Messages in this thread | | | Date | Sat, 19 Feb 2022 11:02:36 +0800 | Subject | Re: [PATCH -next v2] block: update io_ticks when io hang | From | "zhangwensheng (E)" <> |
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friendly ping...
在 2022/2/17 14:42, Zhang Wensheng 写道: > 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> > --- > block/genhd.c | 14 ++++++++++++-- > 1 file changed, 12 insertions(+), 2 deletions(-) > --- > v2: > * add part_stat_lock() & part_stat_unlock() to protect update_io_ticks(). > v1: https://www.spinics.net/lists/linux-block/msg78931.html > > diff --git a/block/genhd.c b/block/genhd.c > index 626c8406f21a..781dc78f97d8 100644 > --- a/block/genhd.c > +++ b/block/genhd.c > @@ -913,12 +913,17 @@ 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 " > @@ -1174,12 +1179,17 @@ 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 "
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