diff options
author | Jens Axboe <axboe@kernel.dk> | 2021-12-03 14:48:53 +0100 |
---|---|---|
committer | Jens Axboe <axboe@kernel.dk> | 2021-12-16 16:49:17 +0100 |
commit | 3c67d44de787dff288d7f2a51c372b22f7356db6 (patch) | |
tree | 98a6604327a08c080282c6ca40d5e12783a8eb7d /block | |
parent | block: use singly linked list for bio cache (diff) | |
download | linux-3c67d44de787dff288d7f2a51c372b22f7356db6.tar.xz linux-3c67d44de787dff288d7f2a51c372b22f7356db6.zip |
block: add mq_ops->queue_rqs hook
If we have a list of requests in our plug list, send it to the driver in
one go, if possible. The driver must set mq_ops->queue_rqs() to support
this, if not the usual one-by-one path is used.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
-rw-r--r-- | block/blk-mq.c | 26 |
1 files changed, 23 insertions, 3 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c index 75154cc788db..51991232824a 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2553,6 +2553,7 @@ void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) { struct blk_mq_hw_ctx *this_hctx; struct blk_mq_ctx *this_ctx; + struct request *rq; unsigned int depth; LIST_HEAD(list); @@ -2561,7 +2562,28 @@ void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) plug->rq_count = 0; if (!plug->multiple_queues && !plug->has_elevator && !from_schedule) { - struct request_queue *q = rq_list_peek(&plug->mq_list)->q; + struct request_queue *q; + + rq = rq_list_peek(&plug->mq_list); + q = rq->q; + + /* + * Peek first request and see if we have a ->queue_rqs() hook. + * If we do, we can dispatch the whole plug list in one go. We + * already know at this point that all requests belong to the + * same queue, caller must ensure that's the case. + * + * Since we pass off the full list to the driver at this point, + * we do not increment the active request count for the queue. + * Bypass shared tags for now because of that. + */ + if (q->mq_ops->queue_rqs && + !(rq->mq_hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) { + blk_mq_run_dispatch_ops(q, + q->mq_ops->queue_rqs(&plug->mq_list)); + if (rq_list_empty(plug->mq_list)) + return; + } blk_mq_run_dispatch_ops(q, blk_mq_plug_issue_direct(plug, false)); @@ -2573,8 +2595,6 @@ void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) this_ctx = NULL; depth = 0; do { - struct request *rq; - rq = rq_list_pop(&plug->mq_list); if (!this_hctx) { |