diff options
Diffstat (limited to 'mm/memcontrol.c')
| -rw-r--r-- | mm/memcontrol.c | 34 |
1 files changed, 14 insertions, 20 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index d06cae2de783..953f0f984392 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1709,19 +1709,13 @@ cleanup: } /** - * mem_cgroup_begin_page_stat - begin a page state statistics transaction - * @page: page that is going to change accounted state - * - * This function must mark the beginning of an accounted page state - * change to prevent double accounting when the page is concurrently - * being moved to another memcg: + * lock_page_memcg - lock a page->mem_cgroup binding + * @page: the page * - * memcg = mem_cgroup_begin_page_stat(page); - * if (TestClearPageState(page)) - * mem_cgroup_update_page_stat(memcg, state, -1); - * mem_cgroup_end_page_stat(memcg); + * This function protects unlocked LRU pages from being moved to + * another cgroup and stabilizes their page->mem_cgroup binding. */ -struct mem_cgroup *mem_cgroup_begin_page_stat(struct page *page) +struct mem_cgroup *lock_page_memcg(struct page *page) { struct mem_cgroup *memcg; unsigned long flags; @@ -1759,20 +1753,20 @@ again: /* * When charge migration first begins, we can have locked and * unlocked page stat updates happening concurrently. Track - * the task who has the lock for mem_cgroup_end_page_stat(). + * the task who has the lock for unlock_page_memcg(). */ memcg->move_lock_task = current; memcg->move_lock_flags = flags; return memcg; } -EXPORT_SYMBOL(mem_cgroup_begin_page_stat); +EXPORT_SYMBOL(lock_page_memcg); /** - * mem_cgroup_end_page_stat - finish a page state statistics transaction - * @memcg: the memcg that was accounted against + * unlock_page_memcg - unlock a page->mem_cgroup binding + * @memcg: the memcg returned by lock_page_memcg() */ -void mem_cgroup_end_page_stat(struct mem_cgroup *memcg) +void unlock_page_memcg(struct mem_cgroup *memcg) { if (memcg && memcg->move_lock_task == current) { unsigned long flags = memcg->move_lock_flags; @@ -1785,7 +1779,7 @@ void mem_cgroup_end_page_stat(struct mem_cgroup *memcg) rcu_read_unlock(); } -EXPORT_SYMBOL(mem_cgroup_end_page_stat); +EXPORT_SYMBOL(unlock_page_memcg); /* * size of first charge trial. "32" comes from vmscan.c's magic value. @@ -4923,9 +4917,9 @@ static void mem_cgroup_move_charge(struct mm_struct *mm) lru_add_drain_all(); /* - * Signal mem_cgroup_begin_page_stat() to take the memcg's - * move_lock while we're moving its pages to another memcg. - * Then wait for already started RCU-only updates to finish. + * Signal lock_page_memcg() to take the memcg's move_lock + * while we're moving its pages to another memcg. Then wait + * for already started RCU-only updates to finish. */ atomic_inc(&mc.from->moving_account); synchronize_rcu(); |