1 files changed, 15 insertions, 129 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index ca46080bb074..546d02ce90ee 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -58,9 +58,6 @@
  * RECLAIM_MODE_SINGLE: Reclaim only order-0 pages
  * RECLAIM_MODE_ASYNC:  Do not block
  * RECLAIM_MODE_SYNC:   Allow blocking e.g. call wait_on_page_writeback
- * RECLAIM_MODE_LUMPYRECLAIM: For high-order allocations, take a reference
- *			page from the LRU and reclaim all pages within a
- *			naturally aligned range
  * RECLAIM_MODE_COMPACTION: For high-order allocations, reclaim a number of
  *			order-0 pages and then compact the zone
  */
@@ -68,7 +65,6 @@ typedef unsigned __bitwise__ reclaim_mode_t;
 #define RECLAIM_MODE_SINGLE		((__force reclaim_mode_t)0x01u)
 #define RECLAIM_MODE_ASYNC		((__force reclaim_mode_t)0x02u)
 #define RECLAIM_MODE_SYNC		((__force reclaim_mode_t)0x04u)
-#define RECLAIM_MODE_LUMPYRECLAIM	((__force reclaim_mode_t)0x08u)
 #define RECLAIM_MODE_COMPACTION		((__force reclaim_mode_t)0x10u)
 
 struct scan_control {
@@ -367,27 +363,17 @@ out:
 static void set_reclaim_mode(int priority, struct scan_control *sc,
 				   bool sync)
 {
+	/* Sync reclaim used only for compaction */
 	reclaim_mode_t syncmode = sync ? RECLAIM_MODE_SYNC : RECLAIM_MODE_ASYNC;
 
 	/*
-	 * Initially assume we are entering either lumpy reclaim or
-	 * reclaim/compaction.Depending on the order, we will either set the
-	 * sync mode or just reclaim order-0 pages later.
-	 */
-	if (COMPACTION_BUILD)
-		sc->reclaim_mode = RECLAIM_MODE_COMPACTION;
-	else
-		sc->reclaim_mode = RECLAIM_MODE_LUMPYRECLAIM;
-
-	/*
-	 * Avoid using lumpy reclaim or reclaim/compaction if possible by
-	 * restricting when its set to either costly allocations or when
+	 * Restrict reclaim/compaction to costly allocations or when
 	 * under memory pressure
 	 */
-	if (sc->order > PAGE_ALLOC_COSTLY_ORDER)
-		sc->reclaim_mode |= syncmode;
-	else if (sc->order && priority < DEF_PRIORITY - 2)
-		sc->reclaim_mode |= syncmode;
+	if (COMPACTION_BUILD && sc->order &&
+			(sc->order > PAGE_ALLOC_COSTLY_ORDER ||
+			 priority < DEF_PRIORITY - 2))
+		sc->reclaim_mode = RECLAIM_MODE_COMPACTION | syncmode;
 	else
 		sc->reclaim_mode = RECLAIM_MODE_SINGLE | RECLAIM_MODE_ASYNC;
 }
@@ -416,10 +402,6 @@ static int may_write_to_queue(struct backing_dev_info *bdi,
 		return 1;
 	if (bdi == current->backing_dev_info)
 		return 1;
-
-	/* lumpy reclaim for hugepage often need a lot of write */
-	if (sc->order > PAGE_ALLOC_COSTLY_ORDER)
-		return 1;
 	return 0;
 }
 
@@ -710,10 +692,6 @@ static enum page_references page_check_references(struct page *page,
 	referenced_ptes = page_referenced(page, 1, mz->mem_cgroup, &vm_flags);
 	referenced_page = TestClearPageReferenced(page);
 
-	/* Lumpy reclaim - ignore references */
-	if (sc->reclaim_mode & RECLAIM_MODE_LUMPYRECLAIM)
-		return PAGEREF_RECLAIM;
-
 	/*
 	 * Mlock lost the isolation race with us.  Let try_to_unmap()
 	 * move the page to the unevictable list.
@@ -824,7 +802,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 				wait_on_page_writeback(page);
 			else {
 				unlock_page(page);
-				goto keep_lumpy;
+				goto keep_reclaim_mode;
 			}
 		}
 
@@ -908,7 +886,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 				goto activate_locked;
 			case PAGE_SUCCESS:
 				if (PageWriteback(page))
-					goto keep_lumpy;
+					goto keep_reclaim_mode;
 				if (PageDirty(page))
 					goto keep;
 
@@ -1008,7 +986,7 @@ keep_locked:
 		unlock_page(page);
 keep:
 		reset_reclaim_mode(sc);
-keep_lumpy:
+keep_reclaim_mode:
 		list_add(&page->lru, &ret_pages);
 		VM_BUG_ON(PageLRU(page) || PageUnevictable(page));
 	}
@@ -1064,11 +1042,7 @@ int __isolate_lru_page(struct page *page, isolate_mode_t mode, int file)
 	if (!all_lru_mode && !!page_is_file_cache(page) != file)
 		return ret;
 
-	/*
-	 * When this function is being called for lumpy reclaim, we
-	 * initially look into all LRU pages, active, inactive and
-	 * unevictable; only give shrink_page_list evictable pages.
-	 */
+	/* Do not give back unevictable pages for compaction */
 	if (PageUnevictable(page))
 		return ret;
 
@@ -1153,9 +1127,6 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
 	struct lruvec *lruvec;
 	struct list_head *src;
 	unsigned long nr_taken = 0;
-	unsigned long nr_lumpy_taken = 0;
-	unsigned long nr_lumpy_dirty = 0;
-	unsigned long nr_lumpy_failed = 0;
 	unsigned long scan;
 	int lru = LRU_BASE;
 
@@ -1168,10 +1139,6 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
 
 	for (scan = 0; scan < nr_to_scan && !list_empty(src); scan++) {
 		struct page *page;
-		unsigned long pfn;
-		unsigned long end_pfn;
-		unsigned long page_pfn;
-		int zone_id;
 
 		page = lru_to_page(src);
 		prefetchw_prev_lru_page(page, src, flags);
@@ -1193,84 +1160,6 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
 		default:
 			BUG();
 		}
-
-		if (!sc->order || !(sc->reclaim_mode & RECLAIM_MODE_LUMPYRECLAIM))
-			continue;
-
-		/*
-		 * Attempt to take all pages in the order aligned region
-		 * surrounding the tag page.  Only take those pages of
-		 * the same active state as that tag page.  We may safely
-		 * round the target page pfn down to the requested order
-		 * as the mem_map is guaranteed valid out to MAX_ORDER,
-		 * where that page is in a different zone we will detect
-		 * it from its zone id and abort this block scan.
-		 */
-		zone_id = page_zone_id(page);
-		page_pfn = page_to_pfn(page);
-		pfn = page_pfn & ~((1 << sc->order) - 1);
-		end_pfn = pfn + (1 << sc->order);
-		for (; pfn < end_pfn; pfn++) {
-			struct page *cursor_page;
-
-			/* The target page is in the block, ignore it. */
-			if (unlikely(pfn == page_pfn))
-				continue;
-
-			/* Avoid holes within the zone. */
-			if (unlikely(!pfn_valid_within(pfn)))
-				break;
-
-			cursor_page = pfn_to_page(pfn);
-
-			/* Check that we have not crossed a zone boundary. */
-			if (unlikely(page_zone_id(cursor_page) != zone_id))
-				break;
-
-			/*
-			 * If we don't have enough swap space, reclaiming of
-			 * anon page which don't already have a swap slot is
-			 * pointless.
-			 */
-			if (nr_swap_pages <= 0 && PageSwapBacked(cursor_page) &&
-			    !PageSwapCache(cursor_page))
-				break;
-
-			if (__isolate_lru_page(cursor_page, mode, file) == 0) {
-				unsigned int isolated_pages;
-
-				mem_cgroup_lru_del(cursor_page);
-				list_move(&cursor_page->lru, dst);
-				isolated_pages = hpage_nr_pages(cursor_page);
-				nr_taken += isolated_pages;
-				nr_lumpy_taken += isolated_pages;
-				if (PageDirty(cursor_page))
-					nr_lumpy_dirty += isolated_pages;
-				scan++;
-				pfn += isolated_pages - 1;
-			} else {
-				/*
-				 * Check if the page is freed already.
-				 *
-				 * We can't use page_count() as that
-				 * requires compound_head and we don't
-				 * have a pin on the page here. If a
-				 * page is tail, we may or may not
-				 * have isolated the head, so assume
-				 * it's not free, it'd be tricky to
-				 * track the head status without a
-				 * page pin.
-				 */
-				if (!PageTail(cursor_page) &&
-				    !atomic_read(&cursor_page->_count))
-					continue;
-				break;
-			}
-		}
-
-		/* If we break out of the loop above, lumpy reclaim failed */
-		if (pfn < end_pfn)
-			nr_lumpy_failed++;
 	}
 
 	*nr_scanned = scan;
@@ -1278,7 +1167,6 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
 	trace_mm_vmscan_lru_isolate(sc->order,
 			nr_to_scan, scan,
 			nr_taken,
-			nr_lumpy_taken, nr_lumpy_dirty, nr_lumpy_failed,
 			mode, file);
 	return nr_taken;
 }
@@ -1466,13 +1354,13 @@ static inline bool should_reclaim_stall(unsigned long nr_taken,
 					int priority,
 					struct scan_control *sc)
 {
-	int lumpy_stall_priority;
+	int stall_priority;
 
 	/* kswapd should not stall on sync IO */
 	if (current_is_kswapd())
 		return false;
 
-	/* Only stall on lumpy reclaim */
+	/* Only stall for memory compaction */
 	if (sc->reclaim_mode & RECLAIM_MODE_SINGLE)
 		return false;
 
@@ -1487,11 +1375,11 @@ static inline bool should_reclaim_stall(unsigned long nr_taken,
 	 * priority to be much higher before stalling.
 	 */
 	if (sc->order > PAGE_ALLOC_COSTLY_ORDER)
-		lumpy_stall_priority = DEF_PRIORITY;
+		stall_priority = DEF_PRIORITY;
 	else
-		lumpy_stall_priority = DEF_PRIORITY / 3;
+		stall_priority = DEF_PRIORITY / 3;
 
-	return priority <= lumpy_stall_priority;
+	return priority <= stall_priority;
 }
 
 /*
@@ -1523,8 +1411,6 @@ shrink_inactive_list(unsigned long nr_to_scan, struct mem_cgroup_zone *mz,
 	}
 
 	set_reclaim_mode(priority, sc, false);
-	if (sc->reclaim_mode & RECLAIM_MODE_LUMPYRECLAIM)
-		isolate_mode |= ISOLATE_ACTIVE;
 
 	lru_add_drain();