Commit d72d904a authored by Jens Axboe's avatar Jens Axboe
Browse files

[BLOCK] Update read/write block io statistics at completion time 



Right now we do it at queueing time, which works alright for reads
(since they are usually sync), but not for async writes since we can
queue io a lot faster than we can complete it. This makes the vmstat
output look extremely bursty.

Signed-off-by: default avatarJens Axboe <axboe@suse.de>
parent d83c671f

drivers/block/ll_rw_blk.c

+11 −8
Original line number Diff line number Diff line
@@ -2387,16 +2387,12 @@ static void drive_stat_acct(struct request *rq, int nr_sectors, int new_io) 
	if (!blk_fs_request(rq) || !rq->rq_disk)

		return;



	if (rw == READ) {

		__disk_stat_add(rq->rq_disk, read_sectors, nr_sectors);

		if (!new_io)

	if (!new_io) {

		if (rw == READ)

			__disk_stat_inc(rq->rq_disk, read_merges);

	} else if (rw == WRITE) {

		__disk_stat_add(rq->rq_disk, write_sectors, nr_sectors);

		if (!new_io)

		else

			__disk_stat_inc(rq->rq_disk, write_merges);

	}

	if (new_io) {

	} else {

		disk_round_stats(rq->rq_disk);

		rq->rq_disk->in_flight++;

	}
@@ -3048,6 +3044,13 @@ static int __end_that_request_first(struct request *req, int uptodate, 
				(unsigned long long)req->sector);

	}



	if (blk_fs_request(req) && req->rq_disk) {

		if (rq_data_dir(req) == READ)

			__disk_stat_add(req->rq_disk, read_sectors, nr_bytes >> 9);

		else

			__disk_stat_add(req->rq_disk, write_sectors, nr_bytes >> 9);

	}



	total_bytes = bio_nbytes = 0;

	while ((bio = req->bio) != NULL) {

		int nbytes;