tmakin/ack-tegra
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

block: change plugging to use a singly linked list

Browse Source 
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>
This commit is contained in:
Jens Axboe
2021-10-18 10:12:12 -06:00
parent 480d42dc00
commit bc490f8173
4 changed files with 50 additions and 41 deletions
Download Patch File Download Diff File Expand all files Collapse all files
include/linux/blkdev.h
+2 -3
View File
@@ -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);