Messages in this thread | | | From | Song Liu <> | Date | Fri, 15 Dec 2023 01:08:06 -0800 | Subject | Re: [PATCH v2 2/2] md: don't account sync_io if iostats of the disk is disabled |
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On Thu, Dec 14, 2023 at 5:41 PM <linan666@huaweicloud.com> wrote: > > From: Li Nan <linan122@huawei.com> > > 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 <linan122@huawei.com> > --- > 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()?
> } > > 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
> + > curr_events = > (long long)part_stat_read_accum(disk->part0, sectors) - > atomic64_read(&disk->sync_io); > -- > 2.39.2 >
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