block: Remove should_sort judgement when flush blk_plug

In commit 975927b942c932,it add blk_rq_pos to sort rq when flushing.
Although this commit was used for the situation which blk_plug handled
multi devices on the same time like md device.
I think there must be some situations like this but only single
device.
So remove the should_sort judgement.
Because the parameter should_sort is only for this purpose,it can delete
should_sort from blk_plug.

CC: Shaohua Li <shli@kernel.org>
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jianpeng Ma 2013-01-11 14:46:09 +01:00 committed by Jens Axboe
parent 242d98f077
commit 422765c263
2 changed files with 1 additions and 13 deletions

View file

@ -1548,13 +1548,6 @@ get_rq:
if (list_empty(&plug->list))
trace_block_plug(q);
else {
if (!plug->should_sort) {
struct request *__rq;
__rq = list_entry_rq(plug->list.prev);
if (__rq->q != q)
plug->should_sort = 1;
}
if (request_count >= BLK_MAX_REQUEST_COUNT) {
blk_flush_plug_list(plug, false);
trace_block_plug(q);
@ -2888,7 +2881,6 @@ void blk_start_plug(struct blk_plug *plug)
plug->magic = PLUG_MAGIC;
INIT_LIST_HEAD(&plug->list);
INIT_LIST_HEAD(&plug->cb_list);
plug->should_sort = 0;
/*
* If this is a nested plug, don't actually assign it. It will be
@ -2990,10 +2982,7 @@ void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
list_splice_init(&plug->list, &list);
if (plug->should_sort) {
list_sort(NULL, &list, plug_rq_cmp);
plug->should_sort = 0;
}
list_sort(NULL, &list, plug_rq_cmp);
q = NULL;
depth = 0;

View file

@ -974,7 +974,6 @@ struct blk_plug {
unsigned long magic; /* detect uninitialized use-cases */
struct list_head list; /* requests */
struct list_head cb_list; /* md requires an unplug callback */
unsigned int should_sort; /* list to be sorted before flushing? */
};
#define BLK_MAX_REQUEST_COUNT 16