korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-11 04:18:39 +08:00
Code Issues Packages Projects Releases Wiki Activity

[PATCH] use cheaper elv_queue_empty when unplug a device

Browse Source 
In function __generic_unplug_device(), kernel can use a cheaper function
elv_queue_empty() instead of more expensive elv_next_request to find
whether the queue is empty or not.  blk_run_queue can also made conditional
on whether queue's emptiness before calling request_fn().

Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Ken Chen 2005-04-16 15:25:43 -07:00 committed by Linus Torvalds
parent 975e046cc0
commit a299738283
1 changed files with 2 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
drivers/block/ll_rw_blk.c
View File

@ -1589,7 +1589,8 @@ void blk_run_queue(struct request_queue *q)
spin_lock_irqsave(q->queue_lock, flags);
blk_remove_plug(q);
q->request_fn(q);
if (!elv_queue_empty(q))
q->request_fn(q);
spin_unlock_irqrestore(q->queue_lock, flags);
}
EXPORT_SYMBOL(blk_run_queue);