1 files changed, 106 insertions, 59 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index ff7e15872398..90c1439549fd 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -357,6 +357,7 @@ void prep_compound_page(struct page *page, unsigned long order)
         }
 }
 
+/* update __split_huge_page_refcount if you change this function */
 static int destroy_compound_page(struct page *page, unsigned long order)
 {
         int i;
@@ -426,18 +427,10 @@ static inline void rmv_page_order(struct page *page)
  *
  * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
  */
-static inline struct page *
-__page_find_buddy(struct page *page, unsigned long page_idx, unsigned int order)
-{
-        unsigned long buddy_idx = page_idx ^ (1 << order);
-
-        return page + (buddy_idx - page_idx);
-}
-
 static inline unsigned long
-__find_combined_index(unsigned long page_idx, unsigned int order)
+__find_buddy_index(unsigned long page_idx, unsigned int order)
 {
-        return (page_idx & ~(1 << order));
+        return page_idx ^ (1 << order);
 }
 
 /*
@@ -448,8 +441,8 @@ __find_combined_index(unsigned long page_idx, unsigned int order)
  * (c) a page and its buddy have the same order &&
  * (d) a page and its buddy are in the same zone.
  *
- * For recording whether a page is in the buddy system, we use PG_buddy.
- * Setting, clearing, and testing PG_buddy is serialized by zone->lock.
+ * For recording whether a page is in the buddy system, we set ->_mapcount -2.
+ * Setting, clearing, and testing _mapcount -2 is serialized by zone->lock.
  *
  * For recording page's order, we use page_private(page).
  */
@@ -482,7 +475,7 @@ static inline int page_is_buddy(struct page *page, struct page *buddy,
  * as necessary, plus some accounting needed to play nicely with other
  * parts of the VM system.
  * At each level, we keep a list of pages, which are heads of continuous
- * free pages of length of (1 << order) and marked with PG_buddy. Page's
+ * free pages of length of (1 << order) and marked with _mapcount -2. Page's
  * order is recorded in page_private(page) field.
  * So when we are allocating or freeing one, we can derive the state of the
  * other.  That is, if we allocate a small block, and both were   
@@ -499,6 +492,7 @@ static inline void __free_one_page(struct page *page,
 {
         unsigned long page_idx;
         unsigned long combined_idx;
+        unsigned long uninitialized_var(buddy_idx);
         struct page *buddy;
 
         if (unlikely(PageCompound(page)))
@@ -513,7 +507,8 @@ static inline void __free_one_page(struct page *page,
         VM_BUG_ON(bad_range(zone, page));
 
         while (order < MAX_ORDER-1) {
-                buddy = __page_find_buddy(page, page_idx, order);
+                buddy_idx = __find_buddy_index(page_idx, order);
+                buddy = page + (buddy_idx - page_idx);
                 if (!page_is_buddy(page, buddy, order))
                         break;
 
@@ -521,7 +516,7 @@ static inline void __free_one_page(struct page *page,
                 list_del(&buddy->lru);
                 zone->free_area[order].nr_free--;
                 rmv_page_order(buddy);
-                combined_idx = __find_combined_index(page_idx, order);
+                combined_idx = buddy_idx & page_idx;
                 page = page + (combined_idx - page_idx);
                 page_idx = combined_idx;
                 order++;
@@ -538,9 +533,10 @@ static inline void __free_one_page(struct page *page,
          */
         if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) {
                 struct page *higher_page, *higher_buddy;
-                combined_idx = __find_combined_index(page_idx, order);
-                higher_page = page + combined_idx - page_idx;
-                higher_buddy = __page_find_buddy(higher_page, combined_idx, order + 1);
+                combined_idx = buddy_idx & page_idx;
+                higher_page = page + (combined_idx - page_idx);
+                buddy_idx = __find_buddy_index(combined_idx, order + 1);
+                higher_buddy = page + (buddy_idx - combined_idx);
                 if (page_is_buddy(higher_page, higher_buddy, order + 1)) {
                         list_add_tail(&page->lru,
                                 &zone->free_area[order].free_list[migratetype]);
@@ -651,13 +647,10 @@ static bool free_pages_prepare(struct page *page, unsigned int order)
         trace_mm_page_free_direct(page, order);
         kmemcheck_free_shadow(page, order);
 
-        for (i = 0; i < (1 << order); i++) {
-                struct page *pg = page + i;
-
-                if (PageAnon(pg))
-                        pg->mapping = NULL;
-                bad += free_pages_check(pg);
-        }
+        if (PageAnon(page))
+                page->mapping = NULL;
+        for (i = 0; i < (1 << order); i++)
+                bad += free_pages_check(page + i);
         if (bad)
                 return false;
 
@@ -1460,24 +1453,24 @@ static inline int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
 #endif /* CONFIG_FAIL_PAGE_ALLOC */
 
 /*
- * Return 1 if free pages are above 'mark'. This takes into account the order
+ * Return true if free pages are above 'mark'. This takes into account the order
  * of the allocation.
  */
-int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
-                      int classzone_idx, int alloc_flags)
+static bool __zone_watermark_ok(struct zone *z, int order, unsigned long mark,
+                      int classzone_idx, int alloc_flags, long free_pages)
 {
         /* free_pages my go negative - that's OK */
         long min = mark;
-        long free_pages = zone_nr_free_pages(z) - (1 << order) + 1;
         int o;
 
+        free_pages -= (1 << order) + 1;
         if (alloc_flags & ALLOC_HIGH)
                 min -= min / 2;
         if (alloc_flags & ALLOC_HARDER)
                 min -= min / 4;
 
         if (free_pages <= min + z->lowmem_reserve[classzone_idx])
-                return 0;
+                return false;
         for (o = 0; o < order; o++) {
                 /* At the next order, this order's pages become unavailable */
                 free_pages -= z->free_area[o].nr_free << o;
@@ -1486,9 +1479,28 @@ int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
                 min >>= 1;
 
                 if (free_pages <= min)
-                        return 0;
+                        return false;
         }
-        return 1;
+        return true;
+}
+
+bool zone_watermark_ok(struct zone *z, int order, unsigned long mark,
+                      int classzone_idx, int alloc_flags)
+{
+        return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
+                                        zone_page_state(z, NR_FREE_PAGES));
+}
+
+bool zone_watermark_ok_safe(struct zone *z, int order, unsigned long mark,
+                      int classzone_idx, int alloc_flags)
+{
+        long free_pages = zone_page_state(z, NR_FREE_PAGES);
+
+        if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
+                free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);
+
+        return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
+                                                                free_pages);
 }
 
 #ifdef CONFIG_NUMA
@@ -1793,15 +1805,18 @@ static struct page *
 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
         struct zonelist *zonelist, enum zone_type high_zoneidx,
         nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
-        int migratetype, unsigned long *did_some_progress)
+        int migratetype, unsigned long *did_some_progress,
+        bool sync_migration)
 {
         struct page *page;
 
         if (!order || compaction_deferred(preferred_zone))
                 return NULL;
 
+        current->flags |= PF_MEMALLOC;
         *did_some_progress = try_to_compact_pages(zonelist, order, gfp_mask,
-                                                                nodemask);
+                                                nodemask, sync_migration);
+        current->flags &= ~PF_MEMALLOC;
         if (*did_some_progress != COMPACT_SKIPPED) {
 
                 /* Page migration frees to the PCP lists but we want merging */
@@ -1837,7 +1852,8 @@ static inline struct page *
 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
         struct zonelist *zonelist, enum zone_type high_zoneidx,
         nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
-        int migratetype, unsigned long *did_some_progress)
+        int migratetype, unsigned long *did_some_progress,
+        bool sync_migration)
 {
         return NULL;
 }
@@ -1852,23 +1868,22 @@ __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
 {
         struct page *page = NULL;
         struct reclaim_state reclaim_state;
-        struct task_struct *p = current;
         bool drained = false;
 
         cond_resched();
 
         /* We now go into synchronous reclaim */
         cpuset_memory_pressure_bump();
-        p->flags |= PF_MEMALLOC;
+        current->flags |= PF_MEMALLOC;
         lockdep_set_current_reclaim_state(gfp_mask);
         reclaim_state.reclaimed_slab = 0;
-        p->reclaim_state = &reclaim_state;
+        current->reclaim_state = &reclaim_state;
 
         *did_some_progress = try_to_free_pages(zonelist, order, gfp_mask, nodemask);
 
-        p->reclaim_state = NULL;
+        current->reclaim_state = NULL;
         lockdep_clear_current_reclaim_state();
-        p->flags &= ~PF_MEMALLOC;
+        current->flags &= ~PF_MEMALLOC;
 
         cond_resched();
 
@@ -1920,19 +1935,19 @@ __alloc_pages_high_priority(gfp_t gfp_mask, unsigned int order,
 
 static inline
 void wake_all_kswapd(unsigned int order, struct zonelist *zonelist,
-                                                enum zone_type high_zoneidx)
+                                                enum zone_type high_zoneidx,
+                                                enum zone_type classzone_idx)
 {
         struct zoneref *z;
         struct zone *zone;
 
         for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
-                wakeup_kswapd(zone, order);
+                wakeup_kswapd(zone, order, classzone_idx);
 }
 
 static inline int
 gfp_to_alloc_flags(gfp_t gfp_mask)
 {
-        struct task_struct *p = current;
         int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET;
         const gfp_t wait = gfp_mask & __GFP_WAIT;
 
@@ -1948,18 +1963,23 @@ gfp_to_alloc_flags(gfp_t gfp_mask)
         alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH);
 
         if (!wait) {
-                alloc_flags |= ALLOC_HARDER;
+                /*
+                 * Not worth trying to allocate harder for
+                 * __GFP_NOMEMALLOC even if it can't schedule.
+                 */
+                if  (!(gfp_mask & __GFP_NOMEMALLOC))
+                        alloc_flags |= ALLOC_HARDER;
                 /*
                  * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
                  * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
                  */
                 alloc_flags &= ~ALLOC_CPUSET;
-        } else if (unlikely(rt_task(p)) && !in_interrupt())
+        } else if (unlikely(rt_task(current)) && !in_interrupt())
                 alloc_flags |= ALLOC_HARDER;
 
         if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) {
                 if (!in_interrupt() &&
-                    ((p->flags & PF_MEMALLOC) ||
+                    ((current->flags & PF_MEMALLOC) ||
                      unlikely(test_thread_flag(TIF_MEMDIE))))
                         alloc_flags |= ALLOC_NO_WATERMARKS;
         }
@@ -1978,7 +1998,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
         int alloc_flags;
         unsigned long pages_reclaimed = 0;
         unsigned long did_some_progress;
-        struct task_struct *p = current;
+        bool sync_migration = false;
 
         /*
          * In the slowpath, we sanity check order to avoid ever trying to
@@ -2003,7 +2023,9 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
                 goto nopage;
 
 restart:
-        wake_all_kswapd(order, zonelist, high_zoneidx);
+        if (!(gfp_mask & __GFP_NO_KSWAPD))
+                wake_all_kswapd(order, zonelist, high_zoneidx,
+                                                zone_idx(preferred_zone));
 
         /*
          * OK, we're below the kswapd watermark and have kicked background
@@ -2034,21 +2056,26 @@ rebalance:
                 goto nopage;
 
         /* Avoid recursion of direct reclaim */
-        if (p->flags & PF_MEMALLOC)
+        if (current->flags & PF_MEMALLOC)
                 goto nopage;
 
         /* Avoid allocations with no watermarks from looping endlessly */
         if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
                 goto nopage;
 
-        /* Try direct compaction */
+        /*
+         * Try direct compaction. The first pass is asynchronous. Subsequent
+         * attempts after direct reclaim are synchronous
+         */
         page = __alloc_pages_direct_compact(gfp_mask, order,
                                         zonelist, high_zoneidx,
                                         nodemask,
                                         alloc_flags, preferred_zone,
-                                        migratetype, &did_some_progress);
+                                        migratetype, &did_some_progress,
+                                        sync_migration);
         if (page)
                 goto got_pg;
+        sync_migration = true;
 
         /* Try direct reclaim and then allocating */
         page = __alloc_pages_direct_reclaim(gfp_mask, order,
@@ -2102,13 +2129,27 @@ rebalance:
                 /* Wait for some write requests to complete then retry */
                 wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50);
                 goto rebalance;
+        } else {
+                /*
+                 * High-order allocations do not necessarily loop after
+                 * direct reclaim and reclaim/compaction depends on compaction
+                 * being called after reclaim so call directly if necessary
+                 */
+                page = __alloc_pages_direct_compact(gfp_mask, order,
+                                        zonelist, high_zoneidx,
+                                        nodemask,
+                                        alloc_flags, preferred_zone,
+                                        migratetype, &did_some_progress,
+                                        sync_migration);
+                if (page)
+                        goto got_pg;
         }
 
 nopage:
         if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) {
                 printk(KERN_WARNING "%s: page allocation failure."
                         " order:%d, mode:0x%x\n",
-                        p->comm, order, gfp_mask);
+                        current->comm, order, gfp_mask);
                 dump_stack();
                 show_mem();
         }
@@ -2442,7 +2483,7 @@ void show_free_areas(void)
                         " all_unreclaimable? %s"
                         "\n",
                         zone->name,
-                        K(zone_nr_free_pages(zone)),
+                        K(zone_page_state(zone, NR_FREE_PAGES)),
                         K(min_wmark_pages(zone)),
                         K(low_wmark_pages(zone)),
                         K(high_wmark_pages(zone)),
@@ -2585,9 +2626,16 @@ static int __parse_numa_zonelist_order(char *s)
 
 static __init int setup_numa_zonelist_order(char *s)
 {
-        if (s)
-                return __parse_numa_zonelist_order(s);
-        return 0;
+        int ret;
+
+        if (!s)
+                return 0;
+
+        ret = __parse_numa_zonelist_order(s);
+        if (ret == 0)
+                strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN);
+
+        return ret;
 }
 early_param("numa_zonelist_order", setup_numa_zonelist_order);
 
@@ -4014,7 +4062,7 @@ static void __init setup_usemap(struct pglist_data *pgdat,
                 zone->pageblock_flags = alloc_bootmem_node(pgdat, usemapsize);
 }
 #else
-static void inline setup_usemap(struct pglist_data *pgdat,
+static inline void setup_usemap(struct pglist_data *pgdat,
                                 struct zone *zone, unsigned long zonesize) {}
 #endif /* CONFIG_SPARSEMEM */
 
@@ -5517,7 +5565,6 @@ static struct trace_print_flags pageflag_names[] = {
         {1UL << PG_swapcache,           "swapcache"     },
         {1UL << PG_mappedtodisk,        "mappedtodisk"  },
         {1UL << PG_reclaim,             "reclaim"       },
-        {1UL << PG_buddy,               "buddy"         },
         {1UL << PG_swapbacked,          "swapbacked"    },
         {1UL << PG_unevictable,         "unevictable"   },
 #ifdef CONFIG_MMU
@@ -5565,7 +5612,7 @@ void dump_page(struct page *page)
 {
         printk(KERN_ALERT
                "page:%p count:%d mapcount:%d mapping:%p index:%#lx\n",
-                page, page_count(page), page_mapcount(page),
+                page, atomic_read(&page->_count), page_mapcount(page),
                 page->mapping, page->index);
         dump_page_flags(page->flags);
 }