Commit ea3d1f10 authored by Yu Kuai's avatar Yu Kuai Committed by Jens Axboe
Browse files

blk-mq: add QUEUE_FLAG_BIO_ISSUE_TIME 



bio->issue_time_ns is initialized for every bio, however, it's only used
by blk-iolatency. Add a new queue_flag and only set this flag when
blk-iolatency is enabled, so that extra blk_time_get_ns() can be saved
for disks that blk-iolatency is not enabled.

Signed-off-by: default avatarYu Kuai <yukuai3@huawei.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 1f963bdd

block/blk-iolatency.c

+5 −0
Original line number Diff line number Diff line
@@ -742,10 +742,15 @@ static void blkiolatency_enable_work_fn(struct work_struct *work) 
	 */

	enabled = atomic_read(&blkiolat->enable_cnt);

	if (enabled != blkiolat->enabled) {

		struct request_queue *q = blkiolat->rqos.disk->queue;

		unsigned int memflags;



		memflags = blk_mq_freeze_queue(blkiolat->rqos.disk->queue);

		blkiolat->enabled = enabled;

		if (enabled)

			blk_queue_flag_set(QUEUE_FLAG_BIO_ISSUE_TIME, q);

		else

			blk_queue_flag_clear(QUEUE_FLAG_BIO_ISSUE_TIME, q);

		blk_mq_unfreeze_queue(blkiolat->rqos.disk->queue, memflags);

	}

}

block/blk-mq-debugfs.c

+1 −0
Original line number Diff line number Diff line
@@ -96,6 +96,7 @@ static const char *const blk_queue_flag_name[] = { 
	QUEUE_FLAG_NAME(DISABLE_WBT_DEF),

	QUEUE_FLAG_NAME(NO_ELV_SWITCH),

	QUEUE_FLAG_NAME(QOS_ENABLED),

	QUEUE_FLAG_NAME(BIO_ISSUE_TIME),

};

#undef QUEUE_FLAG_NAME

block/blk-mq.c

+5 −3
Original line number Diff line number Diff line
@@ -396,9 +396,11 @@ static inline void blk_mq_rq_time_init(struct request *rq, u64 alloc_time_ns) 
#endif

}



static inline void blk_mq_bio_issue_init(struct bio *bio)

static inline void blk_mq_bio_issue_init(struct request_queue *q,

					 struct bio *bio)

{

#ifdef CONFIG_BLK_CGROUP

	if (test_bit(QUEUE_FLAG_BIO_ISSUE_TIME, &q->queue_flags))

		bio->issue_time_ns = blk_time_get_ns();

#endif

}
@@ -3175,7 +3177,7 @@ void blk_mq_submit_bio(struct bio *bio) 
	if (!bio_integrity_prep(bio))

		goto queue_exit;



	blk_mq_bio_issue_init(bio);

	blk_mq_bio_issue_init(q, bio);

	if (blk_mq_attempt_bio_merge(q, bio, nr_segs))

		goto queue_exit;

include/linux/blkdev.h

+1 −0
Original line number Diff line number Diff line
@@ -657,6 +657,7 @@ enum { 
	QUEUE_FLAG_DISABLE_WBT_DEF,	/* for sched to disable/enable wbt */

	QUEUE_FLAG_NO_ELV_SWITCH,	/* can't switch elevator any more */

	QUEUE_FLAG_QOS_ENABLED,		/* qos is enabled */

	QUEUE_FLAG_BIO_ISSUE_TIME,	/* record bio->issue_time_ns */

	QUEUE_FLAG_MAX

};