blk-mq: move more plug handling from blk_mq_submit_bio into blk_add_rq_to_plug

Keep all the functionality for adding a request to a plug in a single place.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211123160443.1315598-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Christoph Hellwig 2021-11-23 17:04:42 +01:00 committed by Jens Axboe
parent 0c5bcc92d9
commit 1e9c23034d

View File

@ -2662,21 +2662,6 @@ void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,
hctx->queue->mq_ops->commit_rqs(hctx);
}
static void blk_add_rq_to_plug(struct blk_plug *plug, struct request *rq)
{
if (!plug->multiple_queues) {
struct request *nxt = rq_list_peek(&plug->mq_list);
if (nxt && nxt->q != rq->q)
plug->multiple_queues = true;
}
if (!plug->has_elevator && (rq->rq_flags & RQF_ELV))
plug->has_elevator = true;
rq->rq_next = NULL;
rq_list_add(&plug->mq_list, rq);
plug->rq_count++;
}
/*
* Allow 2x BLK_MAX_REQUEST_COUNT requests on plug queue for multiple
* queues. This is important for md arrays to benefit from merging
@ -2689,6 +2674,28 @@ static inline unsigned short blk_plug_max_rq_count(struct blk_plug *plug)
return BLK_MAX_REQUEST_COUNT;
}
static void blk_add_rq_to_plug(struct blk_plug *plug, struct request *rq)
{
struct request *last = rq_list_peek(&plug->mq_list);
if (!plug->rq_count) {
trace_block_plug(rq->q);
} else if (plug->rq_count >= blk_plug_max_rq_count(plug) ||
(!blk_queue_nomerges(rq->q) &&
blk_rq_bytes(last) >= BLK_PLUG_FLUSH_SIZE)) {
blk_mq_flush_plug_list(plug, false);
trace_block_plug(rq->q);
}
if (!plug->multiple_queues && last && last->q != rq->q)
plug->multiple_queues = true;
if (!plug->has_elevator && (rq->rq_flags & RQF_ELV))
plug->has_elevator = true;
rq->rq_next = NULL;
rq_list_add(&plug->mq_list, rq);
plug->rq_count++;
}
static bool blk_mq_attempt_bio_merge(struct request_queue *q,
struct bio *bio, unsigned int nr_segs)
{
@ -2841,31 +2848,14 @@ void blk_mq_submit_bio(struct bio *bio)
return;
}
if (plug) {
unsigned int request_count = plug->rq_count;
struct request *last = NULL;
if (!request_count) {
trace_block_plug(q);
} else if (!blk_queue_nomerges(q)) {
last = rq_list_peek(&plug->mq_list);
if (blk_rq_bytes(last) < BLK_PLUG_FLUSH_SIZE)
last = NULL;
}
if (request_count >= blk_plug_max_rq_count(plug) || last) {
blk_mq_flush_plug_list(plug, false);
trace_block_plug(q);
}
if (plug)
blk_add_rq_to_plug(plug, rq);
} else if ((rq->rq_flags & RQF_ELV) ||
(rq->mq_hctx->dispatch_busy &&
(q->nr_hw_queues == 1 || !is_sync))) {
else if ((rq->rq_flags & RQF_ELV) ||
(rq->mq_hctx->dispatch_busy &&
(q->nr_hw_queues == 1 || !is_sync)))
blk_mq_sched_insert_request(rq, false, true, true);
} else {
else
blk_mq_try_issue_directly(rq->mq_hctx, rq);
}
}
/**