Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / mm / memcontrol.c
index 556859fec4ef45fe87bd4060612501354ed48c9a..5585dc3d36466189b0d89adf8e86f424372bdd23 100644 (file)
@@ -776,7 +776,8 @@ static void memcg_check_events(struct mem_cgroup *memcg, struct page *page)
        /* threshold event is triggered in finer grain than soft limit */
        if (unlikely(mem_cgroup_event_ratelimit(memcg,
                                                MEM_CGROUP_TARGET_THRESH))) {
-               bool do_softlimit, do_numainfo;
+               bool do_softlimit;
+               bool do_numainfo __maybe_unused;
 
                do_softlimit = mem_cgroup_event_ratelimit(memcg,
                                                MEM_CGROUP_TARGET_SOFTLIMIT);
@@ -1041,6 +1042,19 @@ struct lruvec *mem_cgroup_lru_add_list(struct zone *zone, struct page *page,
 
        pc = lookup_page_cgroup(page);
        memcg = pc->mem_cgroup;
+
+       /*
+        * Surreptitiously switch any uncharged page to root:
+        * an uncharged page off lru does nothing to secure
+        * its former mem_cgroup from sudden removal.
+        *
+        * Our caller holds lru_lock, and PageCgroupUsed is updated
+        * under page_cgroup lock: between them, they make all uses
+        * of pc->mem_cgroup safe.
+        */
+       if (!PageCgroupUsed(pc) && memcg != root_mem_cgroup)
+               pc->mem_cgroup = memcg = root_mem_cgroup;
+
        mz = page_cgroup_zoneinfo(memcg, page);
        /* compound_order() is stabilized through lru_lock */
        MEM_CGROUP_ZSTAT(mz, lru) += 1 << compound_order(page);
@@ -2407,8 +2421,12 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg,
                                       struct page *page,
                                       unsigned int nr_pages,
                                       struct page_cgroup *pc,
-                                      enum charge_type ctype)
+                                      enum charge_type ctype,
+                                      bool lrucare)
 {
+       struct zone *uninitialized_var(zone);
+       bool was_on_lru = false;
+
        lock_page_cgroup(pc);
        if (unlikely(PageCgroupUsed(pc))) {
                unlock_page_cgroup(pc);
@@ -2419,6 +2437,21 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg,
         * we don't need page_cgroup_lock about tail pages, becase they are not
         * accessed by any other context at this point.
         */
+
+       /*
+        * In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
+        * may already be on some other mem_cgroup's LRU.  Take care of it.
+        */
+       if (lrucare) {
+               zone = page_zone(page);
+               spin_lock_irq(&zone->lru_lock);
+               if (PageLRU(page)) {
+                       ClearPageLRU(page);
+                       del_page_from_lru_list(zone, page, page_lru(page));
+                       was_on_lru = true;
+               }
+       }
+
        pc->mem_cgroup = memcg;
        /*
         * We access a page_cgroup asynchronously without lock_page_cgroup().
@@ -2442,9 +2475,18 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg,
                break;
        }
 
+       if (lrucare) {
+               if (was_on_lru) {
+                       VM_BUG_ON(PageLRU(page));
+                       SetPageLRU(page);
+                       add_page_to_lru_list(zone, page, page_lru(page));
+               }
+               spin_unlock_irq(&zone->lru_lock);
+       }
+
        mem_cgroup_charge_statistics(memcg, PageCgroupCache(pc), nr_pages);
        unlock_page_cgroup(pc);
-       WARN_ON_ONCE(PageLRU(page));
+
        /*
         * "charge_statistics" updated event counter. Then, check it.
         * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
@@ -2642,7 +2684,7 @@ static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
        ret = __mem_cgroup_try_charge(mm, gfp_mask, nr_pages, &memcg, oom);
        if (ret == -ENOMEM)
                return ret;
-       __mem_cgroup_commit_charge(memcg, page, nr_pages, pc, ctype);
+       __mem_cgroup_commit_charge(memcg, page, nr_pages, pc, ctype, false);
        return 0;
 }
 
@@ -2662,35 +2704,6 @@ static void
 __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
                                        enum charge_type ctype);
 
-static void
-__mem_cgroup_commit_charge_lrucare(struct page *page, struct mem_cgroup *memcg,
-                                       enum charge_type ctype)
-{
-       struct page_cgroup *pc = lookup_page_cgroup(page);
-       struct zone *zone = page_zone(page);
-       unsigned long flags;
-       bool removed = false;
-
-       /*
-        * In some case, SwapCache, FUSE(splice_buf->radixtree), the page
-        * is already on LRU. It means the page may on some other page_cgroup's
-        * LRU. Take care of it.
-        */
-       spin_lock_irqsave(&zone->lru_lock, flags);
-       if (PageLRU(page)) {
-               del_page_from_lru_list(zone, page, page_lru(page));
-               ClearPageLRU(page);
-               removed = true;
-       }
-       __mem_cgroup_commit_charge(memcg, page, 1, pc, ctype);
-       if (removed) {
-               add_page_to_lru_list(zone, page, page_lru(page));
-               SetPageLRU(page);
-       }
-       spin_unlock_irqrestore(&zone->lru_lock, flags);
-       return;
-}
-
 int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
                                gfp_t gfp_mask)
 {
@@ -2768,13 +2781,16 @@ static void
 __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *memcg,
                                        enum charge_type ctype)
 {
+       struct page_cgroup *pc;
+
        if (mem_cgroup_disabled())
                return;
        if (!memcg)
                return;
        cgroup_exclude_rmdir(&memcg->css);
 
-       __mem_cgroup_commit_charge_lrucare(page, memcg, ctype);
+       pc = lookup_page_cgroup(page);
+       __mem_cgroup_commit_charge(memcg, page, 1, pc, ctype, true);
        /*
         * Now swap is on-memory. This means this page may be
         * counted both as mem and swap....double count.
@@ -3026,23 +3042,6 @@ void mem_cgroup_uncharge_end(void)
        batch->memcg = NULL;
 }
 
-/*
- * A function for resetting pc->mem_cgroup for newly allocated pages.
- * This function should be called if the newpage will be added to LRU
- * before start accounting.
- */
-void mem_cgroup_reset_owner(struct page *newpage)
-{
-       struct page_cgroup *pc;
-
-       if (mem_cgroup_disabled())
-               return;
-
-       pc = lookup_page_cgroup(newpage);
-       VM_BUG_ON(PageCgroupUsed(pc));
-       pc->mem_cgroup = root_mem_cgroup;
-}
-
 #ifdef CONFIG_SWAP
 /*
  * called after __delete_from_swap_cache() and drop "page" account.
@@ -3247,7 +3246,7 @@ int mem_cgroup_prepare_migration(struct page *page,
                ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
        else
                ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
-       __mem_cgroup_commit_charge(memcg, newpage, 1, pc, ctype);
+       __mem_cgroup_commit_charge(memcg, newpage, 1, pc, ctype, false);
        return ret;
 }
 
@@ -3331,7 +3330,7 @@ void mem_cgroup_replace_page_cache(struct page *oldpage,
         * the newpage may be on LRU(or pagevec for LRU) already. We lock
         * LRU while we overwrite pc->mem_cgroup.
         */
-       __mem_cgroup_commit_charge_lrucare(newpage, memcg, type);
+       __mem_cgroup_commit_charge(memcg, newpage, 1, pc, type, true);
 }
 
 #ifdef CONFIG_DEBUG_VM
@@ -4413,6 +4412,9 @@ static void mem_cgroup_usage_unregister_event(struct cgroup *cgrp,
         */
        BUG_ON(!thresholds);
 
+       if (!thresholds->primary)
+               goto unlock;
+
        usage = mem_cgroup_usage(memcg, type == _MEMSWAP);
 
        /* Check if a threshold crossed before removing */
@@ -4461,7 +4463,7 @@ swap_buffers:
 
        /* To be sure that nobody uses thresholds */
        synchronize_rcu();
-
+unlock:
        mutex_unlock(&memcg->thresholds_lock);
 }
 
@@ -5073,7 +5075,7 @@ static struct page *mc_handle_present_pte(struct vm_area_struct *vma,
                return NULL;
        if (PageAnon(page)) {
                /* we don't move shared anon */
-               if (!move_anon() || page_mapcount(page) > 2)
+               if (!move_anon() || page_mapcount(page) > 1)
                        return NULL;
        } else if (!move_file())
                /* we ignore mapcount for file pages */