diff options
| author | Xiao Ni <xni@redhat.com> | 2017-04-27 16:28:49 +0800 |
|---|---|---|
| committer | Shaohua Li <shli@fb.com> | 2017-04-27 14:01:16 -0700 |
| commit | 43ac9b84a399bc10210a2d9f4e0778b7c6059c07 (patch) | |
| tree | fed7746123467e4c61fe7ce792aa888a0252f1d3 /drivers/md/raid1.h | |
| parent | e5bc9c3c5432f5531a58e6fdd9f6c6587f2137b3 (diff) | |
md/raid1: Use a new variable to count flighting sync requests
In new barrier codes, raise_barrier waits if conf->nr_pending[idx] is not zero.
After all the conditions are true, the resync request can go on be handled. But
it adds conf->nr_pending[idx] again. The next resync request hit the same bucket
idx need to wait the resync request which is submitted before. The performance
of resync/recovery is degraded.
So we should use a new variable to count sync requests which are in flight.
I did a simple test:
1. Without the patch, create a raid1 with two disks. The resync speed:
Device: rrqm/s wrqm/s r/s w/s rMB/s wMB/s avgrq-sz avgqu-sz await r_await w_await svctm %util
sdb 0.00 0.00 166.00 0.00 10.38 0.00 128.00 0.03 0.20 0.20 0.00 0.19 3.20
sdc 0.00 0.00 0.00 166.00 0.00 10.38 128.00 0.96 5.77 0.00 5.77 5.75 95.50
2. With the patch, the result is:
sdb 2214.00 0.00 766.00 0.00 185.69 0.00 496.46 2.80 3.66 3.66 0.00 1.03 79.10
sdc 0.00 2205.00 0.00 769.00 0.00 186.44 496.52 5.25 6.84 0.00 6.84 1.30 100.10
Suggested-by: Shaohua Li <shli@kernel.org>
Signed-off-by: Xiao Ni <xni@redhat.com>
Acked-by: Coly Li <colyli@suse.de>
Signed-off-by: Shaohua Li <shli@fb.com>
Diffstat (limited to 'drivers/md/raid1.h')
| -rw-r--r-- | drivers/md/raid1.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/md/raid1.h b/drivers/md/raid1.h index b0ab0da6e39e..c8894ef1e9d2 100644 --- a/drivers/md/raid1.h +++ b/drivers/md/raid1.h @@ -84,6 +84,7 @@ struct r1conf { */ wait_queue_head_t wait_barrier; spinlock_t resync_lock; + atomic_t nr_sync_pending; atomic_t *nr_pending; atomic_t *nr_waiting; atomic_t *nr_queued; |