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 4/6] blk-mq: open code __blk_mq_alloc_request in blk_mq_alloc_request_hctx
Date: Wed, 20 May 2020 19:06:33 +0200 [thread overview]
Message-ID: <20200520170635.2094101-5-hch@lst.de> (raw)
In-Reply-To: <20200520170635.2094101-1-hch@lst.de>
blk_mq_alloc_request_hctx is only used for NVMeoF connect commands, so
tailor it to the specific requirements, and don't both the general
fast path code with its special twinkles.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
block/blk-mq.c | 44 +++++++++++++++++++++++---------------------
1 file changed, 23 insertions(+), 21 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 1ffbc5d9e7cfe..42aee2978464b 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -351,21 +351,13 @@ 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;
- unsigned int tag;
- bool clear_ctx_on_error = false;
u64 alloc_time_ns = 0;
+ unsigned int tag;
/* alloc_time includes depth and tag waits */
if (blk_queue_rq_alloc_time(q))
alloc_time_ns = ktime_get_ns();
- if (likely(!data->ctx)) {
- data->ctx = blk_mq_get_ctx(q);
- clear_ctx_on_error = true;
- }
- if (likely(!data->hctx))
- data->hctx = blk_mq_map_queue(q, data->cmd_flags,
- data->ctx);
if (data->cmd_flags & REQ_NOWAIT)
data->flags |= BLK_MQ_REQ_NOWAIT;
@@ -381,17 +373,16 @@ static struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data)
e->type->ops.limit_depth &&
!(data->flags & BLK_MQ_REQ_RESERVED))
e->type->ops.limit_depth(data->cmd_flags, data);
- } else {
- blk_mq_tag_busy(data->hctx);
}
+ data->ctx = blk_mq_get_ctx(q);
+ data->hctx = blk_mq_map_queue(q, data->cmd_flags, data->ctx);
+ if (!(data->flags & BLK_MQ_REQ_INTERNAL))
+ blk_mq_tag_busy(data->hctx);
+
tag = blk_mq_get_tag(data);
- if (tag == BLK_MQ_TAG_FAIL) {
- if (clear_ctx_on_error)
- data->ctx = NULL;
+ if (tag == BLK_MQ_TAG_FAIL)
return NULL;
- }
-
return blk_mq_rq_ctx_init(data, tag, alloc_time_ns);
}
@@ -431,17 +422,22 @@ struct request *blk_mq_alloc_request_hctx(struct request_queue *q,
.flags = flags,
.cmd_flags = op,
};
- struct request *rq;
+ u64 alloc_time_ns = 0;
unsigned int cpu;
+ unsigned int tag;
int ret;
+ /* alloc_time includes depth and tag waits */
+ if (blk_queue_rq_alloc_time(q))
+ alloc_time_ns = ktime_get_ns();
+
/*
* If the tag allocator sleeps we could get an allocation for a
* different hardware context. No need to complicate the low level
* allocator for this for the rare use case of a command tied to
* a specific queue.
*/
- if (WARN_ON_ONCE(!(flags & BLK_MQ_REQ_NOWAIT)))
+ if (WARN_ON_ONCE(!(flags & (BLK_MQ_REQ_NOWAIT | BLK_MQ_REQ_RESERVED))))
return ERR_PTR(-EINVAL);
if (hctx_idx >= q->nr_hw_queues)
@@ -462,11 +458,17 @@ struct request *blk_mq_alloc_request_hctx(struct request_queue *q,
cpu = cpumask_first_and(data.hctx->cpumask, cpu_online_mask);
data.ctx = __blk_mq_get_ctx(q, cpu);
+ if (q->elevator)
+ data.flags |= BLK_MQ_REQ_INTERNAL;
+ else
+ blk_mq_tag_busy(data.hctx);
+
ret = -EWOULDBLOCK;
- rq = __blk_mq_alloc_request(&data);
- if (!rq)
+ tag = blk_mq_get_tag(&data);
+ if (tag == BLK_MQ_TAG_FAIL)
goto out_queue_exit;
- return rq;
+ return blk_mq_rq_ctx_init(&data, tag, alloc_time_ns);
+
out_queue_exit:
blk_queue_exit(q);
return ERR_PTR(ret);
--
2.26.2
next prev parent reply other threads:[~2020-05-20 17:06 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-20 17:06 blk-mq: improvement CPU hotplug (simplified version) v3 Christoph Hellwig
2020-05-20 17:06 ` [PATCH 1/6] blk-mq: remove the bio argument to ->prepare_request Christoph Hellwig
2020-05-20 18:16 ` Bart Van Assche
2020-05-22 9:11 ` Hannes Reinecke
2020-05-20 17:06 ` [PATCH 2/6] blk-mq: simplify the blk_mq_get_request calling convention Christoph Hellwig
2020-05-20 18:22 ` Bart Van Assche
2020-05-22 9:13 ` Hannes Reinecke
2020-05-20 17:06 ` [PATCH 3/6] blk-mq: move more request initialization to blk_mq_rq_ctx_init Christoph Hellwig
2020-05-20 20:10 ` Bart Van Assche
2020-05-20 17:06 ` Christoph Hellwig [this message]
2020-05-22 9:17 ` [PATCH 4/6] blk-mq: open code __blk_mq_alloc_request in blk_mq_alloc_request_hctx Hannes Reinecke
2020-05-20 17:06 ` [PATCH 5/6] blk-mq: add blk_mq_all_tag_iter Christoph Hellwig
2020-05-20 20:24 ` Bart Van Assche
2020-05-27 6:05 ` Christoph Hellwig
2020-05-22 9:18 ` Hannes Reinecke
2020-05-20 17:06 ` [PATCH 6/6] blk-mq: drain I/O when all CPUs in a hctx are offline Christoph Hellwig
2020-05-22 9:25 ` Hannes Reinecke
2020-05-25 9:20 ` Ming Lei
2020-05-20 21:46 ` blk-mq: improvement CPU hotplug (simplified version) v3 Bart Van Assche
2020-05-21 2:57 ` Ming Lei
2020-05-21 3:50 ` Bart Van Assche
2020-05-21 4:33 ` Ming Lei
2020-05-21 19:15 ` Bart Van Assche
2020-05-22 2:39 ` Ming Lei
2020-05-22 14:47 ` Keith Busch
2020-05-23 3:05 ` Ming Lei
2020-05-23 15:19 ` Bart Van Assche
2020-05-25 4:09 ` Ming Lei
2020-05-25 15:32 ` Bart Van Assche
2020-05-25 16:38 ` Keith Busch
2020-05-26 0:37 ` Ming Lei
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200520170635.2094101-5-hch@lst.de \
--to=hch@lst.de \
--cc=bvanassche@acm.org \
--cc=hare@suse.com \
--cc=john.garry@huawei.com \
--cc=linux-block@vger.kernel.org \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).