Merge branch 'akpm' (patches from Andrew)

Merge second patch-bomb from Andrew Morton:
 "Almost all of the rest of MM.  There was an unusually large amount of
  MM material this time"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (141 commits)
  zpool: remove no-op module init/exit
  mm: zbud: constify the zbud_ops
  mm: zpool: constify the zpool_ops
  mm: swap: zswap: maybe_preload & refactoring
  zram: unify error reporting
  zsmalloc: remove null check from destroy_handle_cache()
  zsmalloc: do not take class lock in zs_shrinker_count()
  zsmalloc: use class->pages_per_zspage
  zsmalloc: consider ZS_ALMOST_FULL as migrate source
  zsmalloc: partial page ordering within a fullness_list
  zsmalloc: use shrinker to trigger auto-compaction
  zsmalloc: account the number of compacted pages
  zsmalloc/zram: introduce zs_pool_stats api
  zsmalloc: cosmetic compaction code adjustments
  zsmalloc: introduce zs_can_compact() function
  zsmalloc: always keep per-class stats
  zsmalloc: drop unused variable `nr_to_migrate'
  mm/memblock.c: fix comment in __next_mem_range()
  mm/page_alloc.c: fix type information of memoryless node
  memory-hotplug: fix comments in zone_spanned_pages_in_node() and zone_spanned_pages_in_node()
  ...

mm/page_alloc.c

@@ -125,6 +125,24 @@ unsigned long dirty_balance_reserve __read_mostly;
 int percpu_pagelist_fraction;
 gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
 
+/*
+ * A cached value of the page's pageblock's migratetype, used when the page is
+ * put on a pcplist. Used to avoid the pageblock migratetype lookup when
+ * freeing from pcplists in most cases, at the cost of possibly becoming stale.
+ * Also the migratetype set in the page does not necessarily match the pcplist
+ * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
+ * other index - this ensures that it will be put on the correct CMA freelist.
+ */
+static inline int get_pcppage_migratetype(struct page *page)
+{
+	return page->index;
+}
+
+static inline void set_pcppage_migratetype(struct page *page, int migratetype)
+{
+	page->index = migratetype;
+}
+
 #ifdef CONFIG_PM_SLEEP
 /*
  * The following functions are used by the suspend/hibernate code to temporarily
@@ -791,7 +809,11 @@ static void free_pcppages_bulk(struct zone *zone, int count,
 			page = list_entry(list->prev, struct page, lru);
 			/* must delete as __free_one_page list manipulates */
 			list_del(&page->lru);
-			mt = get_freepage_migratetype(page);
+
+			mt = get_pcppage_migratetype(page);
+			/* MIGRATE_ISOLATE page should not go to pcplists */
+			VM_BUG_ON_PAGE(is_migrate_isolate(mt), page);
+			/* Pageblock could have been isolated meanwhile */
 			if (unlikely(has_isolate_pageblock(zone)))
 				mt = get_pageblock_migratetype(page);
 
@@ -955,7 +977,6 @@ static void __free_pages_ok(struct page *page, unsigned int order)
 	migratetype = get_pfnblock_migratetype(page, pfn);
 	local_irq_save(flags);
 	__count_vm_events(PGFREE, 1 << order);
-	set_freepage_migratetype(page, migratetype);
 	free_one_page(page_zone(page), page, pfn, order, migratetype);
 	local_irq_restore(flags);
 }
@@ -1383,7 +1404,7 @@ struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
 		rmv_page_order(page);
 		area->nr_free--;
 		expand(zone, page, order, current_order, area, migratetype);
-		set_freepage_migratetype(page, migratetype);
+		set_pcppage_migratetype(page, migratetype);
 		return page;
 	}
 
@@ -1460,7 +1481,6 @@ int move_freepages(struct zone *zone,
 		order = page_order(page);
 		list_move(&page->lru,
 			  &zone->free_area[order].free_list[migratetype]);
-		set_freepage_migratetype(page, migratetype);
 		page += 1 << order;
 		pages_moved += 1 << order;
 	}
@@ -1630,14 +1650,13 @@ __rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype)
 		expand(zone, page, order, current_order, area,
 					start_migratetype);
 		/*
-		 * The freepage_migratetype may differ from pageblock's
+		 * The pcppage_migratetype may differ from pageblock's
 		 * migratetype depending on the decisions in
-		 * try_to_steal_freepages(). This is OK as long as it
-		 * does not differ for MIGRATE_CMA pageblocks. For CMA
-		 * we need to make sure unallocated pages flushed from
-		 * pcp lists are returned to the correct freelist.
+		 * find_suitable_fallback(). This is OK as long as it does not
+		 * differ for MIGRATE_CMA pageblocks. Those can be used as
+		 * fallback only via special __rmqueue_cma_fallback() function
 		 */
-		set_freepage_migratetype(page, start_migratetype);
+		set_pcppage_migratetype(page, start_migratetype);
 
 		trace_mm_page_alloc_extfrag(page, order, current_order,
 			start_migratetype, fallback_mt);
@@ -1713,7 +1732,7 @@ static int rmqueue_bulk(struct zone *zone, unsigned int order,
 		else
 			list_add_tail(&page->lru, list);
 		list = &page->lru;
-		if (is_migrate_cma(get_freepage_migratetype(page)))
+		if (is_migrate_cma(get_pcppage_migratetype(page)))
 			__mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
 					      -(1 << order));
 	}
@@ -1910,7 +1929,7 @@ void free_hot_cold_page(struct page *page, bool cold)
 		return;
 
 	migratetype = get_pfnblock_migratetype(page, pfn);
-	set_freepage_migratetype(page, migratetype);
+	set_pcppage_migratetype(page, migratetype);
 	local_irq_save(flags);
 	__count_vm_event(PGFREE);
 
@@ -2115,7 +2134,7 @@ struct page *buffered_rmqueue(struct zone *preferred_zone,
 		if (!page)
 			goto failed;
 		__mod_zone_freepage_state(zone, -(1 << order),
-					  get_freepage_migratetype(page));
+					  get_pcppage_migratetype(page));
 	}
 
 	__mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order));
@@ -2696,6 +2715,12 @@ static inline struct page *
 __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
 	const struct alloc_context *ac, unsigned long *did_some_progress)
 {
+	struct oom_control oc = {
+		.zonelist = ac->zonelist,
+		.nodemask = ac->nodemask,
+		.gfp_mask = gfp_mask,
+		.order = order,
+	};
 	struct page *page;
 
 	*did_some_progress = 0;
@@ -2747,8 +2772,7 @@ __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
 			goto out;
 	}
 	/* Exhausted what can be done so it's blamo time */
-	if (out_of_memory(ac->zonelist, gfp_mask, order, ac->nodemask, false)
-			|| WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL))
+	if (out_of_memory(&oc) || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL))
 		*did_some_progress = 1;
 out:
 	mutex_unlock(&oom_lock);
@@ -3490,8 +3514,6 @@ EXPORT_SYMBOL(alloc_pages_exact);
  *
  * Like alloc_pages_exact(), but try to allocate on node nid first before falling
  * back.
- * Note this is not alloc_pages_exact_node() which allocates on a specific node,
- * but is not exact.
  */
 void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
 {
@@ -5066,7 +5088,7 @@ static unsigned long __meminit zone_spanned_pages_in_node(int nid,
 {
 	unsigned long zone_start_pfn, zone_end_pfn;
 
-	/* When hotadd a new node, the node should be empty */
+	/* When hotadd a new node from cpu_up(), the node should be empty */
 	if (!node_start_pfn && !node_end_pfn)
 		return 0;
 
@@ -5133,7 +5155,7 @@ static unsigned long __meminit zone_absent_pages_in_node(int nid,
 	unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type];
 	unsigned long zone_start_pfn, zone_end_pfn;
 
-	/* When hotadd a new node, the node should be empty */
+	/* When hotadd a new node from cpu_up(), the node should be empty */
 	if (!node_start_pfn && !node_end_pfn)
 		return 0;
 
@@ -5306,8 +5328,7 @@ static unsigned long __paginginit calc_memmap_size(unsigned long spanned_pages,
  *
  * NOTE: pgdat should get zeroed by caller.
  */
-static void __paginginit free_area_init_core(struct pglist_data *pgdat,
-		unsigned long node_start_pfn, unsigned long node_end_pfn)
+static void __paginginit free_area_init_core(struct pglist_data *pgdat)
 {
 	enum zone_type j;
 	int nid = pgdat->node_id;
@@ -5458,7 +5479,8 @@ void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
 	get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
 	pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,
-		(u64)start_pfn << PAGE_SHIFT, ((u64)end_pfn << PAGE_SHIFT) - 1);
+		(u64)start_pfn << PAGE_SHIFT,
+		end_pfn ? ((u64)end_pfn << PAGE_SHIFT) - 1 : 0);
 #endif
 	calculate_node_totalpages(pgdat, start_pfn, end_pfn,
 				  zones_size, zholes_size);
@@ -5470,7 +5492,7 @@ void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
 		(unsigned long)pgdat->node_mem_map);
 #endif
 
-	free_area_init_core(pgdat, start_pfn, end_pfn);
+	free_area_init_core(pgdat);
 }
 
 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
@@ -5481,11 +5503,9 @@ void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
  */
 void __init setup_nr_node_ids(void)
 {
-	unsigned int node;
-	unsigned int highest = 0;
+	unsigned int highest;
 
-	for_each_node_mask(node, node_possible_map)
-		highest = node;
+	highest = find_last_bit(node_possible_map.bits, MAX_NUMNODES);
 	nr_node_ids = highest + 1;
 }
 #endif
@@ -6006,7 +6026,7 @@ void __init mem_init_print_info(const char *str)
  * set_dma_reserve - set the specified number of pages reserved in the first zone
  * @new_dma_reserve: The number of pages to mark reserved
  *
- * The per-cpu batchsize and zone watermarks are determined by present_pages.
+ * The per-cpu batchsize and zone watermarks are determined by managed_pages.
  * In the DMA zone, a significant percentage may be consumed by kernel image
  * and other unfreeable allocations which can skew the watermarks badly. This
  * function may optionally be used to account for unfreeable pages in the
@@ -6059,7 +6079,7 @@ void __init page_alloc_init(void)
 }
 
 /*
- * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
+ * calculate_totalreserve_pages - called when sysctl_lowmem_reserve_ratio
  *	or min_free_kbytes changes.
  */
 static void calculate_totalreserve_pages(void)
@@ -6103,7 +6123,7 @@ static void calculate_totalreserve_pages(void)
 
 /*
  * setup_per_zone_lowmem_reserve - called whenever
- *	sysctl_lower_zone_reserve_ratio changes.  Ensures that each zone
+ *	sysctl_lowmem_reserve_ratio changes.  Ensures that each zone
  *	has a correct pages reserved value, so an adequate number of
  *	pages are left in the zone after a successful __alloc_pages().
  */