1 files changed, 20 insertions, 41 deletions

diff --git a/mm/zswap.c b/mm/zswap.c
index a546c01602aa..66decab33d14 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -124,9 +124,6 @@ static unsigned int zswap_accept_thr_percent = 90; /* of max pool size */
 module_param_named(accept_threshold_percent, zswap_accept_thr_percent,
 		   uint, 0644);
 
-/* Number of zpools in zswap_pool (empirically determined for scalability) */
-#define ZSWAP_NR_ZPOOLS 32
-
 /* Enable/disable memory pressure-based shrinker. */
 static bool zswap_shrinker_enabled = IS_ENABLED(
 		CONFIG_ZSWAP_SHRINKER_DEFAULT_ON);
@@ -162,7 +159,7 @@ struct crypto_acomp_ctx {
  * needs to be verified that it's still valid in the tree.
  */
 struct zswap_pool {
-	struct zpool *zpools[ZSWAP_NR_ZPOOLS];
+	struct zpool *zpool;
 	struct crypto_acomp_ctx __percpu *acomp_ctx;
 	struct percpu_ref ref;
 	struct list_head list;
@@ -244,7 +241,7 @@ static inline struct xarray *swap_zswap_tree(swp_entry_t swp)
 
 #define zswap_pool_debug(msg, p)				\
 	pr_debug("%s pool %s/%s\n", msg, (p)->tfm_name,		\
-		 zpool_get_type((p)->zpools[0]))
+		 zpool_get_type((p)->zpool))
 
 /*********************************
 * pool functions
@@ -253,7 +250,6 @@ static void __zswap_pool_empty(struct percpu_ref *ref);
 
 static struct zswap_pool *zswap_pool_create(char *type, char *compressor)
 {
-	int i;
 	struct zswap_pool *pool;
 	char name[38]; /* 'zswap' + 32 char (max) num + \0 */
 	gfp_t gfp = __GFP_NORETRY | __GFP_NOWARN | __GFP_KSWAPD_RECLAIM;
@@ -274,18 +270,14 @@ static struct zswap_pool *zswap_pool_create(char *type, char *compressor)
 	if (!pool)
 		return NULL;
 
-	for (i = 0; i < ZSWAP_NR_ZPOOLS; i++) {
-		/* unique name for each pool specifically required by zsmalloc */
-		snprintf(name, 38, "zswap%x",
-			 atomic_inc_return(&zswap_pools_count));
-
-		pool->zpools[i] = zpool_create_pool(type, name, gfp);
-		if (!pool->zpools[i]) {
-			pr_err("%s zpool not available\n", type);
-			goto error;
-		}
+	/* unique name for each pool specifically required by zsmalloc */
+	snprintf(name, 38, "zswap%x", atomic_inc_return(&zswap_pools_count));
+	pool->zpool = zpool_create_pool(type, name, gfp);
+	if (!pool->zpool) {
+		pr_err("%s zpool not available\n", type);
+		goto error;
 	}
-	pr_debug("using %s zpool\n", zpool_get_type(pool->zpools[0]));
+	pr_debug("using %s zpool\n", zpool_get_type(pool->zpool));
 
 	strscpy(pool->tfm_name, compressor, sizeof(pool->tfm_name));
 
@@ -318,8 +310,8 @@ ref_fail:
 error:
 	if (pool->acomp_ctx)
 		free_percpu(pool->acomp_ctx);
-	while (i--)
-		zpool_destroy_pool(pool->zpools[i]);
+	if (pool->zpool)
+		zpool_destroy_pool(pool->zpool);
 	kfree(pool);
 	return NULL;
 }
@@ -368,15 +360,12 @@ static struct zswap_pool *__zswap_pool_create_fallback(void)
 
 static void zswap_pool_destroy(struct zswap_pool *pool)
 {
-	int i;
-
 	zswap_pool_debug("destroying", pool);
 
 	cpuhp_state_remove_instance(CPUHP_MM_ZSWP_POOL_PREPARE, &pool->node);
 	free_percpu(pool->acomp_ctx);
 
-	for (i = 0; i < ZSWAP_NR_ZPOOLS; i++)
-		zpool_destroy_pool(pool->zpools[i]);
+	zpool_destroy_pool(pool->zpool);
 	kfree(pool);
 }
 
@@ -471,8 +460,7 @@ static struct zswap_pool *zswap_pool_find_get(char *type, char *compressor)
 	list_for_each_entry_rcu(pool, &zswap_pools, list) {
 		if (strcmp(pool->tfm_name, compressor))
 			continue;
-		/* all zpools share the same type */
-		if (strcmp(zpool_get_type(pool->zpools[0]), type))
+		if (strcmp(zpool_get_type(pool->zpool), type))
 			continue;
 		/* if we can't get it, it's about to be destroyed */
 		if (!zswap_pool_get(pool))
@@ -499,12 +487,8 @@ unsigned long zswap_total_pages(void)
 	unsigned long total = 0;
 
 	rcu_read_lock();
-	list_for_each_entry_rcu(pool, &zswap_pools, list) {
-		int i;
-
-		for (i = 0; i < ZSWAP_NR_ZPOOLS; i++)
-			total += zpool_get_total_pages(pool->zpools[i]);
-	}
+	list_for_each_entry_rcu(pool, &zswap_pools, list)
+		total += zpool_get_total_pages(pool->zpool);
 	rcu_read_unlock();
 
 	return total;
@@ -809,11 +793,6 @@ static void zswap_entry_cache_free(struct zswap_entry *entry)
 	kmem_cache_free(zswap_entry_cache, entry);
 }
 
-static struct zpool *zswap_find_zpool(struct zswap_entry *entry)
-{
-	return entry->pool->zpools[hash_ptr(entry, ilog2(ZSWAP_NR_ZPOOLS))];
-}
-
 /*
  * Carries out the common pattern of freeing and entry's zpool allocation,
  * freeing the entry itself, and decrementing the number of stored pages.
@@ -824,7 +803,7 @@ static void zswap_entry_free(struct zswap_entry *entry)
 		atomic_dec(&zswap_same_filled_pages);
 	else {
 		zswap_lru_del(&zswap_list_lru, entry);
-		zpool_free(zswap_find_zpool(entry), entry->handle);
+	zpool_free(entry->pool->zpool, entry->handle);
 		zswap_pool_put(entry->pool);
 	}
 	if (entry->objcg) {
@@ -950,7 +929,7 @@ static bool zswap_compress(struct folio *folio, struct zswap_entry *entry)
 	if (comp_ret)
 		goto unlock;
 
-	zpool = zswap_find_zpool(entry);
+	zpool = entry->pool->zpool;
 	gfp = __GFP_NORETRY | __GFP_NOWARN | __GFP_KSWAPD_RECLAIM;
 	if (zpool_malloc_support_movable(zpool))
 		gfp |= __GFP_HIGHMEM | __GFP_MOVABLE;
@@ -979,7 +958,7 @@ unlock:
 
 static void zswap_decompress(struct zswap_entry *entry, struct folio *folio)
 {
-	struct zpool *zpool = zswap_find_zpool(entry);
+	struct zpool *zpool = entry->pool->zpool;
 	struct scatterlist input, output;
 	struct crypto_acomp_ctx *acomp_ctx;
 	u8 *src;
@@ -1531,7 +1510,7 @@ store_failed:
 	if (!entry->length)
 		atomic_dec(&zswap_same_filled_pages);
 	else {
-		zpool_free(zswap_find_zpool(entry), entry->handle);
+		zpool_free(entry->pool->zpool, entry->handle);
 put_pool:
 		zswap_pool_put(entry->pool);
 	}
@@ -1753,7 +1732,7 @@ static int zswap_setup(void)
 	pool = __zswap_pool_create_fallback();
 	if (pool) {
 		pr_info("loaded using pool %s/%s\n", pool->tfm_name,
-			zpool_get_type(pool->zpools[0]));
+			zpool_get_type(pool->zpool));
 		list_add(&pool->list, &zswap_pools);
 		zswap_has_pool = true;
 		static_branch_enable(&zswap_ever_enabled);