From: Zhang Wensheng zhangwensheng5@huawei.com
[ Upstream commit 86d7331299fda7634b11c1b7c911432679d525a5 ]
When the inflight IOs are slow and no new IOs are issued, we expect iostat could manifest the IO hang problem. However after commit 5b18b5a73760 ("block: delete part_round_stats and switch to less precise counting"), io_tick and time_in_queue will not be updated until the end of IO, and the avgqu-sz and %util columns of iostat will be zero.
Because it has using stat.nsecs accumulation to express time_in_queue which is not suitable to change, and may %util will express the status better when io hang occur. To fix io_ticks, we use update_io_ticks and inflight to update io_ticks when diskstats_show and part_stat_show been called.
Fixes: 5b18b5a73760 ("block: delete part_round_stats and switch to less precise counting") Signed-off-by: Zhang Wensheng zhangwensheng5@huawei.com Reviewed-by: Christoph Hellwig hch@lst.de Link: https://lore.kernel.org/r/20220217064247.4041435-1-zhangwensheng5@huawei.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- block/genhd.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/block/genhd.c b/block/genhd.c index 9eca1f7d35c9..6fa8b2068cc2 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -927,12 +927,17 @@ ssize_t part_stat_show(struct device *dev, struct disk_stats stat; unsigned int inflight;
- part_stat_read_all(bdev, &stat); if (queue_is_mq(q)) inflight = blk_mq_in_flight(q, bdev); else inflight = part_in_flight(bdev);
+ if (inflight) { + part_stat_lock(); + update_io_ticks(bdev, jiffies, true); + part_stat_unlock(); + } + part_stat_read_all(bdev, &stat); return sprintf(buf, "%8lu %8lu %8llu %8u " "%8lu %8lu %8llu %8u " @@ -1188,12 +1193,17 @@ 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; - part_stat_read_all(hd, &stat); if (queue_is_mq(gp->queue)) inflight = blk_mq_in_flight(gp->queue, hd); else inflight = part_in_flight(hd);
+ if (inflight) { + part_stat_lock(); + update_io_ticks(hd, jiffies, true); + part_stat_unlock(); + } + part_stat_read_all(hd, &stat); seq_printf(seqf, "%4d %7d %pg " "%lu %lu %lu %u " "%lu %lu %lu %u "