1 files changed, 158 insertions, 122 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index f3d603cef2c0..f9e450c6b6e4 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -65,6 +65,7 @@
 #include <linux/page_owner.h>
 #include <linux/kthread.h>
 #include <linux/memcontrol.h>
+#include <linux/ftrace.h>
 
 #include <asm/sections.h>
 #include <asm/tlbflush.h>
@@ -1090,14 +1091,10 @@ static void free_pcppages_bulk(struct zone *zone, int count,
 {
         int migratetype = 0;
         int batch_free = 0;
-        unsigned long nr_scanned, flags;
         bool isolated_pageblocks;
 
-        spin_lock_irqsave(&zone->lock, flags);
+        spin_lock(&zone->lock);
         isolated_pageblocks = has_isolate_pageblock(zone);
-        nr_scanned = node_page_state(zone->zone_pgdat, NR_PAGES_SCANNED);
-        if (nr_scanned)
-                __mod_node_page_state(zone->zone_pgdat, NR_PAGES_SCANNED, -nr_scanned);
 
         while (count) {
                 struct page *page;
@@ -1142,7 +1139,7 @@ static void free_pcppages_bulk(struct zone *zone, int count,
                         trace_mm_page_pcpu_drain(page, 0, mt);
                 } while (--count && --batch_free && !list_empty(list));
         }
-        spin_unlock_irqrestore(&zone->lock, flags);
+        spin_unlock(&zone->lock);
 }
 
 static void free_one_page(struct zone *zone,
@@ -1150,19 +1147,13 @@ static void free_one_page(struct zone *zone,
                                 unsigned int order,
                                 int migratetype)
 {
-        unsigned long nr_scanned, flags;
-        spin_lock_irqsave(&zone->lock, flags);
-        __count_vm_events(PGFREE, 1 << order);
-        nr_scanned = node_page_state(zone->zone_pgdat, NR_PAGES_SCANNED);
-        if (nr_scanned)
-                __mod_node_page_state(zone->zone_pgdat, NR_PAGES_SCANNED, -nr_scanned);
-
+        spin_lock(&zone->lock);
         if (unlikely(has_isolate_pageblock(zone) ||
                 is_migrate_isolate(migratetype))) {
                 migratetype = get_pfnblock_migratetype(page, pfn);
         }
         __free_one_page(page, pfn, zone, order, migratetype);
-        spin_unlock_irqrestore(&zone->lock, flags);
+        spin_unlock(&zone->lock);
 }
 
 static void __meminit __init_single_page(struct page *page, unsigned long pfn,
@@ -1240,6 +1231,7 @@ void __meminit reserve_bootmem_region(phys_addr_t start, phys_addr_t end)
 
 static void __free_pages_ok(struct page *page, unsigned int order)
 {
+        unsigned long flags;
         int migratetype;
         unsigned long pfn = page_to_pfn(page);
 
@@ -1247,7 +1239,10 @@ static void __free_pages_ok(struct page *page, unsigned int order)
                 return;
 
         migratetype = get_pfnblock_migratetype(page, pfn);
+        local_irq_save(flags);
+        __count_vm_events(PGFREE, 1 << order);
         free_one_page(page_zone(page), page, pfn, order, migratetype);
+        local_irq_restore(flags);
 }
 
 static void __init __free_pages_boot_core(struct page *page, unsigned int order)
@@ -1695,10 +1690,10 @@ static inline int check_new_page(struct page *page)
         return 1;
 }
 
-static inline bool free_pages_prezeroed(bool poisoned)
+static inline bool free_pages_prezeroed(void)
 {
         return IS_ENABLED(CONFIG_PAGE_POISONING_ZERO) &&
-                page_poisoning_enabled() && poisoned;
+                page_poisoning_enabled();
 }
 
 #ifdef CONFIG_DEBUG_VM
@@ -1752,17 +1747,10 @@ static void prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags
                                                         unsigned int alloc_flags)
 {
         int i;
-        bool poisoned = true;
-
-        for (i = 0; i < (1 << order); i++) {
-                struct page *p = page + i;
-                if (poisoned)
-                        poisoned &= page_is_poisoned(p);
-        }
 
         post_alloc_hook(page, order, gfp_flags);
 
-        if (!free_pages_prezeroed(poisoned) && (gfp_flags & __GFP_ZERO))
+        if (!free_pages_prezeroed() && (gfp_flags & __GFP_ZERO))
                 for (i = 0; i < (1 << order); i++)
                         clear_highpage(page + i);
 
@@ -1844,9 +1832,9 @@ static inline struct page *__rmqueue_cma_fallback(struct zone *zone,
  * Note that start_page and end_pages are not aligned on a pageblock
  * boundary. If alignment is required, use move_freepages_block()
  */
-int move_freepages(struct zone *zone,
+static int move_freepages(struct zone *zone,
                           struct page *start_page, struct page *end_page,
-                          int migratetype)
+                          int migratetype, int *num_movable)
 {
         struct page *page;
         unsigned int order;
@@ -1863,6 +1851,9 @@ int move_freepages(struct zone *zone,
         VM_BUG_ON(page_zone(start_page) != page_zone(end_page));
 #endif
 
+        if (num_movable)
+                *num_movable = 0;
+
         for (page = start_page; page <= end_page;) {
                 if (!pfn_valid_within(page_to_pfn(page))) {
                         page++;
@@ -1873,6 +1864,15 @@ int move_freepages(struct zone *zone,
                 VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page);
 
                 if (!PageBuddy(page)) {
+                        /*
+                         * We assume that pages that could be isolated for
+                         * migration are movable. But we don't actually try
+                         * isolating, as that would be expensive.
+                         */
+                        if (num_movable &&
+                                        (PageLRU(page) || __PageMovable(page)))
+                                (*num_movable)++;
+
                         page++;
                         continue;
                 }
@@ -1888,7 +1888,7 @@ int move_freepages(struct zone *zone,
 }
 
 int move_freepages_block(struct zone *zone, struct page *page,
-                                int migratetype)
+                                int migratetype, int *num_movable)
 {
         unsigned long start_pfn, end_pfn;
         struct page *start_page, *end_page;
@@ -1905,7 +1905,8 @@ int move_freepages_block(struct zone *zone, struct page *page,
         if (!zone_spans_pfn(zone, end_pfn))
                 return 0;
 
-        return move_freepages(zone, start_page, end_page, migratetype);
+        return move_freepages(zone, start_page, end_page, migratetype,
+                                                                num_movable);
 }
 
 static void change_pageblock_range(struct page *pageblock_page,
@@ -1955,28 +1956,79 @@ static bool can_steal_fallback(unsigned int order, int start_mt)
 /*
  * This function implements actual steal behaviour. If order is large enough,
  * we can steal whole pageblock. If not, we first move freepages in this
- * pageblock and check whether half of pages are moved or not. If half of
- * pages are moved, we can change migratetype of pageblock and permanently
- * use it's pages as requested migratetype in the future.
+ * pageblock to our migratetype and determine how many already-allocated pages
+ * are there in the pageblock with a compatible migratetype. If at least half
+ * of pages are free or compatible, we can change migratetype of the pageblock
+ * itself, so pages freed in the future will be put on the correct free list.
  */
 static void steal_suitable_fallback(struct zone *zone, struct page *page,
-                                                          int start_type)
+                                        int start_type, bool whole_block)
 {
         unsigned int current_order = page_order(page);
-        int pages;
+        struct free_area *area;
+        int free_pages, movable_pages, alike_pages;
+        int old_block_type;
+
+        old_block_type = get_pageblock_migratetype(page);
+
+        /*
+         * This can happen due to races and we want to prevent broken
+         * highatomic accounting.
+         */
+        if (is_migrate_highatomic(old_block_type))
+                goto single_page;
 
         /* Take ownership for orders >= pageblock_order */
         if (current_order >= pageblock_order) {
                 change_pageblock_range(page, current_order, start_type);
-                return;
+                goto single_page;
+        }
+
+        /* We are not allowed to try stealing from the whole block */
+        if (!whole_block)
+                goto single_page;
+
+        free_pages = move_freepages_block(zone, page, start_type,
+                                                &movable_pages);
+        /*
+         * Determine how many pages are compatible with our allocation.
+         * For movable allocation, it's the number of movable pages which
+         * we just obtained. For other types it's a bit more tricky.
+         */
+        if (start_type == MIGRATE_MOVABLE) {
+                alike_pages = movable_pages;
+        } else {
+                /*
+                 * If we are falling back a RECLAIMABLE or UNMOVABLE allocation
+                 * to MOVABLE pageblock, consider all non-movable pages as
+                 * compatible. If it's UNMOVABLE falling back to RECLAIMABLE or
+                 * vice versa, be conservative since we can't distinguish the
+                 * exact migratetype of non-movable pages.
+                 */
+                if (old_block_type == MIGRATE_MOVABLE)
+                        alike_pages = pageblock_nr_pages
+                                                - (free_pages + movable_pages);
+                else
+                        alike_pages = 0;
         }
 
-        pages = move_freepages_block(zone, page, start_type);
+        /* moving whole block can fail due to zone boundary conditions */
+        if (!free_pages)
+                goto single_page;
 
-        /* Claim the whole block if over half of it is free */
-        if (pages >= (1 << (pageblock_order-1)) ||
+        /*
+         * If a sufficient number of pages in the block are either free or of
+         * comparable migratability as our allocation, claim the whole block.
+         */
+        if (free_pages + alike_pages >= (1 << (pageblock_order-1)) ||
                         page_group_by_mobility_disabled)
                 set_pageblock_migratetype(page, start_type);
+
+        return;
+
+single_page:
+        area = &zone->free_area[current_order];
+        list_move(&page->lru, &area->free_list[start_type]);
 }
 
 /*
@@ -2042,11 +2094,11 @@ static void reserve_highatomic_pageblock(struct page *page, struct zone *zone,
 
         /* Yoink! */
         mt = get_pageblock_migratetype(page);
-        if (mt != MIGRATE_HIGHATOMIC &&
-                        !is_migrate_isolate(mt) && !is_migrate_cma(mt)) {
+        if (!is_migrate_highatomic(mt) && !is_migrate_isolate(mt)
+            && !is_migrate_cma(mt)) {
                 zone->nr_reserved_highatomic += pageblock_nr_pages;
                 set_pageblock_migratetype(page, MIGRATE_HIGHATOMIC);
-                move_freepages_block(zone, page, MIGRATE_HIGHATOMIC);
+                move_freepages_block(zone, page, MIGRATE_HIGHATOMIC, NULL);
         }
 
 out_unlock:
@@ -2100,8 +2152,7 @@ static bool unreserve_highatomic_pageblock(const struct alloc_context *ac,
                          * from highatomic to ac->migratetype. So we should
                          * adjust the count once.
                          */
-                        if (get_pageblock_migratetype(page) ==
-                                                        MIGRATE_HIGHATOMIC) {
+                        if (is_migrate_highatomic_page(page)) {
                                 /*
                                  * It should never happen but changes to
                                  * locking could inadvertently allow a per-cpu
@@ -2124,7 +2175,8 @@ static bool unreserve_highatomic_pageblock(const struct alloc_context *ac,
                          * may increase.
                          */
                         set_pageblock_migratetype(page, ac->migratetype);
-                        ret = move_freepages_block(zone, page, ac->migratetype);
+                        ret = move_freepages_block(zone, page, ac->migratetype,
+                                                                        NULL);
                         if (ret) {
                                 spin_unlock_irqrestore(&zone->lock, flags);
                                 return ret;
@@ -2136,8 +2188,13 @@ static bool unreserve_highatomic_pageblock(const struct alloc_context *ac,
         return false;
 }
 
-/* Remove an element from the buddy allocator from the fallback list */
-static inline struct page *
+/*
+ * Try finding a free buddy page on the fallback list and put it on the free
+ * list of requested migratetype, possibly along with other pages from the same
+ * block, depending on fragmentation avoidance heuristics. Returns true if
+ * fallback was found so that __rmqueue_smallest() can grab it.
+ */
+static inline bool
 __rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype)
 {
         struct free_area *area;
@@ -2158,33 +2215,17 @@ __rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype)
 
                 page = list_first_entry(&area->free_list[fallback_mt],
                                                 struct page, lru);
-                if (can_steal &&
-                        get_pageblock_migratetype(page) != MIGRATE_HIGHATOMIC)
-                        steal_suitable_fallback(zone, page, start_migratetype);
-
-                /* Remove the page from the freelists */
-                area->nr_free--;
-                list_del(&page->lru);
-                rmv_page_order(page);
 
-                expand(zone, page, order, current_order, area,
-                                        start_migratetype);
-                /*
-                 * The pcppage_migratetype may differ from pageblock's
-                 * migratetype depending on the decisions in
-                 * 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_pcppage_migratetype(page, start_migratetype);
+                steal_suitable_fallback(zone, page, start_migratetype,
+                                                                can_steal);
 
                 trace_mm_page_alloc_extfrag(page, order, current_order,
                         start_migratetype, fallback_mt);
 
-                return page;
+                return true;
         }
 
-        return NULL;
+        return false;
 }
 
 /*
@@ -2196,13 +2237,14 @@ static struct page *__rmqueue(struct zone *zone, unsigned int order,
 {
         struct page *page;
 
+retry:
         page = __rmqueue_smallest(zone, order, migratetype);
         if (unlikely(!page)) {
                 if (migratetype == MIGRATE_MOVABLE)
                         page = __rmqueue_cma_fallback(zone, order);
 
-                if (!page)
-                        page = __rmqueue_fallback(zone, order, migratetype);
+                if (!page && __rmqueue_fallback(zone, order, migratetype))
+                        goto retry;
         }
 
         trace_mm_page_alloc_zone_locked(page, order, migratetype);
@@ -2219,9 +2261,8 @@ static int rmqueue_bulk(struct zone *zone, unsigned int order,
                         int migratetype, bool cold)
 {
         int i, alloced = 0;
-        unsigned long flags;
 
-        spin_lock_irqsave(&zone->lock, flags);
+        spin_lock(&zone->lock);
         for (i = 0; i < count; ++i) {
                 struct page *page = __rmqueue(zone, order, migratetype);
                 if (unlikely(page == NULL))
@@ -2257,7 +2298,7 @@ static int rmqueue_bulk(struct zone *zone, unsigned int order,
          * pages added to the pcp list.
          */
         __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
-        spin_unlock_irqrestore(&zone->lock, flags);
+        spin_unlock(&zone->lock);
         return alloced;
 }
 
@@ -2485,25 +2526,22 @@ void free_hot_cold_page(struct page *page, bool cold)
 {
         struct zone *zone = page_zone(page);
         struct per_cpu_pages *pcp;
+        unsigned long flags;
         unsigned long pfn = page_to_pfn(page);
         int migratetype;
 
-        if (in_interrupt()) {
-                __free_pages_ok(page, 0);
-                return;
-        }
-
         if (!free_pcp_prepare(page))
                 return;
 
         migratetype = get_pfnblock_migratetype(page, pfn);
         set_pcppage_migratetype(page, migratetype);
-        preempt_disable();
+        local_irq_save(flags);
+        __count_vm_event(PGFREE);
 
         /*
          * We only track unmovable, reclaimable and movable on pcp lists.
          * Free ISOLATE pages back to the allocator because they are being
-         * offlined but treat RESERVE as movable pages so we can get those
+         * offlined but treat HIGHATOMIC as movable pages so we can get those
          * areas back if necessary. Otherwise, we may have to free
          * excessively into the page allocator
          */
@@ -2515,7 +2553,6 @@ void free_hot_cold_page(struct page *page, bool cold)
                 migratetype = MIGRATE_MOVABLE;
         }
 
-        __count_vm_event(PGFREE);
         pcp = &this_cpu_ptr(zone->pageset)->pcp;
         if (!cold)
                 list_add(&page->lru, &pcp->lists[migratetype]);
@@ -2529,7 +2566,7 @@ void free_hot_cold_page(struct page *page, bool cold)
         }
 
 out:
-        preempt_enable();
+        local_irq_restore(flags);
 }
 
 /*
@@ -2614,7 +2651,7 @@ int __isolate_free_page(struct page *page, unsigned int order)
                 for (; page < endpage; page += pageblock_nr_pages) {
                         int mt = get_pageblock_migratetype(page);
                         if (!is_migrate_isolate(mt) && !is_migrate_cma(mt)
-                                && mt != MIGRATE_HIGHATOMIC)
+                            && !is_migrate_highatomic(mt))
                                 set_pageblock_migratetype(page,
                                                           MIGRATE_MOVABLE);
                 }
@@ -2654,8 +2691,6 @@ static struct page *__rmqueue_pcplist(struct zone *zone, int migratetype,
 {
         struct page *page;
 
-        VM_BUG_ON(in_interrupt());
-
         do {
                 if (list_empty(list)) {
                         pcp->count += rmqueue_bulk(zone, 0,
@@ -2686,8 +2721,9 @@ static struct page *rmqueue_pcplist(struct zone *preferred_zone,
         struct list_head *list;
         bool cold = ((gfp_flags & __GFP_COLD) != 0);
         struct page *page;
+        unsigned long flags;
 
-        preempt_disable();
+        local_irq_save(flags);
         pcp = &this_cpu_ptr(zone->pageset)->pcp;
         list = &pcp->lists[migratetype];
         page = __rmqueue_pcplist(zone,  migratetype, cold, pcp, list);
@@ -2695,7 +2731,7 @@ static struct page *rmqueue_pcplist(struct zone *preferred_zone,
                 __count_zid_vm_events(PGALLOC, page_zonenum(page), 1 << order);
                 zone_statistics(preferred_zone, zone);
         }
-        preempt_enable();
+        local_irq_restore(flags);
         return page;
 }
 
@@ -2711,7 +2747,7 @@ struct page *rmqueue(struct zone *preferred_zone,
         unsigned long flags;
         struct page *page;
 
-        if (likely(order == 0) && !in_interrupt()) {
+        if (likely(order == 0)) {
                 page = rmqueue_pcplist(preferred_zone, zone, order,
                                 gfp_flags, migratetype);
                 goto out;
@@ -3113,8 +3149,7 @@ void warn_alloc(gfp_t gfp_mask, nodemask_t *nodemask, const char *fmt, ...)
         static DEFINE_RATELIMIT_STATE(nopage_rs, DEFAULT_RATELIMIT_INTERVAL,
                                       DEFAULT_RATELIMIT_BURST);
 
-        if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs) ||
-            debug_guardpage_minorder() > 0)
+        if ((gfp_mask & __GFP_NOWARN) || !__ratelimit(&nopage_rs))
                 return;
 
         pr_warn("%s: ", current->comm);
@@ -3248,14 +3283,15 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
                 enum compact_priority prio, enum compact_result *compact_result)
 {
         struct page *page;
+        unsigned int noreclaim_flag;
 
         if (!order)
                 return NULL;
 
-        current->flags |= PF_MEMALLOC;
+        noreclaim_flag = memalloc_noreclaim_save();
         *compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
                                                                         prio);
-        current->flags &= ~PF_MEMALLOC;
+        memalloc_noreclaim_restore(noreclaim_flag);
 
         if (*compact_result <= COMPACT_INACTIVE)
                 return NULL;
@@ -3402,12 +3438,13 @@ __perform_reclaim(gfp_t gfp_mask, unsigned int order,
 {
         struct reclaim_state reclaim_state;
         int progress;
+        unsigned int noreclaim_flag;
 
         cond_resched();
 
         /* We now go into synchronous reclaim */
         cpuset_memory_pressure_bump();
-        current->flags |= PF_MEMALLOC;
+        noreclaim_flag = memalloc_noreclaim_save();
         lockdep_set_current_reclaim_state(gfp_mask);
         reclaim_state.reclaimed_slab = 0;
         current->reclaim_state = &reclaim_state;
@@ -3417,7 +3454,7 @@ __perform_reclaim(gfp_t gfp_mask, unsigned int order,
 
         current->reclaim_state = NULL;
         lockdep_clear_current_reclaim_state();
-        current->flags &= ~PF_MEMALLOC;
+        memalloc_noreclaim_restore(noreclaim_flag);
 
         cond_resched();
 
@@ -3525,19 +3562,12 @@ bool gfp_pfmemalloc_allowed(gfp_t gfp_mask)
 }
 
 /*
- * Maximum number of reclaim retries without any progress before OOM killer
- * is consider as the only way to move forward.
- */
-#define MAX_RECLAIM_RETRIES 16
-
-/*
  * Checks whether it makes sense to retry the reclaim to make a forward progress
  * for the given allocation request.
- * The reclaim feedback represented by did_some_progress (any progress during
- * the last reclaim round) and no_progress_loops (number of reclaim rounds without
- * any progress in a row) is considered as well as the reclaimable pages on the
- * applicable zone list (with a backoff mechanism which is a function of
- * no_progress_loops).
+ *
+ * We give up when we either have tried MAX_RECLAIM_RETRIES in a row
+ * without success, or when we couldn't even meet the watermark if we
+ * reclaimed all remaining pages on the LRU lists.
  *
  * Returns true if a retry is viable or false to enter the oom path.
  */
@@ -3582,13 +3612,11 @@ should_reclaim_retry(gfp_t gfp_mask, unsigned order,
                 bool wmark;
 
                 available = reclaimable = zone_reclaimable_pages(zone);
-                available -= DIV_ROUND_UP((*no_progress_loops) * available,
-                                          MAX_RECLAIM_RETRIES);
                 available += zone_page_state_snapshot(zone, NR_FREE_PAGES);
 
                 /*
-                 * Would the allocation succeed if we reclaimed the whole
-                 * available?
+                 * Would the allocation succeed if we reclaimed all
+                 * reclaimable pages?
                  */
                 wmark = __zone_watermark_ok(zone, order, min_wmark,
                                 ac_classzone_idx(ac), alloc_flags, available);
@@ -3639,6 +3667,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
                                                 struct alloc_context *ac)
 {
         bool can_direct_reclaim = gfp_mask & __GFP_DIRECT_RECLAIM;
+        const bool costly_order = order > PAGE_ALLOC_COSTLY_ORDER;
         struct page *page = NULL;
         unsigned int alloc_flags;
         unsigned long did_some_progress;
@@ -3706,12 +3735,17 @@ retry_cpuset:
 
         /*
          * For costly allocations, try direct compaction first, as it's likely
-         * that we have enough base pages and don't need to reclaim. Don't try
-         * that for allocations that are allowed to ignore watermarks, as the
-         * ALLOC_NO_WATERMARKS attempt didn't yet happen.
+         * that we have enough base pages and don't need to reclaim. For non-
+         * movable high-order allocations, do that as well, as compaction will
+         * try prevent permanent fragmentation by migrating from blocks of the
+         * same migratetype.
+         * Don't try this for allocations that are allowed to ignore
+         * watermarks, as the ALLOC_NO_WATERMARKS attempt didn't yet happen.
          */
-        if (can_direct_reclaim && order > PAGE_ALLOC_COSTLY_ORDER &&
-                !gfp_pfmemalloc_allowed(gfp_mask)) {
+        if (can_direct_reclaim &&
+                        (costly_order ||
+                           (order > 0 && ac->migratetype != MIGRATE_MOVABLE))
+                        && !gfp_pfmemalloc_allowed(gfp_mask)) {
                 page = __alloc_pages_direct_compact(gfp_mask, order,
                                                 alloc_flags, ac,
                                                 INIT_COMPACT_PRIORITY,
@@ -3723,7 +3757,7 @@ retry_cpuset:
                  * Checks for costly allocations with __GFP_NORETRY, which
                  * includes THP page fault allocations
                  */
-                if (gfp_mask & __GFP_NORETRY) {
+                if (costly_order && (gfp_mask & __GFP_NORETRY)) {
                         /*
                          * If compaction is deferred for high-order allocations,
                          * it is because sync compaction recently failed. If
@@ -3774,7 +3808,7 @@ retry:
 
         /* Make sure we know about allocations which stall for too long */
         if (time_after(jiffies, alloc_start + stall_timeout)) {
-                warn_alloc(gfp_mask, ac->nodemask,
+                warn_alloc(gfp_mask & ~__GFP_NOWARN, ac->nodemask,
                         "page allocation stalls for %ums, order:%u",
                         jiffies_to_msecs(jiffies-alloc_start), order);
                 stall_timeout += 10 * HZ;
@@ -3804,7 +3838,7 @@ retry:
          * Do not retry costly high order allocations unless they are
          * __GFP_REPEAT
          */
-        if (order > PAGE_ALLOC_COSTLY_ORDER && !(gfp_mask & __GFP_REPEAT))
+        if (costly_order && !(gfp_mask & __GFP_REPEAT))
                 goto nopage;
 
         if (should_reclaim_retry(gfp_mask, order, ac, alloc_flags,
@@ -3974,10 +4008,12 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
                 goto out;
 
         /*
-         * Runtime PM, block IO and its error handling path can deadlock
-         * because I/O on the device might not complete.
+         * Apply scoped allocation constraints. This is mainly about GFP_NOFS
+         * resp. GFP_NOIO which has to be inherited for all allocation requests
+         * from a particular context which has been marked by
+         * memalloc_no{fs,io}_{save,restore}.
          */
-        alloc_mask = memalloc_noio_flags(gfp_mask);
+        alloc_mask = current_gfp_context(gfp_mask);
         ac.spread_dirty_pages = false;
 
         /*
@@ -4250,7 +4286,8 @@ EXPORT_SYMBOL(free_pages_exact);
  * nr_free_zone_pages() counts the number of counts pages which are beyond the
  * high watermark within all zones at or below a given zone index.  For each
  * zone, the number of pages is calculated as:
- *     managed_pages - high_pages
+ *
+ *     nr_free_zone_pages = managed_pages - high_pages
  */
 static unsigned long nr_free_zone_pages(int offset)
 {
@@ -4512,7 +4549,6 @@ void show_free_areas(unsigned int filter, nodemask_t *nodemask)
 #endif
                         " writeback_tmp:%lukB"
                         " unstable:%lukB"
-                        " pages_scanned:%lu"
                         " all_unreclaimable? %s"
                         "\n",
                         pgdat->node_id,
@@ -4535,8 +4571,8 @@ void show_free_areas(unsigned int filter, nodemask_t *nodemask)
 #endif
                         K(node_page_state(pgdat, NR_WRITEBACK_TEMP)),
                         K(node_page_state(pgdat, NR_UNSTABLE_NFS)),
-                        node_page_state(pgdat, NR_PAGES_SCANNED),
-                        !pgdat_reclaimable(pgdat) ? "yes" : "no");
+                        pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES ?
+                                "yes" : "no");
         }
 
         for_each_populated_zone(zone) {
@@ -7431,7 +7467,7 @@ int alloc_contig_range(unsigned long start, unsigned long end,
                 .zone = page_zone(pfn_to_page(start)),
                 .mode = MIGRATE_SYNC,
                 .ignore_skip_hint = true,
-                .gfp_mask = memalloc_noio_flags(gfp_mask),
+                .gfp_mask = current_gfp_context(gfp_mask),
         };
         INIT_LIST_HEAD(&cc.migratepages);