mm: simplify lock_page_memcg()

Now that migration doesn't clear page->mem_cgroup of live pages anymore,
it's safe to make lock_page_memcg() and the memcg stat functions take
pages, and spare the callers from memcg objects.

[akpm@linux-foundation.org: fix warnings]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Suggested-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/buffer.c b/fs/buffer.c
index dc991510bb06d01b2c4d89569a4ac62e0cdb7182..33be29675358321117038674a770e814a690e9fb 100644 (file)
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -624,14 +624,14 @@ EXPORT_SYMBOL(mark_buffer_dirty_inode);
  * The caller must hold lock_page_memcg().
  */
 static void __set_page_dirty(struct page *page, struct address_space *mapping,
-                            struct mem_cgroup *memcg, int warn)
+                            int warn)
 {
        unsigned long flags;
 
        spin_lock_irqsave(&mapping->tree_lock, flags);
        if (page->mapping) {    /* Race with truncate? */
                WARN_ON_ONCE(warn && !PageUptodate(page));
-               account_page_dirtied(page, mapping, memcg);
+               account_page_dirtied(page, mapping);
                radix_tree_tag_set(&mapping->page_tree,
                                page_index(page), PAGECACHE_TAG_DIRTY);
        }
@@ -666,7 +666,6 @@ static void __set_page_dirty(struct page *page, struct address_space *mapping,
 int __set_page_dirty_buffers(struct page *page)
 {
        int newly_dirty;
-       struct mem_cgroup *memcg;
        struct address_space *mapping = page_mapping(page);
 
        if (unlikely(!mapping))
@@ -686,14 +685,14 @@ int __set_page_dirty_buffers(struct page *page)
         * Lock out page->mem_cgroup migration to keep PageDirty
         * synchronized with per-memcg dirty page counters.
         */
-       memcg = lock_page_memcg(page);
+       lock_page_memcg(page);
        newly_dirty = !TestSetPageDirty(page);
        spin_unlock(&mapping->private_lock);
 
        if (newly_dirty)
-               __set_page_dirty(page, mapping, memcg, 1);
+               __set_page_dirty(page, mapping, 1);
 
-       unlock_page_memcg(memcg);
+       unlock_page_memcg(page);
 
        if (newly_dirty)
                __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
@@ -1167,15 +1166,14 @@ void mark_buffer_dirty(struct buffer_head *bh)
        if (!test_set_buffer_dirty(bh)) {
                struct page *page = bh->b_page;
                struct address_space *mapping = NULL;
-               struct mem_cgroup *memcg;
 
-               memcg = lock_page_memcg(page);
+               lock_page_memcg(page);
                if (!TestSetPageDirty(page)) {
                        mapping = page_mapping(page);
                        if (mapping)
-                               __set_page_dirty(page, mapping, memcg, 0);
+                               __set_page_dirty(page, mapping, 0);
                }
-               unlock_page_memcg(memcg);
+               unlock_page_memcg(page);
                if (mapping)
                        __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
        }

diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 5f85ebc52a98d0d75232e659492fb7368d4965be..5c57b7b40728904e0ad9c5641563df57400e76f9 100644 (file)
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -1957,7 +1957,6 @@ xfs_vm_set_page_dirty(
        loff_t                  end_offset;
        loff_t                  offset;
        int                     newly_dirty;
-       struct mem_cgroup       *memcg;
 
        if (unlikely(!mapping))
                return !TestSetPageDirty(page);
@@ -1981,7 +1980,7 @@ xfs_vm_set_page_dirty(
         * Lock out page->mem_cgroup migration to keep PageDirty
         * synchronized with per-memcg dirty page counters.
         */
-       memcg = lock_page_memcg(page);
+       lock_page_memcg(page);
        newly_dirty = !TestSetPageDirty(page);
        spin_unlock(&mapping->private_lock);
 
@@ -1992,13 +1991,13 @@ xfs_vm_set_page_dirty(
                spin_lock_irqsave(&mapping->tree_lock, flags);
                if (page->mapping) {    /* Race with truncate? */
                        WARN_ON_ONCE(!PageUptodate(page));
-                       account_page_dirtied(page, mapping, memcg);
+                       account_page_dirtied(page, mapping);
                        radix_tree_tag_set(&mapping->page_tree,
                                        page_index(page), PAGECACHE_TAG_DIRTY);
                }
                spin_unlock_irqrestore(&mapping->tree_lock, flags);
        }
-       unlock_page_memcg(memcg);
+       unlock_page_memcg(page);
        if (newly_dirty)
                __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
        return newly_dirty;

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index c45ab3fb6e04d1af8ecf4f9291209256b92188a8..d560c9a3cadf2d438afc08452932a68b1dfc83f2 100644 (file)
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -455,42 +455,42 @@ bool mem_cgroup_oom_synchronize(bool wait);
 extern int do_swap_account;
 #endif
 
-struct mem_cgroup *lock_page_memcg(struct page *page);
-void unlock_page_memcg(struct mem_cgroup *memcg);
+void lock_page_memcg(struct page *page);
+void unlock_page_memcg(struct page *page);
 
 /**
  * mem_cgroup_update_page_stat - update page state statistics
- * @memcg: memcg to account against
+ * @page: the page
  * @idx: page state item to account
  * @val: number of pages (positive or negative)
  *
  * Callers must use lock_page_memcg() to prevent double accounting
  * when the page is concurrently being moved to another memcg:
  *
- *   memcg = lock_page_memcg(page);
+ *   lock_page_memcg(page);
  *   if (TestClearPageState(page))
- *     mem_cgroup_update_page_stat(memcg, state, -1);
- *   unlock_page_memcg(memcg);
+ *     mem_cgroup_update_page_stat(page, state, -1);
+ *   unlock_page_memcg(page);
  */
-static inline void mem_cgroup_update_page_stat(struct mem_cgroup *memcg,
+static inline void mem_cgroup_update_page_stat(struct page *page,
                                 enum mem_cgroup_stat_index idx, int val)
 {
        VM_BUG_ON(!rcu_read_lock_held());
 
-       if (memcg)
-               this_cpu_add(memcg->stat->count[idx], val);
+       if (page->mem_cgroup)
+               this_cpu_add(page->mem_cgroup->stat->count[idx], val);
 }
 
-static inline void mem_cgroup_inc_page_stat(struct mem_cgroup *memcg,
+static inline void mem_cgroup_inc_page_stat(struct page *page,
                                            enum mem_cgroup_stat_index idx)
 {
-       mem_cgroup_update_page_stat(memcg, idx, 1);
+       mem_cgroup_update_page_stat(page, idx, 1);
 }
 
-static inline void mem_cgroup_dec_page_stat(struct mem_cgroup *memcg,
+static inline void mem_cgroup_dec_page_stat(struct page *page,
                                            enum mem_cgroup_stat_index idx)
 {
-       mem_cgroup_update_page_stat(memcg, idx, -1);
+       mem_cgroup_update_page_stat(page, idx, -1);
 }
 
 unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
@@ -661,12 +661,11 @@ mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
 {
 }
 
-static inline struct mem_cgroup *lock_page_memcg(struct page *page)
+static inline void lock_page_memcg(struct page *page)
 {
-       return NULL;
 }
 
-static inline void unlock_page_memcg(struct mem_cgroup *memcg)
+static inline void unlock_page_memcg(struct page *page)
 {
 }
 
@@ -692,12 +691,12 @@ static inline bool mem_cgroup_oom_synchronize(bool wait)
        return false;
 }
 
-static inline void mem_cgroup_inc_page_stat(struct mem_cgroup *memcg,
+static inline void mem_cgroup_inc_page_stat(struct page *page,
                                            enum mem_cgroup_stat_index idx)
 {
 }
 
-static inline void mem_cgroup_dec_page_stat(struct mem_cgroup *memcg,
+static inline void mem_cgroup_dec_page_stat(struct page *page,
                                            enum mem_cgroup_stat_index idx)
 {
 }

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 6b471d1fc8df45c17356872e0bf6abf885b77d28..a862b4f0ac24b27a5aae811f33b3debb1e47e6db 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1291,10 +1291,9 @@ int __set_page_dirty_nobuffers(struct page *page);
 int __set_page_dirty_no_writeback(struct page *page);
 int redirty_page_for_writepage(struct writeback_control *wbc,
                                struct page *page);
-void account_page_dirtied(struct page *page, struct address_space *mapping,
-                         struct mem_cgroup *memcg);
+void account_page_dirtied(struct page *page, struct address_space *mapping);
 void account_page_cleaned(struct page *page, struct address_space *mapping,
-                         struct mem_cgroup *memcg, struct bdi_writeback *wb);
+                         struct bdi_writeback *wb);
 int set_page_dirty(struct page *page);
 int set_page_dirty_lock(struct page *page);
 void cancel_dirty_page(struct page *page);

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 92395a0a7dc5c436cdd43317a798b6d15eba5a5e..183b15ea052ba1abe1ce8831c99efc323438e284 100644 (file)
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -663,8 +663,7 @@ int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
 int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
                                pgoff_t index, gfp_t gfp_mask);
 extern void delete_from_page_cache(struct page *page);
-extern void __delete_from_page_cache(struct page *page, void *shadow,
-                                    struct mem_cgroup *memcg);
+extern void __delete_from_page_cache(struct page *page, void *shadow);
 int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask);
 
 /*

diff --git a/mm/filemap.c b/mm/filemap.c
index d8317caffe85128af4fa3aa26f8e9bdca25f8e93..8e629c4ef0c8b0298865c775b490b698e667480e 100644 (file)
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -179,8 +179,7 @@ static void page_cache_tree_delete(struct address_space *mapping,
  * is safe.  The caller must hold the mapping's tree_lock and
  * lock_page_memcg().
  */
-void __delete_from_page_cache(struct page *page, void *shadow,
-                             struct mem_cgroup *memcg)
+void __delete_from_page_cache(struct page *page, void *shadow)
 {
        struct address_space *mapping = page->mapping;
 
@@ -239,8 +238,7 @@ void __delete_from_page_cache(struct page *page, void *shadow,
         * anyway will be cleared before returning page into buddy allocator.
         */
        if (WARN_ON_ONCE(PageDirty(page)))
-               account_page_cleaned(page, mapping, memcg,
-                                    inode_to_wb(mapping->host));
+               account_page_cleaned(page, mapping, inode_to_wb(mapping->host));
 }
 
 /**
@@ -254,7 +252,6 @@ void __delete_from_page_cache(struct page *page, void *shadow,
 void delete_from_page_cache(struct page *page)
 {
        struct address_space *mapping = page->mapping;
-       struct mem_cgroup *memcg;
        unsigned long flags;
 
        void (*freepage)(struct page *);
@@ -263,11 +260,11 @@ void delete_from_page_cache(struct page *page)
 
        freepage = mapping->a_ops->freepage;
 
-       memcg = lock_page_memcg(page);
+       lock_page_memcg(page);
        spin_lock_irqsave(&mapping->tree_lock, flags);
-       __delete_from_page_cache(page, NULL, memcg);
+       __delete_from_page_cache(page, NULL);
        spin_unlock_irqrestore(&mapping->tree_lock, flags);
-       unlock_page_memcg(memcg);
+       unlock_page_memcg(page);
 
        if (freepage)
                freepage(page);
@@ -551,7 +548,6 @@ int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask)
        if (!error) {
                struct address_space *mapping = old->mapping;
                void (*freepage)(struct page *);
-               struct mem_cgroup *memcg;
                unsigned long flags;
 
                pgoff_t offset = old->index;
@@ -561,9 +557,9 @@ int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask)
                new->mapping = mapping;
                new->index = offset;
 
-               memcg = lock_page_memcg(old);
+               lock_page_memcg(old);
                spin_lock_irqsave(&mapping->tree_lock, flags);
-               __delete_from_page_cache(old, NULL, memcg);
+               __delete_from_page_cache(old, NULL);
                error = radix_tree_insert(&mapping->page_tree, offset, new);
                BUG_ON(error);
                mapping->nrpages++;
@@ -576,7 +572,7 @@ int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask)
                if (PageSwapBacked(new))
                        __inc_zone_page_state(new, NR_SHMEM);
                spin_unlock_irqrestore(&mapping->tree_lock, flags);
-               unlock_page_memcg(memcg);
+               unlock_page_memcg(old);
                mem_cgroup_migrate(old, new);
                radix_tree_preload_end();
                if (freepage)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 64506b2eef3479dc190ec93f48f2852e32a7b7cf..3e41998304564bba68933962c800db0781a79015 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1690,7 +1690,7 @@ cleanup:
  * This function protects unlocked LRU pages from being moved to
  * another cgroup and stabilizes their page->mem_cgroup binding.
  */
-struct mem_cgroup *lock_page_memcg(struct page *page)
+void lock_page_memcg(struct page *page)
 {
        struct mem_cgroup *memcg;
        unsigned long flags;
@@ -1699,25 +1699,18 @@ struct mem_cgroup *lock_page_memcg(struct page *page)
         * The RCU lock is held throughout the transaction.  The fast
         * path can get away without acquiring the memcg->move_lock
         * because page moving starts with an RCU grace period.
-        *
-        * The RCU lock also protects the memcg from being freed when
-        * the page state that is going to change is the only thing
-        * preventing the page from being uncharged.
-        * E.g. end-writeback clearing PageWriteback(), which allows
-        * migration to go ahead and uncharge the page before the
-        * account transaction might be complete.
         */
        rcu_read_lock();
 
        if (mem_cgroup_disabled())
-               return NULL;
+               return;
 again:
        memcg = page->mem_cgroup;
        if (unlikely(!memcg))
-               return NULL;
+               return;
 
        if (atomic_read(&memcg->moving_account) <= 0)
-               return memcg;
+               return;
 
        spin_lock_irqsave(&memcg->move_lock, flags);
        if (memcg != page->mem_cgroup) {
@@ -1733,16 +1726,18 @@ again:
        memcg->move_lock_task = current;
        memcg->move_lock_flags = flags;
 
-       return memcg;
+       return;
 }
 EXPORT_SYMBOL(lock_page_memcg);
 
 /**
  * unlock_page_memcg - unlock a page->mem_cgroup binding
- * @memcg: the memcg returned by lock_page_memcg()
+ * @page: the page
  */
-void unlock_page_memcg(struct mem_cgroup *memcg)
+void unlock_page_memcg(struct page *page)
 {
+       struct mem_cgroup *memcg = page->mem_cgroup;
+
        if (memcg && memcg->move_lock_task == current) {
                unsigned long flags = memcg->move_lock_flags;
 

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 2b5ea1271e327c381c76b833d4485891e67d531a..d7cf2c53d1254beddd13ca6129095db24790f952 100644 (file)
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -2414,8 +2414,7 @@ int __set_page_dirty_no_writeback(struct page *page)
  *
  * NOTE: This relies on being atomic wrt interrupts.
  */
-void account_page_dirtied(struct page *page, struct address_space *mapping,
-                         struct mem_cgroup *memcg)
+void account_page_dirtied(struct page *page, struct address_space *mapping)
 {
        struct inode *inode = mapping->host;
 
@@ -2427,7 +2426,7 @@ void account_page_dirtied(struct page *page, struct address_space *mapping,
                inode_attach_wb(inode, page);
                wb = inode_to_wb(inode);
 
-               mem_cgroup_inc_page_stat(memcg, MEM_CGROUP_STAT_DIRTY);
+               mem_cgroup_inc_page_stat(page, MEM_CGROUP_STAT_DIRTY);
                __inc_zone_page_state(page, NR_FILE_DIRTY);
                __inc_zone_page_state(page, NR_DIRTIED);
                __inc_wb_stat(wb, WB_RECLAIMABLE);
@@ -2445,10 +2444,10 @@ EXPORT_SYMBOL(account_page_dirtied);
  * Caller must hold lock_page_memcg().
  */
 void account_page_cleaned(struct page *page, struct address_space *mapping,
-                         struct mem_cgroup *memcg, struct bdi_writeback *wb)
+                         struct bdi_writeback *wb)
 {
        if (mapping_cap_account_dirty(mapping)) {
-               mem_cgroup_dec_page_stat(memcg, MEM_CGROUP_STAT_DIRTY);
+               mem_cgroup_dec_page_stat(page, MEM_CGROUP_STAT_DIRTY);
                dec_zone_page_state(page, NR_FILE_DIRTY);
                dec_wb_stat(wb, WB_RECLAIMABLE);
                task_io_account_cancelled_write(PAGE_CACHE_SIZE);
@@ -2469,26 +2468,24 @@ void account_page_cleaned(struct page *page, struct address_space *mapping,
  */
 int __set_page_dirty_nobuffers(struct page *page)
 {
-       struct mem_cgroup *memcg;
-
-       memcg = lock_page_memcg(page);
+       lock_page_memcg(page);
        if (!TestSetPageDirty(page)) {
                struct address_space *mapping = page_mapping(page);
                unsigned long flags;
 
                if (!mapping) {
-                       unlock_page_memcg(memcg);
+                       unlock_page_memcg(page);
                        return 1;
                }
 
                spin_lock_irqsave(&mapping->tree_lock, flags);
                BUG_ON(page_mapping(page) != mapping);
                WARN_ON_ONCE(!PagePrivate(page) && !PageUptodate(page));
-               account_page_dirtied(page, mapping, memcg);
+               account_page_dirtied(page, mapping);
                radix_tree_tag_set(&mapping->page_tree, page_index(page),
                                   PAGECACHE_TAG_DIRTY);
                spin_unlock_irqrestore(&mapping->tree_lock, flags);
-               unlock_page_memcg(memcg);
+               unlock_page_memcg(page);
 
                if (mapping->host) {
                        /* !PageAnon && !swapper_space */
@@ -2496,7 +2493,7 @@ int __set_page_dirty_nobuffers(struct page *page)
                }
                return 1;
        }
-       unlock_page_memcg(memcg);
+       unlock_page_memcg(page);
        return 0;
 }
 EXPORT_SYMBOL(__set_page_dirty_nobuffers);
@@ -2626,17 +2623,16 @@ void cancel_dirty_page(struct page *page)
        if (mapping_cap_account_dirty(mapping)) {
                struct inode *inode = mapping->host;
                struct bdi_writeback *wb;
-               struct mem_cgroup *memcg;
                bool locked;
 
-               memcg = lock_page_memcg(page);
+               lock_page_memcg(page);
                wb = unlocked_inode_to_wb_begin(inode, &locked);
 
                if (TestClearPageDirty(page))
-                       account_page_cleaned(page, mapping, memcg, wb);
+                       account_page_cleaned(page, mapping, wb);
 
                unlocked_inode_to_wb_end(inode, locked);
-               unlock_page_memcg(memcg);
+               unlock_page_memcg(page);
        } else {
                ClearPageDirty(page);
        }
@@ -2667,7 +2663,6 @@ int clear_page_dirty_for_io(struct page *page)
        if (mapping && mapping_cap_account_dirty(mapping)) {
                struct inode *inode = mapping->host;
                struct bdi_writeback *wb;
-               struct mem_cgroup *memcg;
                bool locked;
 
                /*
@@ -2705,16 +2700,16 @@ int clear_page_dirty_for_io(struct page *page)
                 * always locked coming in here, so we get the desired
                 * exclusion.
                 */
-               memcg = lock_page_memcg(page);
+               lock_page_memcg(page);
                wb = unlocked_inode_to_wb_begin(inode, &locked);
                if (TestClearPageDirty(page)) {
-                       mem_cgroup_dec_page_stat(memcg, MEM_CGROUP_STAT_DIRTY);
+                       mem_cgroup_dec_page_stat(page, MEM_CGROUP_STAT_DIRTY);
                        dec_zone_page_state(page, NR_FILE_DIRTY);
                        dec_wb_stat(wb, WB_RECLAIMABLE);
                        ret = 1;
                }
                unlocked_inode_to_wb_end(inode, locked);
-               unlock_page_memcg(memcg);
+               unlock_page_memcg(page);
                return ret;
        }
        return TestClearPageDirty(page);
@@ -2724,10 +2719,9 @@ EXPORT_SYMBOL(clear_page_dirty_for_io);
 int test_clear_page_writeback(struct page *page)
 {
        struct address_space *mapping = page_mapping(page);
-       struct mem_cgroup *memcg;
        int ret;
 
-       memcg = lock_page_memcg(page);
+       lock_page_memcg(page);
        if (mapping) {
                struct inode *inode = mapping->host;
                struct backing_dev_info *bdi = inode_to_bdi(inode);
@@ -2751,21 +2745,20 @@ int test_clear_page_writeback(struct page *page)
                ret = TestClearPageWriteback(page);
        }
        if (ret) {
-               mem_cgroup_dec_page_stat(memcg, MEM_CGROUP_STAT_WRITEBACK);
+               mem_cgroup_dec_page_stat(page, MEM_CGROUP_STAT_WRITEBACK);
                dec_zone_page_state(page, NR_WRITEBACK);
                inc_zone_page_state(page, NR_WRITTEN);
        }
-       unlock_page_memcg(memcg);
+       unlock_page_memcg(page);
        return ret;
 }
 
 int __test_set_page_writeback(struct page *page, bool keep_write)
 {
        struct address_space *mapping = page_mapping(page);
-       struct mem_cgroup *memcg;
        int ret;
 
-       memcg = lock_page_memcg(page);
+       lock_page_memcg(page);
        if (mapping) {
                struct inode *inode = mapping->host;
                struct backing_dev_info *bdi = inode_to_bdi(inode);
@@ -2793,10 +2786,10 @@ int __test_set_page_writeback(struct page *page, bool keep_write)
                ret = TestSetPageWriteback(page);
        }
        if (!ret) {
-               mem_cgroup_inc_page_stat(memcg, MEM_CGROUP_STAT_WRITEBACK);
+               mem_cgroup_inc_page_stat(page, MEM_CGROUP_STAT_WRITEBACK);
                inc_zone_page_state(page, NR_WRITEBACK);
        }
-       unlock_page_memcg(memcg);
+       unlock_page_memcg(page);
        return ret;
 
 }

diff --git a/mm/rmap.c b/mm/rmap.c
index 2871e7d3ccedf551c0f4283f0028a43623dd2f02..02f0bfc3c80af93edb82b31307e44dc21a622ec1 100644 (file)
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1287,21 +1287,17 @@ void page_add_new_anon_rmap(struct page *page,
  */
 void page_add_file_rmap(struct page *page)
 {
-       struct mem_cgroup *memcg;
-
-       memcg = lock_page_memcg(page);
+       lock_page_memcg(page);
        if (atomic_inc_and_test(&page->_mapcount)) {
                __inc_zone_page_state(page, NR_FILE_MAPPED);
-               mem_cgroup_inc_page_stat(memcg, MEM_CGROUP_STAT_FILE_MAPPED);
+               mem_cgroup_inc_page_stat(page, MEM_CGROUP_STAT_FILE_MAPPED);
        }
-       unlock_page_memcg(memcg);
+       unlock_page_memcg(page);
 }
 
 static void page_remove_file_rmap(struct page *page)
 {
-       struct mem_cgroup *memcg;
-
-       memcg = lock_page_memcg(page);
+       lock_page_memcg(page);
 
        /* Hugepages are not counted in NR_FILE_MAPPED for now. */
        if (unlikely(PageHuge(page))) {
@@ -1320,12 +1316,12 @@ static void page_remove_file_rmap(struct page *page)
         * pte lock(a spinlock) is held, which implies preemption disabled.
         */
        __dec_zone_page_state(page, NR_FILE_MAPPED);
-       mem_cgroup_dec_page_stat(memcg, MEM_CGROUP_STAT_FILE_MAPPED);
+       mem_cgroup_dec_page_stat(page, MEM_CGROUP_STAT_FILE_MAPPED);
 
        if (unlikely(PageMlocked(page)))
                clear_page_mlock(page);
 out:
-       unlock_page_memcg(memcg);
+       unlock_page_memcg(page);
 }
 
 static void page_remove_anon_compound_rmap(struct page *page)

diff --git a/mm/truncate.c b/mm/truncate.c
index 51a24f6a555d7cd5b7c3615b637d365ae3b2740a..87311af936f2c0a68bae6c8768c84996c4cf1fe1 100644 (file)
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -519,7 +519,6 @@ EXPORT_SYMBOL(invalidate_mapping_pages);
 static int
 invalidate_complete_page2(struct address_space *mapping, struct page *page)
 {
-       struct mem_cgroup *memcg;
        unsigned long flags;
 
        if (page->mapping != mapping)
@@ -528,15 +527,15 @@ invalidate_complete_page2(struct address_space *mapping, struct page *page)
        if (page_has_private(page) && !try_to_release_page(page, GFP_KERNEL))
                return 0;
 
-       memcg = lock_page_memcg(page);
+       lock_page_memcg(page);
        spin_lock_irqsave(&mapping->tree_lock, flags);
        if (PageDirty(page))
                goto failed;
 
        BUG_ON(page_has_private(page));
-       __delete_from_page_cache(page, NULL, memcg);
+       __delete_from_page_cache(page, NULL);
        spin_unlock_irqrestore(&mapping->tree_lock, flags);
-       unlock_page_memcg(memcg);
+       unlock_page_memcg(page);
 
        if (mapping->a_ops->freepage)
                mapping->a_ops->freepage(page);
@@ -545,7 +544,7 @@ invalidate_complete_page2(struct address_space *mapping, struct page *page)
        return 1;
 failed:
        spin_unlock_irqrestore(&mapping->tree_lock, flags);
-       unlock_page_memcg(memcg);
+       unlock_page_memcg(page);
        return 0;
 }
 

diff --git a/mm/vmscan.c b/mm/vmscan.c
index fd434cc89bea99a9a0cafbe96c0431fc1c4ba8f6..34f7e2dae0a0d3d3c46850b51788a62318a5676d 100644 (file)
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -603,12 +603,11 @@ static int __remove_mapping(struct address_space *mapping, struct page *page,
                            bool reclaimed)
 {
        unsigned long flags;
-       struct mem_cgroup *memcg;
 
        BUG_ON(!PageLocked(page));
        BUG_ON(mapping != page_mapping(page));
 
-       memcg = lock_page_memcg(page);
+       lock_page_memcg(page);
        spin_lock_irqsave(&mapping->tree_lock, flags);
        /*
         * The non racy check for a busy page.
@@ -648,7 +647,7 @@ static int __remove_mapping(struct address_space *mapping, struct page *page,
                mem_cgroup_swapout(page, swap);
                __delete_from_swap_cache(page);
                spin_unlock_irqrestore(&mapping->tree_lock, flags);
-               unlock_page_memcg(memcg);
+               unlock_page_memcg(page);
                swapcache_free(swap);
        } else {
                void (*freepage)(struct page *);
@@ -674,9 +673,9 @@ static int __remove_mapping(struct address_space *mapping, struct page *page,
                if (reclaimed && page_is_file_cache(page) &&
                    !mapping_exiting(mapping) && !dax_mapping(mapping))
                        shadow = workingset_eviction(mapping, page);
-               __delete_from_page_cache(page, shadow, memcg);
+               __delete_from_page_cache(page, shadow);
                spin_unlock_irqrestore(&mapping->tree_lock, flags);
-               unlock_page_memcg(memcg);
+               unlock_page_memcg(page);
 
                if (freepage != NULL)
                        freepage(page);
@@ -686,7 +685,7 @@ static int __remove_mapping(struct address_space *mapping, struct page *page,
 
 cannot_free:
        spin_unlock_irqrestore(&mapping->tree_lock, flags);
-       unlock_page_memcg(memcg);
+       unlock_page_memcg(page);
        return 0;
 }
 

diff --git a/mm/workingset.c b/mm/workingset.c
index 14bc23a7779bd54ce4eab81e07dd569c5236c867..6130ba0b26415353e09c977a0f3d13cf94b76178 100644 (file)
--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -305,10 +305,9 @@ bool workingset_refault(void *shadow)
  */
 void workingset_activation(struct page *page)
 {
-       struct mem_cgroup *memcg;
        struct lruvec *lruvec;
 
-       memcg = lock_page_memcg(page);
+       lock_page_memcg(page);
        /*
         * Filter non-memcg pages here, e.g. unmap can call
         * mark_page_accessed() on VDSO pages.
@@ -316,12 +315,12 @@ void workingset_activation(struct page *page)
         * XXX: See workingset_refault() - this should return
         * root_mem_cgroup even for !CONFIG_MEMCG.
         */
-       if (!mem_cgroup_disabled() && !memcg)
+       if (!mem_cgroup_disabled() && !page_memcg(page))
                goto out;
-       lruvec = mem_cgroup_zone_lruvec(page_zone(page), memcg);
+       lruvec = mem_cgroup_zone_lruvec(page_zone(page), page_memcg(page));
        atomic_long_inc(&lruvec->inactive_age);
 out:
-       unlock_page_memcg(memcg);
+       unlock_page_memcg(page);
 }
 
 /*