Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:
 "More MM work: a memcg scalability improvememt"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm/lru: revise the comments of lru_lock
  mm/lru: introduce relock_page_lruvec()
  mm/lru: replace pgdat lru_lock with lruvec lock
  mm/swap.c: serialize memcg changes in pagevec_lru_move_fn
  mm/compaction: do page isolation first in compaction
  mm/lru: introduce TestClearPageLRU()
  mm/mlock: remove __munlock_isolate_lru_page()
  mm/mlock: remove lru_lock on TestClearPageMlocked
  mm/vmscan: remove lruvec reget in move_pages_to_lru
  mm/lru: move lock into lru_note_cost
  mm/swap.c: fold vm event PGROTATED into pagevec_move_tail_fn
  mm/memcg: add debug checking in lock_page_memcg
  mm: page_idle_get_page() does not need lru_lock
  mm/rmap: stop store reordering issue on page->mapping
  mm/vmscan: remove unnecessary lruvec adding
  mm/thp: narrow lru locking
  mm/thp: simplify lru_add_page_tail()
  mm/thp: use head for head page in lru_add_page_tail()
  mm/thp: move lru_add_page_tail() to huge_memory.c

1 files changed, 17 insertions, 46 deletions

diff --git a/mm/mlock.c b/mm/mlock.c
index 884b1216da6a6..55b3b3672977b 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -106,26 +106,6 @@ void mlock_vma_page(struct page *page)
 }
 
 /*
- * Isolate a page from LRU with optional get_page() pin.
- * Assumes lru_lock already held and page already pinned.
- */
-static bool __munlock_isolate_lru_page(struct page *page, bool getpage)
-{
-	if (PageLRU(page)) {
-		struct lruvec *lruvec;
-
-		lruvec = mem_cgroup_page_lruvec(page, page_pgdat(page));
-		if (getpage)
-			get_page(page);
-		ClearPageLRU(page);
-		del_page_from_lru_list(page, lruvec, page_lru(page));
-		return true;
-	}
-
-	return false;
-}
-
-/*
  * Finish munlock after successful page isolation
  *
  * Page must be locked. This is a wrapper for try_to_munlock()
@@ -187,40 +167,24 @@ static void __munlock_isolation_failed(struct page *page)
 unsigned int munlock_vma_page(struct page *page)
 {
 	int nr_pages;
-	pg_data_t *pgdat = page_pgdat(page);
 
 	/* For try_to_munlock() and to serialize with page migration */
 	BUG_ON(!PageLocked(page));
-
 	VM_BUG_ON_PAGE(PageTail(page), page);
 
-	/*
-	 * Serialize with any parallel __split_huge_page_refcount() which
-	 * might otherwise copy PageMlocked to part of the tail pages before
-	 * we clear it in the head page. It also stabilizes thp_nr_pages().
-	 */
-	spin_lock_irq(&pgdat->lru_lock);
-
 	if (!TestClearPageMlocked(page)) {
 		/* Potentially, PTE-mapped THP: do not skip the rest PTEs */
-		nr_pages = 1;
-		goto unlock_out;
+		return 0;
 	}
 
 	nr_pages = thp_nr_pages(page);
-	__mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages);
+	mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages);
 
-	if (__munlock_isolate_lru_page(page, true)) {
-		spin_unlock_irq(&pgdat->lru_lock);
+	if (!isolate_lru_page(page))
 		__munlock_isolated_page(page);
-		goto out;
-	}
-	__munlock_isolation_failed(page);
-
-unlock_out:
-	spin_unlock_irq(&pgdat->lru_lock);
+	else
+		__munlock_isolation_failed(page);
 
-out:
 	return nr_pages - 1;
 }
 
@@ -298,12 +262,12 @@ static void __munlock_pagevec(struct pagevec *pvec, struct zone *zone)
 	int nr = pagevec_count(pvec);
 	int delta_munlocked = -nr;
 	struct pagevec pvec_putback;
+	struct lruvec *lruvec = NULL;
 	int pgrescued = 0;
 
 	pagevec_init(&pvec_putback);
 
 	/* Phase 1: page isolation */
-	spin_lock_irq(&zone->zone_pgdat->lru_lock);
 	for (i = 0; i < nr; i++) {
 		struct page *page = pvec->pages[i];
 
@@ -312,9 +276,12 @@ static void __munlock_pagevec(struct pagevec *pvec, struct zone *zone)
 			 * We already have pin from follow_page_mask()
 			 * so we can spare the get_page() here.
 			 */
-			if (__munlock_isolate_lru_page(page, false))
+			if (TestClearPageLRU(page)) {
+				lruvec = relock_page_lruvec_irq(page, lruvec);
+				del_page_from_lru_list(page, lruvec,
+							page_lru(page));
 				continue;
-			else
+			} else
 				__munlock_isolation_failed(page);
 		} else {
 			delta_munlocked++;
@@ -329,8 +296,12 @@ static void __munlock_pagevec(struct pagevec *pvec, struct zone *zone)
 		pagevec_add(&pvec_putback, pvec->pages[i]);
 		pvec->pages[i] = NULL;
 	}
-	__mod_zone_page_state(zone, NR_MLOCK, delta_munlocked);
-	spin_unlock_irq(&zone->zone_pgdat->lru_lock);
+	if (lruvec) {
+		__mod_zone_page_state(zone, NR_MLOCK, delta_munlocked);
+		unlock_page_lruvec_irq(lruvec);
+	} else if (delta_munlocked) {
+		mod_zone_page_state(zone, NR_MLOCK, delta_munlocked);
+	}
 
 	/* Now we can release pins of pages that we are not munlocking */
 	pagevec_release(&pvec_putback);