blk_mq_get_request(q, bio, &data);
+	rq = __blk_mq_alloc_request(&data);
 	if (unlikely(!rq)) {
 		rq_qos_cleanup(q, bio);
 		if (bio->bi_opf & REQ_NOWAIT)
-- 
2.26.2


  parent reply index

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-18  6:39 blk-mq: improvement CPU hotplug (simplified version) v2 Christoph Hellwig
2020-05-18  6:39 ` [PATCH 1/9] blk-mq: split out a __blk_mq_get_driver_tag helper Christoph Hellwig
2020-05-18  6:39 ` [PATCH 2/9] blk-mq: remove the bio argument to ->prepare_request Christoph Hellwig
2020-05-18  6:39 ` Christoph Hellwig [this message]
2020-05-18  6:39 ` [PATCH 4/9] blk-mq: merge blk_mq_rq_ctx_init into __blk_mq_alloc_request Christoph Hellwig
2020-05-18  6:39 ` [PATCH 5/9] blk-mq: don't set data->ctx and data->hctx in blk_mq_alloc_request_hctx Christoph Hellwig
2020-05-18  8:32   ` Thomas Gleixner
2020-05-18  9:31     ` Ming Lei
2020-05-18 10:42       ` Thomas Gleixner
2020-05-18 11:54         ` Ming Lei
2020-05-18 13:16           ` Christoph Hellwig
2020-05-18 14:11             ` Ming Lei
2020-05-18 16:56               ` Christoph Hellwig
2020-05-18 18:38                 ` Thomas Gleixner
2020-05-18 18:45                   ` Christoph Hellwig
2020-05-18 18:59                     ` Thomas Gleixner
2020-05-19  1:54                 ` Ming Lei
2020-05-19 15:30                   ` Christoph Hellwig
2020-05-20  1:18                     ` Ming Lei
2020-05-20  3:04                       ` Ming Lei
2020-05-20  8:03                         ` io_uring vs CPU hotplug, was " Christoph Hellwig
2020-05-20 14:45                           ` Jens Axboe
2020-05-20 15:20                             ` Jens Axboe
2020-05-20 15:31                               ` Christoph Hellwig
2020-05-20 19:41                               ` Thomas Gleixner
2020-05-20 20:18                                 ` Jens Axboe
2020-05-20 22:14                                   ` Thomas Gleixner
2020-05-20 22:40                                     ` Jens Axboe
2020-05-21  2:27                                     ` Ming Lei
2020-05-21  8:13                                       ` Thomas Gleixner
2020-05-21  9:23                                         ` Ming Lei
2020-05-21 18:39                                           ` Thomas Gleixner
2020-05-21 18:45                                             ` Jens Axboe
2020-05-21 20:00                                               ` Thomas Gleixner
2020-05-22  1:57                                             ` Ming Lei
2020-05-18 18:47             ` Thomas Gleixner
2020-05-18 13:18           ` Thomas Gleixner
2020-05-18  6:39 ` [PATCH 6/9] blk-mq: don't set data->ctx and data->hctx in __blk_mq_alloc_request Christoph Hellwig
2020-05-18  6:39 ` [PATCH 7/9] blk-mq: disable preemption during allocating request tag Christoph Hellwig
2020-05-18  6:39 ` [PATCH 8/9] blk-mq: add blk_mq_all_tag_iter Christoph Hellwig
2020-05-18  6:39 ` [PATCH 9/9] blk-mq: drain I/O when all CPUs in a hctx are offline Christoph Hellwig
2020-05-18  8:42   ` John Garry
2020-05-18  9:21     ` Ming Lei
2020-05-18 11:49 ` blk-mq: improvement CPU hotplug (simplified version) v2 John Garry
2020-05-19 15:30   ` Christoph Hellwig
2020-05-19 17:17     ` John Garry
2020-05-20 14:35     ` John Garry

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