diff options
| -rw-r--r-- | drivers/md/dm-bufio.c | 60 |
1 files changed, 41 insertions, 19 deletions
diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c index 6d1565021d74..9c1a86bde658 100644 --- a/drivers/md/dm-bufio.c +++ b/drivers/md/dm-bufio.c @@ -108,7 +108,10 @@ struct dm_bufio_client { int async_write_error; struct list_head client_list; + struct shrinker shrinker; + struct work_struct shrink_work; + atomic_long_t need_shrink; }; /* @@ -1634,8 +1637,7 @@ static unsigned long get_retain_buffers(struct dm_bufio_client *c) return retain_bytes; } -static unsigned long __scan(struct dm_bufio_client *c, unsigned long nr_to_scan, - gfp_t gfp_mask) +static void __scan(struct dm_bufio_client *c) { int l; struct dm_buffer *b, *tmp; @@ -1646,42 +1648,58 @@ static unsigned long __scan(struct dm_bufio_client *c, unsigned long nr_to_scan, for (l = 0; l < LIST_SIZE; l++) { list_for_each_entry_safe_reverse(b, tmp, &c->lru[l], lru_list) { - if (__try_evict_buffer(b, gfp_mask)) + if (count - freed <= retain_target) + atomic_long_set(&c->need_shrink, 0); + if (!atomic_long_read(&c->need_shrink)) + return; + if (__try_evict_buffer(b, GFP_KERNEL)) { + atomic_long_dec(&c->need_shrink); freed++; - if (!--nr_to_scan || ((count - freed) <= retain_target)) - return freed; + } cond_resched(); } } - return freed; } -static unsigned long -dm_bufio_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) +static void shrink_work(struct work_struct *w) +{ + struct dm_bufio_client *c = container_of(w, struct dm_bufio_client, shrink_work); + + dm_bufio_lock(c); + __scan(c); + dm_bufio_unlock(c); +} + +static unsigned long dm_bufio_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) { struct dm_bufio_client *c; - unsigned long freed; c = container_of(shrink, struct dm_bufio_client, shrinker); - if (sc->gfp_mask & __GFP_FS) - dm_bufio_lock(c); - else if (!dm_bufio_trylock(c)) - return SHRINK_STOP; + atomic_long_add(sc->nr_to_scan, &c->need_shrink); + queue_work(dm_bufio_wq, &c->shrink_work); - freed = __scan(c, sc->nr_to_scan, sc->gfp_mask); - dm_bufio_unlock(c); - return freed; + return sc->nr_to_scan; } -static unsigned long -dm_bufio_shrink_count(struct shrinker *shrink, struct shrink_control *sc) +static unsigned long dm_bufio_shrink_count(struct shrinker *shrink, struct shrink_control *sc) { struct dm_bufio_client *c = container_of(shrink, struct dm_bufio_client, shrinker); unsigned long count = READ_ONCE(c->n_buffers[LIST_CLEAN]) + READ_ONCE(c->n_buffers[LIST_DIRTY]); unsigned long retain_target = get_retain_buffers(c); + unsigned long queued_for_cleanup = atomic_long_read(&c->need_shrink); + + if (unlikely(count < retain_target)) + count = 0; + else + count -= retain_target; - return (count < retain_target) ? 0 : (count - retain_target); + if (unlikely(count < queued_for_cleanup)) + count = 0; + else + count -= queued_for_cleanup; + + return count; } /* @@ -1772,6 +1790,9 @@ struct dm_bufio_client *dm_bufio_client_create(struct block_device *bdev, unsign __free_buffer_wake(b); } + INIT_WORK(&c->shrink_work, shrink_work); + atomic_long_set(&c->need_shrink, 0); + c->shrinker.count_objects = dm_bufio_shrink_count; c->shrinker.scan_objects = dm_bufio_shrink_scan; c->shrinker.seeks = 1; @@ -1817,6 +1838,7 @@ void dm_bufio_client_destroy(struct dm_bufio_client *c) drop_buffers(c); unregister_shrinker(&c->shrinker); + flush_work(&c->shrink_work); mutex_lock(&dm_bufio_clients_lock); |