diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index bf7ae01fc93bafd193aeeabe3cbdf0ed7e63cd51..f94efd2f6c275b0ff14859e2451da53a6e3115a9 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -144,6 +144,8 @@ static inline bool mem_cgroup_disabled(void) void __mem_cgroup_begin_update_page_stat(struct page *page, bool *locked, unsigned long *flags); +extern atomic_t memcg_moving; + static inline void mem_cgroup_begin_update_page_stat(struct page *page, bool *locked, unsigned long *flags) { @@ -151,7 +153,8 @@ static inline void mem_cgroup_begin_update_page_stat(struct page *page, return; rcu_read_lock(); *locked = false; - return __mem_cgroup_begin_update_page_stat(page, locked, flags); + if (atomic_read(&memcg_moving)) + __mem_cgroup_begin_update_page_stat(page, locked, flags); } void __mem_cgroup_end_update_page_stat(struct page *page, diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 0e13b2aeea610207e76351902b56885253409930..eb1004f207b3c869fb331c8a21f4ffbe453e373f 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1306,8 +1306,13 @@ int mem_cgroup_swappiness(struct mem_cgroup *memcg) * rcu_read_unlock() * start move here. */ + +/* for quick checking without looking up memcg */ +atomic_t memcg_moving __read_mostly; + static void mem_cgroup_start_move(struct mem_cgroup *memcg) { + atomic_inc(&memcg_moving); atomic_inc(&memcg->moving_account); synchronize_rcu(); } @@ -1318,8 +1323,10 @@ static void mem_cgroup_end_move(struct mem_cgroup *memcg) * Now, mem_cgroup_clear_mc() may call this function with NULL. * We check NULL in callee rather than caller. */ - if (memcg) + if (memcg) { + atomic_dec(&memcg_moving); atomic_dec(&memcg->moving_account); + } } /*