diff --git a/mm/zswap.c b/mm/zswap.c index 62195f72bf56..258e4e17799a 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -142,6 +142,9 @@ static bool zswap_exclusive_loads_enabled = IS_ENABLED( CONFIG_ZSWAP_EXCLUSIVE_LOADS_DEFAULT_ON); module_param_named(exclusive_loads, zswap_exclusive_loads_enabled, bool, 0644); +/* Number of zpools in zswap_pool (empirically determined for scalability) */ +#define ZSWAP_NR_ZPOOLS 32 + /********************************* * data structures **********************************/ @@ -161,7 +164,7 @@ struct crypto_acomp_ctx { * needs to be verified that it's still valid in the tree. */ struct zswap_pool { - struct zpool *zpool; + struct zpool *zpools[ZSWAP_NR_ZPOOLS]; struct crypto_acomp_ctx __percpu *acomp_ctx; struct kref kref; struct list_head list; @@ -248,7 +251,7 @@ static bool zswap_has_pool; #define zswap_pool_debug(msg, p) \ pr_debug("%s pool %s/%s\n", msg, (p)->tfm_name, \ - zpool_get_type((p)->zpool)) + zpool_get_type((p)->zpools[0])) static int zswap_writeback_entry(struct zswap_entry *entry, struct zswap_tree *tree); @@ -272,11 +275,13 @@ static void zswap_update_total_size(void) { struct zswap_pool *pool; u64 total = 0; + int i; rcu_read_lock(); list_for_each_entry_rcu(pool, &zswap_pools, list) - total += zpool_get_total_size(pool->zpool); + for (i = 0; i < ZSWAP_NR_ZPOOLS; i++) + total += zpool_get_total_size(pool->zpools[i]); rcu_read_unlock(); @@ -365,6 +370,16 @@ static bool zswap_rb_erase(struct rb_root *root, struct zswap_entry *entry) return false; } +static struct zpool *zswap_find_zpool(struct zswap_entry *entry) +{ + int i = 0; + + if (ZSWAP_NR_ZPOOLS > 1) + i = hash_ptr(entry, ilog2(ZSWAP_NR_ZPOOLS)); + + return entry->pool->zpools[i]; +} + /* * Carries out the common pattern of freeing and entry's zpool allocation, * freeing the entry itself, and decrementing the number of stored pages. @@ -381,7 +396,7 @@ static void zswap_free_entry(struct zswap_entry *entry) spin_lock(&entry->pool->lru_lock); list_del(&entry->lru); spin_unlock(&entry->pool->lru_lock); - zpool_free(entry->pool->zpool, entry->handle); + zpool_free(zswap_find_zpool(entry), entry->handle); zswap_pool_put(entry->pool); } zswap_entry_cache_free(entry); @@ -590,7 +605,8 @@ 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; - if (strcmp(zpool_get_type(pool->zpool), type)) + /* all zpools share the same type */ + if (strcmp(zpool_get_type(pool->zpools[0]), type)) continue; /* if we can't get it, it's about to be destroyed */ if (!zswap_pool_get(pool)) @@ -695,6 +711,7 @@ static void shrink_worker(struct work_struct *w) 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; @@ -715,15 +732,18 @@ static struct zswap_pool *zswap_pool_create(char *type, char *compressor) if (!pool) return NULL; - /* unique name for each pool specifically required by zsmalloc */ - snprintf(name, 38, "zswap%x", atomic_inc_return(&zswap_pools_count)); + 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->zpool = zpool_create_pool(type, name, gfp); - if (!pool->zpool) { - pr_err("%s zpool not available\n", type); - goto error; + pool->zpools[i] = zpool_create_pool(type, name, gfp); + if (!pool->zpools[i]) { + pr_err("%s zpool not available\n", type); + goto error; + } } - pr_debug("using %s zpool\n", zpool_get_type(pool->zpool)); + pr_debug("using %s zpool\n", zpool_get_type(pool->zpools[0])); strscpy(pool->tfm_name, compressor, sizeof(pool->tfm_name)); @@ -755,8 +775,8 @@ static struct zswap_pool *zswap_pool_create(char *type, char *compressor) error: if (pool->acomp_ctx) free_percpu(pool->acomp_ctx); - if (pool->zpool) - zpool_destroy_pool(pool->zpool); + while (i--) + zpool_destroy_pool(pool->zpools[i]); kfree(pool); return NULL; } @@ -805,11 +825,14 @@ 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); - zpool_destroy_pool(pool->zpool); + for (i = 0; i < ZSWAP_NR_ZPOOLS; i++) + zpool_destroy_pool(pool->zpools[i]); kfree(pool); } @@ -1073,7 +1096,7 @@ static int zswap_writeback_entry(struct zswap_entry *entry, struct page *page; struct scatterlist input, output; struct crypto_acomp_ctx *acomp_ctx; - struct zpool *pool = entry->pool->zpool; + struct zpool *pool = zswap_find_zpool(entry); u8 *src, *tmp = NULL; unsigned int dlen; @@ -1214,6 +1237,7 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset, struct crypto_acomp_ctx *acomp_ctx; struct obj_cgroup *objcg = NULL; struct zswap_pool *pool; + struct zpool *zpool; int ret; unsigned int dlen = PAGE_SIZE; unsigned long handle, value; @@ -1324,10 +1348,11 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset, } /* store */ + zpool = zswap_find_zpool(entry); gfp = __GFP_NORETRY | __GFP_NOWARN | __GFP_KSWAPD_RECLAIM; - if (zpool_malloc_support_movable(entry->pool->zpool)) + if (zpool_malloc_support_movable(zpool)) gfp |= __GFP_HIGHMEM | __GFP_MOVABLE; - ret = zpool_malloc(entry->pool->zpool, dlen, gfp, &handle); + ret = zpool_malloc(zpool, dlen, gfp, &handle); if (ret == -ENOSPC) { zswap_reject_compress_poor++; goto put_dstmem; @@ -1336,9 +1361,9 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset, zswap_reject_alloc_fail++; goto put_dstmem; } - buf = zpool_map_handle(entry->pool->zpool, handle, ZPOOL_MM_WO); + buf = zpool_map_handle(zpool, handle, ZPOOL_MM_WO); memcpy(buf, dst, dlen); - zpool_unmap_handle(entry->pool->zpool, handle); + zpool_unmap_handle(zpool, handle); mutex_unlock(acomp_ctx->mutex); /* populate entry */ @@ -1409,6 +1434,7 @@ static int zswap_frontswap_load(unsigned type, pgoff_t offset, struct scatterlist input, output; struct crypto_acomp_ctx *acomp_ctx; u8 *src, *dst, *tmp; + struct zpool *zpool; unsigned int dlen; int ret; @@ -1430,7 +1456,8 @@ static int zswap_frontswap_load(unsigned type, pgoff_t offset, goto stats; } - if (!zpool_can_sleep_mapped(entry->pool->zpool)) { + zpool = zswap_find_zpool(entry); + if (!zpool_can_sleep_mapped(zpool)) { tmp = kmalloc(entry->length, GFP_KERNEL); if (!tmp) { ret = -ENOMEM; @@ -1440,12 +1467,12 @@ static int zswap_frontswap_load(unsigned type, pgoff_t offset, /* decompress */ dlen = PAGE_SIZE; - src = zpool_map_handle(entry->pool->zpool, entry->handle, ZPOOL_MM_RO); + src = zpool_map_handle(zpool, entry->handle, ZPOOL_MM_RO); - if (!zpool_can_sleep_mapped(entry->pool->zpool)) { + if (!zpool_can_sleep_mapped(zpool)) { memcpy(tmp, src, entry->length); src = tmp; - zpool_unmap_handle(entry->pool->zpool, entry->handle); + zpool_unmap_handle(zpool, entry->handle); } acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx); @@ -1457,8 +1484,8 @@ static int zswap_frontswap_load(unsigned type, pgoff_t offset, ret = crypto_wait_req(crypto_acomp_decompress(acomp_ctx->req), &acomp_ctx->wait); mutex_unlock(acomp_ctx->mutex); - if (zpool_can_sleep_mapped(entry->pool->zpool)) - zpool_unmap_handle(entry->pool->zpool, entry->handle); + if (zpool_can_sleep_mapped(zpool)) + zpool_unmap_handle(zpool, entry->handle); else kfree(tmp); @@ -1619,7 +1646,7 @@ 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->zpool)); + zpool_get_type(pool->zpools[0])); list_add(&pool->list, &zswap_pools); zswap_has_pool = true; } else {