Commit 422765c2 authored by Jianpeng Ma's avatar Jianpeng Ma Committed by Jens Axboe
Browse files

block: Remove should_sort judgement when flush blk_plug 



In commit 975927b9,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: default avatarJianpeng Ma <majianpeng@gmail.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 242d98f0

block/blk-core.c

+1 −12
Original line number Diff line number Diff line
@@ -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;

	}



	q = NULL;

	depth = 0;

include/linux/blkdev.h

+0 −1
Original line number Diff line number Diff line
@@ -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

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