[dm-devel] [PATCH 2/2 v2] dm thin: use slab mempools with local caches
Mike Snitzer
snitzer at redhat.com
Thu Apr 12 22:39:17 UTC 2012
Use dedicated caches prefixed with a "dm_" name rather than rely on
kmalloc mempools backed by generic slab caches.
This will aid in debugging thinp memory leaks should they occur.
Signed-off-by: Mike Snitzer <snitzer at redhat.com>
---
drivers/md/dm-thin.c | 52 +++++++++++++++++++++++++++++++++++++++++++++----
1 files changed, 47 insertions(+), 5 deletions(-)
v2: tweaked subject and header some, no code changes.
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index 301db0f..57d40b1 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -141,6 +141,8 @@ static uint32_t calc_nr_buckets(unsigned nr_cells)
return n;
}
+struct kmem_cache *_cell_cache;
+
/*
* @nr_cells should be the number of cells you want in use _concurrently_.
* Don't confuse it with the number of distinct keys.
@@ -157,8 +159,7 @@ static struct bio_prison *prison_create(unsigned nr_cells)
return NULL;
spin_lock_init(&prison->lock);
- prison->cell_pool = mempool_create_kmalloc_pool(nr_cells,
- sizeof(struct cell));
+ prison->cell_pool = mempool_create_slab_pool(nr_cells, _cell_cache);
if (!prison->cell_pool) {
kfree(prison);
return NULL;
@@ -1649,6 +1650,9 @@ static void pool_features_init(struct pool_features *pf)
pf->discard_passdown = 1;
}
+struct kmem_cache *_new_mapping_cache;
+struct kmem_cache *_endio_hook_cache;
+
static void __pool_destroy(struct pool *pool)
{
__pool_table_remove(pool);
@@ -1738,7 +1742,7 @@ static struct pool *pool_create(struct mapped_device *pool_md,
pool->next_mapping = NULL;
pool->mapping_pool =
- mempool_create_kmalloc_pool(MAPPING_POOL_SIZE, sizeof(struct new_mapping));
+ mempool_create_slab_pool(MAPPING_POOL_SIZE, _new_mapping_cache);
if (!pool->mapping_pool) {
*error = "Error creating pool's mapping mempool";
err_p = ERR_PTR(-ENOMEM);
@@ -1746,7 +1750,7 @@ static struct pool *pool_create(struct mapped_device *pool_md,
}
pool->endio_hook_pool =
- mempool_create_kmalloc_pool(ENDIO_HOOK_POOL_SIZE, sizeof(struct endio_hook));
+ mempool_create_slab_pool(ENDIO_HOOK_POOL_SIZE, _endio_hook_cache);
if (!pool->endio_hook_pool) {
*error = "Error creating pool's endio_hook mempool";
err_p = ERR_PTR(-ENOMEM);
@@ -2748,7 +2752,42 @@ static int __init dm_thin_init(void)
r = dm_register_target(&pool_target);
if (r)
- dm_unregister_target(&thin_target);
+ goto bad_pool_target;
+
+ _cell_cache = kmem_cache_create("dm_bio_prison_cell",
+ sizeof(struct cell),
+ __alignof__(struct cell), 0, NULL);
+ if (!_cell_cache) {
+ r = -ENOMEM;
+ goto bad_cell_cache;
+ }
+
+ _new_mapping_cache = kmem_cache_create("dm_thin_new_mapping",
+ sizeof(struct new_mapping),
+ __alignof__(struct new_mapping), 0, NULL);
+ if (!_new_mapping_cache) {
+ r = -ENOMEM;
+ goto bad_new_mapping_cache;
+ }
+
+ _endio_hook_cache = kmem_cache_create("dm_thin_endio_hook",
+ sizeof(struct endio_hook),
+ __alignof__(struct endio_hook), 0, NULL);
+ if (!_endio_hook_cache) {
+ r = -ENOMEM;
+ goto bad_endio_hook_cache;
+ }
+
+ return 0;
+
+bad_endio_hook_cache:
+ kmem_cache_destroy(_new_mapping_cache);
+bad_new_mapping_cache:
+ kmem_cache_destroy(_cell_cache);
+bad_cell_cache:
+ dm_unregister_target(&pool_target);
+bad_pool_target:
+ dm_unregister_target(&thin_target);
return r;
}
@@ -2757,6 +2796,9 @@ static void dm_thin_exit(void)
{
dm_unregister_target(&thin_target);
dm_unregister_target(&pool_target);
+ kmem_cache_destroy(_cell_cache);
+ kmem_cache_destroy(_new_mapping_cache);
+ kmem_cache_destroy(_endio_hook_cache);
}
module_init(dm_thin_init);
--
1.7.4.4
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