diff options
| -rw-r--r-- | drivers/md/dm-cache-policy-smq.c | 110 |
1 files changed, 39 insertions, 71 deletions
diff --git a/drivers/md/dm-cache-policy-smq.c b/drivers/md/dm-cache-policy-smq.c index 200366c62231..1ffbeb1b3ea6 100644 --- a/drivers/md/dm-cache-policy-smq.c +++ b/drivers/md/dm-cache-policy-smq.c @@ -772,7 +772,7 @@ struct smq_policy { struct dm_cache_policy policy; /* protects everything */ - struct mutex lock; + spinlock_t lock; dm_cblock_t cache_size; sector_t cache_block_size; @@ -807,13 +807,7 @@ struct smq_policy { /* * Keeps track of time, incremented by the core. We use this to * avoid attributing multiple hits within the same tick. - * - * Access to tick_protected should be done with the spin lock held. - * It's copied to tick at the start of the map function (within the - * mutex). */ - spinlock_t tick_lock; - unsigned tick_protected; unsigned tick; /* @@ -1296,46 +1290,20 @@ static void smq_destroy(struct dm_cache_policy *p) kfree(mq); } -static void copy_tick(struct smq_policy *mq) -{ - unsigned long flags, tick; - - spin_lock_irqsave(&mq->tick_lock, flags); - tick = mq->tick_protected; - if (tick != mq->tick) { - update_sentinels(mq); - end_hotspot_period(mq); - end_cache_period(mq); - mq->tick = tick; - } - spin_unlock_irqrestore(&mq->tick_lock, flags); -} - -static bool maybe_lock(struct smq_policy *mq, bool can_block) -{ - if (can_block) { - mutex_lock(&mq->lock); - return true; - } else - return mutex_trylock(&mq->lock); -} - static int smq_map(struct dm_cache_policy *p, dm_oblock_t oblock, bool can_block, bool can_migrate, bool fast_promote, struct bio *bio, struct policy_locker *locker, struct policy_result *result) { int r; + unsigned long flags; struct smq_policy *mq = to_smq_policy(p); result->op = POLICY_MISS; - if (!maybe_lock(mq, can_block)) - return -EWOULDBLOCK; - - copy_tick(mq); + spin_lock_irqsave(&mq->lock, flags); r = map(mq, bio, oblock, can_migrate, fast_promote, locker, result); - mutex_unlock(&mq->lock); + spin_unlock_irqrestore(&mq->lock, flags); return r; } @@ -1343,20 +1311,18 @@ static int smq_map(struct dm_cache_policy *p, dm_oblock_t oblock, static int smq_lookup(struct dm_cache_policy *p, dm_oblock_t oblock, dm_cblock_t *cblock) { int r; + unsigned long flags; struct smq_policy *mq = to_smq_policy(p); struct entry *e; - if (!mutex_trylock(&mq->lock)) - return -EWOULDBLOCK; - + spin_lock_irqsave(&mq->lock, flags); e = h_lookup(&mq->table, oblock); if (e) { *cblock = infer_cblock(mq, e); r = 0; } else r = -ENOENT; - - mutex_unlock(&mq->lock); + spin_unlock_irqrestore(&mq->lock, flags); return r; } @@ -1375,20 +1341,22 @@ static void __smq_set_clear_dirty(struct smq_policy *mq, dm_oblock_t oblock, boo static void smq_set_dirty(struct dm_cache_policy *p, dm_oblock_t oblock) { + unsigned long flags; struct smq_policy *mq = to_smq_policy(p); - mutex_lock(&mq->lock); + spin_lock_irqsave(&mq->lock, flags); __smq_set_clear_dirty(mq, oblock, true); - mutex_unlock(&mq->lock); + spin_unlock_irqrestore(&mq->lock, flags); } static void smq_clear_dirty(struct dm_cache_policy *p, dm_oblock_t oblock) { struct smq_policy *mq = to_smq_policy(p); + unsigned long flags; - mutex_lock(&mq->lock); + spin_lock_irqsave(&mq->lock, flags); __smq_set_clear_dirty(mq, oblock, false); - mutex_unlock(&mq->lock); + spin_unlock_irqrestore(&mq->lock, flags); } static int smq_load_mapping(struct dm_cache_policy *p, @@ -1433,14 +1401,14 @@ static int smq_walk_mappings(struct dm_cache_policy *p, policy_walk_fn fn, struct smq_policy *mq = to_smq_policy(p); int r = 0; - mutex_lock(&mq->lock); - + /* + * We don't need to lock here since this method is only called once + * the IO has stopped. + */ r = smq_save_hints(mq, &mq->clean, fn, context); if (!r) r = smq_save_hints(mq, &mq->dirty, fn, context); - mutex_unlock(&mq->lock); - return r; } @@ -1458,10 +1426,11 @@ static void __remove_mapping(struct smq_policy *mq, dm_oblock_t oblock) static void smq_remove_mapping(struct dm_cache_policy *p, dm_oblock_t oblock) { struct smq_policy *mq = to_smq_policy(p); + unsigned long flags; - mutex_lock(&mq->lock); + spin_lock_irqsave(&mq->lock, flags); __remove_mapping(mq, oblock); - mutex_unlock(&mq->lock); + spin_unlock_irqrestore(&mq->lock, flags); } static int __remove_cblock(struct smq_policy *mq, dm_cblock_t cblock) @@ -1480,11 +1449,12 @@ static int __remove_cblock(struct smq_policy *mq, dm_cblock_t cblock) static int smq_remove_cblock(struct dm_cache_policy *p, dm_cblock_t cblock) { int r; + unsigned long flags; struct smq_policy *mq = to_smq_policy(p); - mutex_lock(&mq->lock); + spin_lock_irqsave(&mq->lock, flags); r = __remove_cblock(mq, cblock); - mutex_unlock(&mq->lock); + spin_unlock_irqrestore(&mq->lock, flags); return r; } @@ -1537,11 +1507,12 @@ static int smq_writeback_work(struct dm_cache_policy *p, dm_oblock_t *oblock, dm_cblock_t *cblock, bool critical_only) { int r; + unsigned long flags; struct smq_policy *mq = to_smq_policy(p); - mutex_lock(&mq->lock); + spin_lock_irqsave(&mq->lock, flags); r = __smq_writeback_work(mq, oblock, cblock, critical_only); - mutex_unlock(&mq->lock); + spin_unlock_irqrestore(&mq->lock, flags); return r; } @@ -1562,21 +1533,23 @@ static void __force_mapping(struct smq_policy *mq, static void smq_force_mapping(struct dm_cache_policy *p, dm_oblock_t current_oblock, dm_oblock_t new_oblock) { + unsigned long flags; struct smq_policy *mq = to_smq_policy(p); - mutex_lock(&mq->lock); + spin_lock_irqsave(&mq->lock, flags); __force_mapping(mq, current_oblock, new_oblock); - mutex_unlock(&mq->lock); + spin_unlock_irqrestore(&mq->lock, flags); } static dm_cblock_t smq_residency(struct dm_cache_policy *p) { dm_cblock_t r; + unsigned long flags; struct smq_policy *mq = to_smq_policy(p); - mutex_lock(&mq->lock); + spin_lock_irqsave(&mq->lock, flags); r = to_cblock(mq->cache_alloc.nr_allocated); - mutex_unlock(&mq->lock); + spin_unlock_irqrestore(&mq->lock, flags); return r; } @@ -1586,15 +1559,12 @@ static void smq_tick(struct dm_cache_policy *p, bool can_block) struct smq_policy *mq = to_smq_policy(p); unsigned long flags; - spin_lock_irqsave(&mq->tick_lock, flags); - mq->tick_protected++; - spin_unlock_irqrestore(&mq->tick_lock, flags); - - if (can_block) { - mutex_lock(&mq->lock); - copy_tick(mq); - mutex_unlock(&mq->lock); - } + spin_lock_irqsave(&mq->lock, flags); + mq->tick++; + update_sentinels(mq); + end_hotspot_period(mq); + end_cache_period(mq); + spin_unlock_irqrestore(&mq->lock, flags); } /* Init the policy plugin interface function pointers. */ @@ -1694,10 +1664,8 @@ static struct dm_cache_policy *smq_create(dm_cblock_t cache_size, } else mq->cache_hit_bits = NULL; - mq->tick_protected = 0; mq->tick = 0; - mutex_init(&mq->lock); - spin_lock_init(&mq->tick_lock); + spin_lock_init(&mq->lock); q_init(&mq->hotspot, &mq->es, NR_HOTSPOT_LEVELS); mq->hotspot.nr_top_levels = 8; |