Commit 65299a3b authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: separate priority boosting from REQ_META 



Add a new REQ_PRIO to let requests preempt others in the cfq I/O schedule,
and lave REQ_META purely for marking requests as metadata in blktrace.

All existing callers of REQ_META except for XFS are updated to also
set REQ_PRIO for now.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarNamhyung Kim <namhyung@gmail.com>
Signed-off-by: default avatarJens Axboe <jaxboe@fusionio.com>
parent 5dc06c5a

block/cfq-iosched.c

+10 −10
Original line number Diff line number Diff line
@@ -130,8 +130,8 @@ struct cfq_queue { 
	unsigned long slice_end;

	long slice_resid;



	/* pending metadata requests */

	int meta_pending;

	/* pending priority requests */

	int prio_pending;

	/* number of requests that are on the dispatch list or inside driver */

	int dispatched;
@@ -684,8 +684,8 @@ cfq_choose_req(struct cfq_data *cfqd, struct request *rq1, struct request *rq2, 
	if (rq_is_sync(rq1) != rq_is_sync(rq2))

		return rq_is_sync(rq1) ? rq1 : rq2;



	if ((rq1->cmd_flags ^ rq2->cmd_flags) & REQ_META)

		return rq1->cmd_flags & REQ_META ? rq1 : rq2;

	if ((rq1->cmd_flags ^ rq2->cmd_flags) & REQ_PRIO)

		return rq1->cmd_flags & REQ_PRIO ? rq1 : rq2;



	s1 = blk_rq_pos(rq1);

	s2 = blk_rq_pos(rq2);
@@ -1612,9 +1612,9 @@ static void cfq_remove_request(struct request *rq) 
	cfqq->cfqd->rq_queued--;

	cfq_blkiocg_update_io_remove_stats(&(RQ_CFQG(rq))->blkg,

					rq_data_dir(rq), rq_is_sync(rq));

	if (rq->cmd_flags & REQ_META) {

		WARN_ON(!cfqq->meta_pending);

		cfqq->meta_pending--;

	if (rq->cmd_flags & REQ_PRIO) {

		WARN_ON(!cfqq->prio_pending);

		cfqq->prio_pending--;

	}

}
@@ -3372,7 +3372,7 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, 
	 * So both queues are sync. Let the new request get disk time if

	 * it's a metadata request and the current queue is doing regular IO.

	 */

	if ((rq->cmd_flags & REQ_META) && !cfqq->meta_pending)

	if ((rq->cmd_flags & REQ_PRIO) && !cfqq->prio_pending)

		return true;



	/*
@@ -3439,8 +3439,8 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, 
	struct cfq_io_context *cic = RQ_CIC(rq);



	cfqd->rq_queued++;

	if (rq->cmd_flags & REQ_META)

		cfqq->meta_pending++;

	if (rq->cmd_flags & REQ_PRIO)

		cfqq->prio_pending++;



	cfq_update_io_thinktime(cfqd, cfqq, cic);

	cfq_update_io_seektime(cfqd, cfqq, rq);

drivers/mmc/card/block.c

+3 −0
Original line number Diff line number Diff line
@@ -926,6 +926,9 @@ static void mmc_blk_rw_rq_prep(struct mmc_queue_req *mqrq, 
	/*

	 * Reliable writes are used to implement Forced Unit Access and

	 * REQ_META accesses, and are supported only on MMCs.

	 *

	 * XXX: this really needs a good explanation of why REQ_META

	 * is treated special.

	 */

	bool do_rel_wr = ((req->cmd_flags & REQ_FUA) ||

			  (req->cmd_flags & REQ_META)) &&

fs/ext3/inode.c

+2 −2
Original line number Diff line number Diff line
@@ -1134,7 +1134,7 @@ struct buffer_head *ext3_bread(handle_t *handle, struct inode *inode, 
		return bh;

	if (buffer_uptodate(bh))

		return bh;

	ll_rw_block(READ | REQ_META, 1, &bh);

	ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &bh);

	wait_on_buffer(bh);

	if (buffer_uptodate(bh))

		return bh;
@@ -2807,7 +2807,7 @@ make_io: 
		trace_ext3_load_inode(inode);

		get_bh(bh);

		bh->b_end_io = end_buffer_read_sync;

		submit_bh(READ | REQ_META, bh);

		submit_bh(READ | REQ_META | REQ_PRIO, bh);

		wait_on_buffer(bh);

		if (!buffer_uptodate(bh)) {

			ext3_error(inode->i_sb, "ext3_get_inode_loc",

fs/ext3/namei.c

+2 −1
Original line number Diff line number Diff line
@@ -922,7 +922,8 @@ restart: 
				bh = ext3_getblk(NULL, dir, b++, 0, &err);

				bh_use[ra_max] = bh;

				if (bh)

					ll_rw_block(READ | REQ_META, 1, &bh);

					ll_rw_block(READ | REQ_META | REQ_PRIO,

						    1, &bh);

			}

		}

		if ((bh = bh_use[ra_ptr++]) == NULL)

fs/ext4/inode.c

+2 −2
Original line number Diff line number Diff line
@@ -650,7 +650,7 @@ struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode, 
		return bh;

	if (buffer_uptodate(bh))

		return bh;

	ll_rw_block(READ | REQ_META, 1, &bh);

	ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &bh);

	wait_on_buffer(bh);

	if (buffer_uptodate(bh))

		return bh;
@@ -3301,7 +3301,7 @@ make_io: 
		trace_ext4_load_inode(inode);

		get_bh(bh);

		bh->b_end_io = end_buffer_read_sync;

		submit_bh(READ | REQ_META, bh);

		submit_bh(READ | REQ_META | REQ_PRIO, bh);

		wait_on_buffer(bh);

		if (!buffer_uptodate(bh)) {

			EXT4_ERROR_INODE_BLOCK(inode, block,

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