Merge remote-tracking branch 'stable/linux-3.0.y' into android-3.0
[firefly-linux-kernel-4.4.55.git] / mm / page_alloc.c
index 4e8985acdab8b5c234a6486b3c84caf5fb89dca0..bfe789472b4a1639d7885db9c6029485d25a4605 100644 (file)
@@ -127,6 +127,20 @@ void pm_restrict_gfp_mask(void)
        saved_gfp_mask = gfp_allowed_mask;
        gfp_allowed_mask &= ~GFP_IOFS;
 }
+
+static bool pm_suspending(void)
+{
+       if ((gfp_allowed_mask & GFP_IOFS) == GFP_IOFS)
+               return false;
+       return true;
+}
+
+#else
+
+static bool pm_suspending(void)
+{
+       return false;
+}
 #endif /* CONFIG_PM_SLEEP */
 
 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
@@ -176,6 +190,7 @@ static char * const zone_names[MAX_NR_ZONES] = {
 };
 
 int min_free_kbytes = 1024;
+int min_free_order_shift = 1;
 
 static unsigned long __meminitdata nr_kernel_pages;
 static unsigned long __meminitdata nr_all_pages;
@@ -355,8 +370,8 @@ void prep_compound_page(struct page *page, unsigned long order)
        __SetPageHead(page);
        for (i = 1; i < nr_pages; i++) {
                struct page *p = page + i;
-
                __SetPageTail(p);
+               set_page_count(p, 0);
                p->first_page = page;
        }
 }
@@ -540,7 +555,7 @@ static inline void __free_one_page(struct page *page,
                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);
+               higher_buddy = higher_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]);
@@ -1487,7 +1502,7 @@ static bool __zone_watermark_ok(struct zone *z, int order, unsigned long mark,
                free_pages -= z->free_area[o].nr_free << o;
 
                /* Require fewer higher order pages to be free */
-               min >>= 1;
+               min >>= min_free_order_shift;
 
                if (free_pages <= min)
                        return false;
@@ -1616,6 +1631,21 @@ static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
        set_bit(i, zlc->fullzones);
 }
 
+/*
+ * clear all zones full, called after direct reclaim makes progress so that
+ * a zone that was recently full is not skipped over for up to a second
+ */
+static void zlc_clear_zones_full(struct zonelist *zonelist)
+{
+       struct zonelist_cache *zlc;     /* cached zonelist speedup info */
+
+       zlc = zonelist->zlcache_ptr;
+       if (!zlc)
+               return;
+
+       bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
+}
+
 #else  /* CONFIG_NUMA */
 
 static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags)
@@ -1632,6 +1662,10 @@ static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z,
 static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z)
 {
 }
+
+static void zlc_clear_zones_full(struct zonelist *zonelist)
+{
+}
 #endif /* CONFIG_NUMA */
 
 /*
@@ -1664,7 +1698,7 @@ zonelist_scan:
                                continue;
                if ((alloc_flags & ALLOC_CPUSET) &&
                        !cpuset_zone_allowed_softwall(zone, gfp_mask))
-                               goto try_next_zone;
+                               continue;
 
                BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
                if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
@@ -1676,17 +1710,36 @@ zonelist_scan:
                                    classzone_idx, alloc_flags))
                                goto try_this_zone;
 
+                       if (NUMA_BUILD && !did_zlc_setup && nr_online_nodes > 1) {
+                               /*
+                                * we do zlc_setup if there are multiple nodes
+                                * and before considering the first zone allowed
+                                * by the cpuset.
+                                */
+                               allowednodes = zlc_setup(zonelist, alloc_flags);
+                               zlc_active = 1;
+                               did_zlc_setup = 1;
+                       }
+
                        if (zone_reclaim_mode == 0)
                                goto this_zone_full;
 
+                       /*
+                        * As we may have just activated ZLC, check if the first
+                        * eligible zone has failed zone_reclaim recently.
+                        */
+                       if (NUMA_BUILD && zlc_active &&
+                               !zlc_zone_worth_trying(zonelist, z, allowednodes))
+                               continue;
+
                        ret = zone_reclaim(zone, gfp_mask, order);
                        switch (ret) {
                        case ZONE_RECLAIM_NOSCAN:
                                /* did not scan */
-                               goto try_next_zone;
+                               continue;
                        case ZONE_RECLAIM_FULL:
                                /* scanned but unreclaimable */
-                               goto this_zone_full;
+                               continue;
                        default:
                                /* did we reclaim enough */
                                if (!zone_watermark_ok(zone, order, mark,
@@ -1703,16 +1756,6 @@ try_this_zone:
 this_zone_full:
                if (NUMA_BUILD)
                        zlc_mark_zone_full(zonelist, z);
-try_next_zone:
-               if (NUMA_BUILD && !did_zlc_setup && nr_online_nodes > 1) {
-                       /*
-                        * we do zlc_setup after the first zone is tried but only
-                        * if there are multiple nodes make it worthwhile
-                        */
-                       allowednodes = zlc_setup(zonelist, alloc_flags);
-                       zlc_active = 1;
-                       did_zlc_setup = 1;
-               }
        }
 
        if (unlikely(NUMA_BUILD && page == NULL && zlc_active)) {
@@ -1869,14 +1912,20 @@ 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,
-       bool sync_migration)
+       int migratetype, bool sync_migration,
+       bool *deferred_compaction,
+       unsigned long *did_some_progress)
 {
        struct page *page;
 
-       if (!order || compaction_deferred(preferred_zone))
+       if (!order)
                return NULL;
 
+       if (compaction_deferred(preferred_zone)) {
+               *deferred_compaction = true;
+               return NULL;
+       }
+
        current->flags |= PF_MEMALLOC;
        *did_some_progress = try_to_compact_pages(zonelist, order, gfp_mask,
                                                nodemask, sync_migration);
@@ -1904,7 +1953,13 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
                 * but not enough to satisfy watermarks.
                 */
                count_vm_event(COMPACTFAIL);
-               defer_compaction(preferred_zone);
+
+               /*
+                * As async compaction considers a subset of pageblocks, only
+                * defer if the failure was a sync compaction failure.
+                */
+               if (sync_migration)
+                       defer_compaction(preferred_zone);
 
                cond_resched();
        }
@@ -1916,8 +1971,9 @@ 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,
-       bool sync_migration)
+       int migratetype, bool sync_migration,
+       bool *deferred_compaction,
+       unsigned long *did_some_progress)
 {
        return NULL;
 }
@@ -1954,6 +2010,10 @@ __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
        if (unlikely(!(*did_some_progress)))
                return NULL;
 
+       /* After successful reclaim, reconsider all zones for allocation */
+       if (NUMA_BUILD)
+               zlc_clear_zones_full(zonelist);
+
 retry:
        page = get_page_from_freelist(gfp_mask, nodemask, order,
                                        zonelist, high_zoneidx,
@@ -2063,6 +2123,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
        unsigned long pages_reclaimed = 0;
        unsigned long did_some_progress;
        bool sync_migration = false;
+       bool deferred_compaction = false;
 
        /*
         * In the slowpath, we sanity check order to avoid ever trying to
@@ -2143,12 +2204,22 @@ rebalance:
                                        zonelist, high_zoneidx,
                                        nodemask,
                                        alloc_flags, preferred_zone,
-                                       migratetype, &did_some_progress,
-                                       sync_migration);
+                                       migratetype, sync_migration,
+                                       &deferred_compaction,
+                                       &did_some_progress);
        if (page)
                goto got_pg;
        sync_migration = true;
 
+       /*
+        * If compaction is deferred for high-order allocations, it is because
+        * sync compaction recently failed. In this is the case and the caller
+        * has requested the system not be heavily disrupted, fail the
+        * allocation now instead of entering direct reclaim
+        */
+       if (deferred_compaction && (gfp_mask & __GFP_NO_KSWAPD))
+               goto nopage;
+
        /* Try direct reclaim and then allocating */
        page = __alloc_pages_direct_reclaim(gfp_mask, order,
                                        zonelist, high_zoneidx,
@@ -2193,6 +2264,14 @@ rebalance:
 
                        goto restart;
                }
+
+               /*
+                * Suspend converts GFP_KERNEL to __GFP_WAIT which can
+                * prevent reclaim making forward progress without
+                * invoking OOM. Bail if we are suspending
+                */
+               if (pm_suspending())
+                       goto nopage;
        }
 
        /* Check if we should retry the allocation */
@@ -2211,8 +2290,9 @@ rebalance:
                                        zonelist, high_zoneidx,
                                        nodemask,
                                        alloc_flags, preferred_zone,
-                                       migratetype, &did_some_progress,
-                                       sync_migration);
+                                       migratetype, sync_migration,
+                                       &deferred_compaction,
+                                       &did_some_progress);
                if (page)
                        goto got_pg;
        }
@@ -2236,8 +2316,9 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
 {
        enum zone_type high_zoneidx = gfp_zone(gfp_mask);
        struct zone *preferred_zone;
-       struct page *page;
+       struct page *page = NULL;
        int migratetype = allocflags_to_migratetype(gfp_mask);
+       unsigned int cpuset_mems_cookie;
 
        gfp_mask &= gfp_allowed_mask;
 
@@ -2256,15 +2337,15 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
        if (unlikely(!zonelist->_zonerefs->zone))
                return NULL;
 
-       get_mems_allowed();
+retry_cpuset:
+       cpuset_mems_cookie = get_mems_allowed();
+
        /* The preferred zone is used for statistics later */
        first_zones_zonelist(zonelist, high_zoneidx,
                                nodemask ? : &cpuset_current_mems_allowed,
                                &preferred_zone);
-       if (!preferred_zone) {
-               put_mems_allowed();
-               return NULL;
-       }
+       if (!preferred_zone)
+               goto out;
 
        /* First allocation attempt */
        page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
@@ -2274,9 +2355,19 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
                page = __alloc_pages_slowpath(gfp_mask, order,
                                zonelist, high_zoneidx, nodemask,
                                preferred_zone, migratetype);
-       put_mems_allowed();
 
        trace_mm_page_alloc(page, order, gfp_mask, migratetype);
+
+out:
+       /*
+        * When updating a task's mems_allowed, it is possible to race with
+        * parallel threads in such a way that an allocation can fail while
+        * the mask is being updated. If a page allocation is about to fail,
+        * check if the cpuset changed during allocation and if so, retry.
+        */
+       if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page))
+               goto retry_cpuset;
+
        return page;
 }
 EXPORT_SYMBOL(__alloc_pages_nodemask);
@@ -2500,13 +2591,15 @@ void si_meminfo_node(struct sysinfo *val, int nid)
 bool skip_free_areas_node(unsigned int flags, int nid)
 {
        bool ret = false;
+       unsigned int cpuset_mems_cookie;
 
        if (!(flags & SHOW_MEM_FILTER_NODES))
                goto out;
 
-       get_mems_allowed();
-       ret = !node_isset(nid, cpuset_current_mems_allowed);
-       put_mems_allowed();
+       do {
+               cpuset_mems_cookie = get_mems_allowed();
+               ret = !node_isset(nid, cpuset_current_mems_allowed);
+       } while (!put_mems_allowed(cpuset_mems_cookie));
 out:
        return ret;
 }
@@ -3356,9 +3449,15 @@ static void setup_zone_migrate_reserve(struct zone *zone)
        unsigned long block_migratetype;
        int reserve;
 
-       /* Get the start pfn, end pfn and the number of blocks to reserve */
+       /*
+        * Get the start pfn, end pfn and the number of blocks to reserve
+        * We have to be careful to be aligned to pageblock_nr_pages to
+        * make sure that we always check pfn_valid for the first page in
+        * the block.
+        */
        start_pfn = zone->zone_start_pfn;
        end_pfn = start_pfn + zone->spanned_pages;
+       start_pfn = roundup(start_pfn, pageblock_nr_pages);
        reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >>
                                                        pageblock_order;
 
@@ -3380,25 +3479,33 @@ static void setup_zone_migrate_reserve(struct zone *zone)
                if (page_to_nid(page) != zone_to_nid(zone))
                        continue;
 
-               /* Blocks with reserved pages will never free, skip them. */
-               block_end_pfn = min(pfn + pageblock_nr_pages, end_pfn);
-               if (pageblock_is_reserved(pfn, block_end_pfn))
-                       continue;
-
                block_migratetype = get_pageblock_migratetype(page);
 
-               /* If this block is reserved, account for it */
-               if (reserve > 0 && block_migratetype == MIGRATE_RESERVE) {
-                       reserve--;
-                       continue;
-               }
+               /* Only test what is necessary when the reserves are not met */
+               if (reserve > 0) {
+                       /*
+                        * Blocks with reserved pages will never free, skip
+                        * them.
+                        */
+                       block_end_pfn = min(pfn + pageblock_nr_pages, end_pfn);
+                       if (pageblock_is_reserved(pfn, block_end_pfn))
+                               continue;
 
-               /* Suitable for reserving if this block is movable */
-               if (reserve > 0 && block_migratetype == MIGRATE_MOVABLE) {
-                       set_pageblock_migratetype(page, MIGRATE_RESERVE);
-                       move_freepages_block(zone, page, MIGRATE_RESERVE);
-                       reserve--;
-                       continue;
+                       /* If this block is reserved, account for it */
+                       if (block_migratetype == MIGRATE_RESERVE) {
+                               reserve--;
+                               continue;
+                       }
+
+                       /* Suitable for reserving if this block is movable */
+                       if (block_migratetype == MIGRATE_MOVABLE) {
+                               set_pageblock_migratetype(page,
+                                                       MIGRATE_RESERVE);
+                               move_freepages_block(zone, page,
+                                                       MIGRATE_RESERVE);
+                               reserve--;
+                               continue;
+                       }
                }
 
                /*
@@ -5527,6 +5634,17 @@ __count_immobile_pages(struct zone *zone, struct page *page, int count)
 bool is_pageblock_removable_nolock(struct page *page)
 {
        struct zone *zone = page_zone(page);
+       unsigned long pfn = page_to_pfn(page);
+
+       /*
+        * We have to be careful here because we are iterating over memory
+        * sections which are not zone aware so we might end up outside of
+        * the zone but still within the section.
+        */
+       if (!zone || zone->zone_start_pfn > pfn ||
+                       zone->zone_start_pfn + zone->spanned_pages <= pfn)
+               return false;
+
        return __count_immobile_pages(zone, page, 0);
 }