diff options
| author | Shaohua Li <shli@fb.com> | 2017-02-11 03:18:09 +0300 |
|---|---|---|
| committer | Shaohua Li <shli@fb.com> | 2017-02-13 20:20:05 +0300 |
| commit | e33fbb9cc73d6502e69eaf1c178e0c39059763ea (patch) | |
| tree | 3a75c9e524eab2facb854a41e970dfb86fc538c1 /drivers/md/raid5-cache.c | |
| parent | e8fd52eec2cd25b917983b3f3aa738b722522376 (diff) | |
| download | linux-e33fbb9cc73d6502e69eaf1c178e0c39059763ea.tar.xz | |
md/raid5-cache: exclude reclaiming stripes in reclaim check
stripes which are being reclaimed are still accounted into cached
stripes. The reclaim takes time. r5c_do_reclaim isn't aware of the
stripes and does unnecessary stripe reclaim. In practice, I saw one
stripe is reclaimed one time. This will cause bad IO pattern. Fixing
this by excluding the reclaing stripes in the check.
Cc: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Diffstat (limited to 'drivers/md/raid5-cache.c')
| -rw-r--r-- | drivers/md/raid5-cache.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c index a01f4daeb390..3f307be01b10 100644 --- a/drivers/md/raid5-cache.c +++ b/drivers/md/raid5-cache.c @@ -1327,6 +1327,10 @@ static void r5c_flush_stripe(struct r5conf *conf, struct stripe_head *sh) atomic_inc(&conf->active_stripes); r5c_make_stripe_write_out(sh); + if (test_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state)) + atomic_inc(&conf->r5c_flushing_partial_stripes); + else + atomic_inc(&conf->r5c_flushing_full_stripes); raid5_release_stripe(sh); } @@ -1369,12 +1373,16 @@ static void r5c_do_reclaim(struct r5conf *conf) unsigned long flags; int total_cached; int stripes_to_flush; + int flushing_partial, flushing_full; if (!r5c_is_writeback(log)) return; + flushing_partial = atomic_read(&conf->r5c_flushing_partial_stripes); + flushing_full = atomic_read(&conf->r5c_flushing_full_stripes); total_cached = atomic_read(&conf->r5c_cached_partial_stripes) + - atomic_read(&conf->r5c_cached_full_stripes); + atomic_read(&conf->r5c_cached_full_stripes) - + flushing_full - flushing_partial; if (total_cached > conf->min_nr_stripes * 3 / 4 || atomic_read(&conf->empty_inactive_list_nr) > 0) @@ -1384,7 +1392,7 @@ static void r5c_do_reclaim(struct r5conf *conf) */ stripes_to_flush = R5C_RECLAIM_STRIPE_GROUP; else if (total_cached > conf->min_nr_stripes * 1 / 2 || - atomic_read(&conf->r5c_cached_full_stripes) > + atomic_read(&conf->r5c_cached_full_stripes) - flushing_full > R5C_FULL_STRIPE_FLUSH_BATCH) /* * if stripe cache pressure moderate, or if there is many full @@ -2601,11 +2609,13 @@ void r5c_finish_stripe_write_out(struct r5conf *conf, if (test_and_clear_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state)) { BUG_ON(atomic_read(&conf->r5c_cached_partial_stripes) == 0); + atomic_dec(&conf->r5c_flushing_partial_stripes); atomic_dec(&conf->r5c_cached_partial_stripes); } if (test_and_clear_bit(STRIPE_R5C_FULL_STRIPE, &sh->state)) { BUG_ON(atomic_read(&conf->r5c_cached_full_stripes) == 0); + atomic_dec(&conf->r5c_flushing_full_stripes); atomic_dec(&conf->r5c_cached_full_stripes); } } |