diff options
| author | Jens Axboe <axboe@kernel.dk> | 2021-10-18 10:12:12 -0600 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-10-19 09:21:42 -0600 |
| commit | bc490f81731e181b07b8d7577425c06ae91692c8 (patch) | |
| tree | abe26a3d3c309e8a5d62e61e50ccd8a13036aebb /block/blk-merge.c | |
| parent | 480d42dc001bbfe953825a92073012fcd5a99161 (diff) | |
block: change plugging to use a singly linked list
Use a singly linked list for the blk_plug. This saves 8 bytes in the
blk_plug struct, and makes for faster list manipulations than doubly
linked lists. As we don't use the doubly linked lists for anything,
singly linked is just fine.
This yields a bump in default (merging enabled) performance from 7.0
to 7.1M IOPS, and ~7.5M IOPS with merging disabled.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-merge.c')
| -rw-r--r-- | block/blk-merge.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/block/blk-merge.c b/block/blk-merge.c index c273b58378ce..3e6fa449caff 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -1090,11 +1090,11 @@ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, struct request *rq; plug = blk_mq_plug(q, bio); - if (!plug || list_empty(&plug->mq_list)) + if (!plug || rq_list_empty(plug->mq_list)) return false; /* check the previously added entry for a quick merge attempt */ - rq = list_last_entry(&plug->mq_list, struct request, queuelist); + rq = rq_list_peek(&plug->mq_list); if (rq->q == q) { /* * Only blk-mq multiple hardware queues case checks the rq in |