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[2a03:2880:ff:13::face:b00c]) by smtp.gmail.com with ESMTPSA id y17-20020aa79e11000000b0056be4dbd4besm3363241pfq.111.2022.10.26.13.06.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 26 Oct 2022 13:06:17 -0700 (PDT) From: Nhat Pham To: akpm@linux-foundation.org Cc: hannes@cmpxchg.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, minchan@kernel.org, ngupta@vflare.org, senozhatsky@chromium.org, sjenning@redhat.com, ddstreet@ieee.org, vitaly.wool@konsulko.com Subject: [PATCH 3/5] zsmalloc: Add a LRU to zs_pool to keep track of zspages in LRU order Date: Wed, 26 Oct 2022 13:06:11 -0700 Message-Id: <20221026200613.1031261-4-nphamcs@gmail.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20221026200613.1031261-1-nphamcs@gmail.com> References: <20221026200613.1031261-1-nphamcs@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" This helps determines the coldest zspages as candidates for writeback. Signed-off-by: Nhat Pham Acked-by: Johannes Weiner --- mm/zsmalloc.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index 326faa751f0a..600c40121544 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -239,6 +239,9 @@ struct zs_pool { /* Compact classes */ struct shrinker shrinker; =20 + /* List tracking the zspages in LRU order by most recently added object */ + struct list_head lru; + #ifdef CONFIG_ZSMALLOC_STAT struct dentry *stat_dentry; #endif @@ -260,6 +263,10 @@ struct zspage { unsigned int freeobj; struct page *first_page; struct list_head list; /* fullness list */ + + /* links the zspage to the lru list in the pool */ + struct list_head lru; + struct zs_pool *pool; #ifdef CONFIG_COMPACTION rwlock_t lock; @@ -352,6 +359,16 @@ static void cache_free_zspage(struct zs_pool *pool, st= ruct zspage *zspage) kmem_cache_free(pool->zspage_cachep, zspage); } =20 +/* Moves the zspage to the front of the zspool's LRU */ +static void move_to_front(struct zs_pool *pool, struct zspage *zspage) +{ + assert_spin_locked(&pool->lock); + + if (!list_empty(&zspage->lru)) + list_del(&zspage->lru); + list_add(&zspage->lru, &pool->lru); +} + /* pool->lock(which owns the handle) synchronizes races */ static void record_obj(unsigned long handle, unsigned long obj) { @@ -953,6 +970,7 @@ static void free_zspage(struct zs_pool *pool, struct si= ze_class *class, } =20 remove_zspage(class, zspage, ZS_EMPTY); + list_del(&zspage->lru); __free_zspage(pool, class, zspage); } =20 @@ -998,6 +1016,8 @@ static void init_zspage(struct size_class *class, stru= ct zspage *zspage) off %=3D PAGE_SIZE; } =20 + INIT_LIST_HEAD(&zspage->lru); + set_freeobj(zspage, 0); } =20 @@ -1418,6 +1438,8 @@ unsigned long zs_malloc(struct zs_pool *pool, size_t = size, gfp_t gfp) fix_fullness_group(class, zspage); record_obj(handle, obj); class_stat_inc(class, OBJ_USED, 1); + /* Move the zspage to front of pool's LRU */ + move_to_front(pool, zspage); spin_unlock(&pool->lock); =20 return handle; @@ -1444,6 +1466,8 @@ unsigned long zs_malloc(struct zs_pool *pool, size_t = size, gfp_t gfp) =20 /* We completely set up zspage so mark them as movable */ SetZsPageMovable(pool, zspage); + /* Move the zspage to front of pool's LRU */ + move_to_front(pool, zspage); spin_unlock(&pool->lock); =20 return handle; @@ -1967,6 +1991,7 @@ static void async_free_zspage(struct work_struct *wor= k) VM_BUG_ON(fullness !=3D ZS_EMPTY); class =3D pool->size_class[class_idx]; spin_lock(&pool->lock); + list_del(&zspage->lru); __free_zspage(pool, class, zspage); spin_unlock(&pool->lock); } @@ -2278,6 +2303,8 @@ struct zs_pool *zs_create_pool(const char *name) */ zs_register_shrinker(pool); =20 + INIT_LIST_HEAD(&pool->lru); + return pool; =20 err: --=20 2.30.2