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 /include/linux/blkdev.h | |
| 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 'include/linux/blkdev.h')
| -rw-r--r-- | include/linux/blkdev.h | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index fd9771a1da09..4027112b9851 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -728,7 +728,7 @@ extern void blk_set_queue_dying(struct request_queue *); * schedule() where blk_schedule_flush_plug() is called. */ struct blk_plug { - struct list_head mq_list; /* blk-mq requests */ + struct request *mq_list; /* blk-mq requests */ /* if ios_left is > 1, we can batch tag/rq allocations */ struct request *cached_rq; @@ -777,8 +777,7 @@ static inline bool blk_needs_flush_plug(struct task_struct *tsk) struct blk_plug *plug = tsk->plug; return plug && - (!list_empty(&plug->mq_list) || - !list_empty(&plug->cb_list)); + (plug->mq_list || !list_empty(&plug->cb_list)); } int blkdev_issue_flush(struct block_device *bdev); |