在 2023/12/15 17:08, Song Liu 写道:

On Thu, Dec 14, 2023 at 5:41 PM [off-list ref] wrote:

quoted

From: Li Nan <redacted>

If iostats is disabled, disk_stats will not be updated and
part_stat_read_accum() only returns a constant value. In this case,
continuing to count sync_io and to check is_mddev_idle() is no longer
meaningful.

Signed-off-by: Li Nan <redacted>
---
  drivers/md/md.h | 3 ++-
  drivers/md/md.c | 4 ++++
  2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/md/md.h b/drivers/md/md.h
index 1a4f976951c1..75f5c5d04e71 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h

@@ -589,7 +589,8 @@ static inline void md_sync_acct(struct block_device *bdev, unsigned long nr_sect

  static inline void md_sync_acct_bio(struct bio *bio, unsigned long nr_sectors)
  {
-       md_sync_acct(bio->bi_bdev, nr_sectors);
+       if (blk_queue_io_stat(bio->bi_bdev->bd_disk->queue))
+               md_sync_acct(bio->bi_bdev, nr_sectors);

Do we need the same check for md_sync_acct()?

quoted

  }

  struct md_personality

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 1d71b2a9af03..18bbceb0ffd6 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c

@@ -8502,6 +8502,10 @@ static int is_mddev_idle(struct mddev *mddev, int init)
         rcu_read_lock();
         rdev_for_each_rcu(rdev, mddev) {
                 struct gendisk *disk = rdev->bdev->bd_disk;
+
+               if (blk_queue_io_stat(mddev->queue))
+                       continue;

This looks weird. Do you mean

    if (!blk_queue_io_stat(disk->queue))

Note that I changed two things here: 1) add "!"; 2) check disk, not mddev.

Did I miss something?

Thanks,
Song

Yeah... It's my bad. I will fix it in v3.

quoted

+
                 curr_events =
                         (long long)part_stat_read_accum(disk->part0, sectors) -
                               atomic64_read(&disk->sync_io);
--
2.39.2

.

-- 
Thanks,
Nan