diff options
| author | Jens Axboe <axboe@kernel.dk> | 2018-11-29 20:03:42 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2018-11-29 20:12:37 +0300 |
| commit | b2c5d16b72df1116f05c9be16a630ac939d34101 (patch) | |
| tree | 933ddf90cf418d93f6c0e0cb63c89cc7d925094e /block/blk-mq.c | |
| parent | be94f058f2bde6f0b0ee9059a35daa8e15be308f (diff) | |
| download | linux-b2c5d16b72df1116f05c9be16a630ac939d34101.tar.xz | |
blk-mq: use plug for devices that implement ->commits_rqs()
If we have that hook, we know the driver handles bd->last == true in
a smart fashion. If it does, even for multiple hardware queues, it's
a good idea to flush batches of requests to the device, if we have
batches of requests from the submitter.
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-mq.c')
| -rw-r--r-- | block/blk-mq.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c index 14e31e93a950..7dcef565dc0f 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1945,7 +1945,11 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) /* bypass scheduler for flush rq */ blk_insert_flush(rq); blk_mq_run_hw_queue(data.hctx, true); - } else if (plug && q->nr_hw_queues == 1) { + } else if (plug && (q->nr_hw_queues == 1 || q->mq_ops->commit_rqs)) { + /* + * Use plugging if we have a ->commit_rqs() hook as well, as + * we know the driver uses bd->last in a smart fashion. + */ unsigned int request_count = plug->rq_count; struct request *last = NULL; |