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path: root/drivers/md/dm-cache-policy-smq.c
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Diffstat (limited to 'drivers/md/dm-cache-policy-smq.c')
-rw-r--r--drivers/md/dm-cache-policy-smq.c45
1 files changed, 12 insertions, 33 deletions
diff --git a/drivers/md/dm-cache-policy-smq.c b/drivers/md/dm-cache-policy-smq.c
index cf48a617a3a4..c33f4a6e1d7d 100644
--- a/drivers/md/dm-cache-policy-smq.c
+++ b/drivers/md/dm-cache-policy-smq.c
@@ -1359,6 +1359,11 @@ static void smq_clear_dirty(struct dm_cache_policy *p, dm_oblock_t oblock)
spin_unlock_irqrestore(&mq->lock, flags);
}
+static unsigned random_level(dm_cblock_t cblock)
+{
+ return hash_32_generic(from_cblock(cblock), 9) & (NR_CACHE_LEVELS - 1);
+}
+
static int smq_load_mapping(struct dm_cache_policy *p,
dm_oblock_t oblock, dm_cblock_t cblock,
uint32_t hint, bool hint_valid)
@@ -1369,47 +1374,21 @@ static int smq_load_mapping(struct dm_cache_policy *p,
e = alloc_particular_entry(&mq->cache_alloc, from_cblock(cblock));
e->oblock = oblock;
e->dirty = false; /* this gets corrected in a minute */
- e->level = hint_valid ? min(hint, NR_CACHE_LEVELS - 1) : 1;
+ e->level = hint_valid ? min(hint, NR_CACHE_LEVELS - 1) : random_level(cblock);
push(mq, e);
return 0;
}
-static int smq_save_hints(struct smq_policy *mq, struct queue *q,
- policy_walk_fn fn, void *context)
-{
- int r;
- unsigned level;
- struct entry *e;
-
- for (level = 0; level < q->nr_levels; level++)
- for (e = l_head(q->es, q->qs + level); e; e = l_next(q->es, e)) {
- if (!e->sentinel) {
- r = fn(context, infer_cblock(mq, e),
- e->oblock, e->level);
- if (r)
- return r;
- }
- }
-
- return 0;
-}
-
-static int smq_walk_mappings(struct dm_cache_policy *p, policy_walk_fn fn,
- void *context)
+static uint32_t smq_get_hint(struct dm_cache_policy *p, dm_cblock_t cblock)
{
struct smq_policy *mq = to_smq_policy(p);
- int r = 0;
+ struct entry *e = get_entry(&mq->cache_alloc, from_cblock(cblock));
- /*
- * 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);
+ if (!e->allocated)
+ return 0;
- return r;
+ return e->level;
}
static void __remove_mapping(struct smq_policy *mq, dm_oblock_t oblock)
@@ -1616,7 +1595,7 @@ static void init_policy_functions(struct smq_policy *mq, bool mimic_mq)
mq->policy.set_dirty = smq_set_dirty;
mq->policy.clear_dirty = smq_clear_dirty;
mq->policy.load_mapping = smq_load_mapping;
- mq->policy.walk_mappings = smq_walk_mappings;
+ mq->policy.get_hint = smq_get_hint;
mq->policy.remove_mapping = smq_remove_mapping;
mq->policy.remove_cblock = smq_remove_cblock;
mq->policy.writeback_work = smq_writeback_work;