diff options
| author | Yu Kuai <yukuai3@huawei.com> | 2024-05-09 20:37:17 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2024-05-09 07:59:44 -0600 |
| commit | 7be835694daebbb4adffbc461519081aa0cf28e1 (patch) | |
| tree | 4f9903b5a99814958e317bf070d77a3d08da902f /block/genhd.c | |
| parent | 99dc422335d8b2bd4d105797241d3e715bae90e9 (diff) | |
block: fix that util can be greater than 100%
util means the percentage that disk has IO, and theoretically it should
not be greater than 100%. However, there is a gap for rq-based disk:
io_ticks will be updated when rq is allocated, however, before such rq
dispatch to driver, it will not be account as inflight from
blk_mq_start_request() hence diskstats_show()/part_stat_show() will not
update io_ticks. For example:
1) at t0, issue a new IO, rq is allocated, and blk_account_io_start()
update io_ticks;
2) something is wrong with drivers, and the rq can't be dispatched;
3) at t0 + 10s, drivers recovers and rq is dispatched and done, io_ticks
is updated;
Then if user is using "iostat 1" to monitor "util", between t0 - t0+9s,
util will be zero, and between t0+9s - t0+10s, util will be 1000%.
Fix this problem by updating io_ticks from diskstats_show() and
part_stat_show() if there are rq allocated.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20240509123717.3223892-3-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/genhd.c')
| -rw-r--r-- | block/genhd.c | 12 |
1 files changed, 2 insertions, 10 deletions
diff --git a/block/genhd.c b/block/genhd.c index 8f1163d2d171..7f39fbe60753 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -951,15 +951,10 @@ ssize_t part_stat_show(struct device *dev, struct device_attribute *attr, char *buf) { struct block_device *bdev = dev_to_bdev(dev); - struct request_queue *q = bdev_get_queue(bdev); struct disk_stats stat; unsigned int inflight; - if (queue_is_mq(q)) - inflight = blk_mq_in_flight(q, bdev); - else - inflight = part_in_flight(bdev); - + inflight = part_in_flight(bdev); if (inflight) { part_stat_lock(); update_io_ticks(bdev, jiffies, true); @@ -1256,11 +1251,8 @@ static int diskstats_show(struct seq_file *seqf, void *v) xa_for_each(&gp->part_tbl, idx, hd) { if (bdev_is_partition(hd) && !bdev_nr_sectors(hd)) continue; - if (queue_is_mq(gp->queue)) - inflight = blk_mq_in_flight(gp->queue, hd); - else - inflight = part_in_flight(hd); + inflight = part_in_flight(hd); if (inflight) { part_stat_lock(); update_io_ticks(hd, jiffies, true); |