1 files changed, 69 insertions, 4 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 2e132b9e7a93..09bf2c5f8b4b 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -789,6 +789,57 @@ static inline int page_is_buddy(struct page *page, struct page *buddy,
 	return 0;
 }
 
+#ifdef CONFIG_COMPACTION
+static inline struct capture_control *task_capc(struct zone *zone)
+{
+	struct capture_control *capc = current->capture_control;
+
+	return capc &&
+		!(current->flags & PF_KTHREAD) &&
+		!capc->page &&
+		capc->cc->zone == zone &&
+		capc->cc->direct_compaction ? capc : NULL;
+}
+
+static inline bool
+compaction_capture(struct capture_control *capc, struct page *page,
+		   int order, int migratetype)
+{
+	if (!capc || order != capc->cc->order)
+		return false;
+
+	/* Do not accidentally pollute CMA or isolated regions*/
+	if (is_migrate_cma(migratetype) ||
+	    is_migrate_isolate(migratetype))
+		return false;
+
+	/*
+	 * Do not let lower order allocations polluate a movable pageblock.
+	 * This might let an unmovable request use a reclaimable pageblock
+	 * and vice-versa but no more than normal fallback logic which can
+	 * have trouble finding a high-order free page.
+	 */
+	if (order < pageblock_order && migratetype == MIGRATE_MOVABLE)
+		return false;
+
+	capc->page = page;
+	return true;
+}
+
+#else
+static inline struct capture_control *task_capc(struct zone *zone)
+{
+	return NULL;
+}
+
+static inline bool
+compaction_capture(struct capture_control *capc, struct page *page,
+		   int order, int migratetype)
+{
+	return false;
+}
+#endif /* CONFIG_COMPACTION */
+
 /*
  * Freeing function for a buddy system allocator.
  *
@@ -822,6 +873,7 @@ static inline void __free_one_page(struct page *page,
 	unsigned long uninitialized_var(buddy_pfn);
 	struct page *buddy;
 	unsigned int max_order;
+	struct capture_control *capc = task_capc(zone);
 
 	max_order = min_t(unsigned int, MAX_ORDER, pageblock_order + 1);
 
@@ -837,6 +889,11 @@ static inline void __free_one_page(struct page *page,
 
 continue_merging:
 	while (order < max_order - 1) {
+		if (compaction_capture(capc, page, order, migratetype)) {
+			__mod_zone_freepage_state(zone, -(1 << order),
+								migratetype);
+			return;
+		}
 		buddy_pfn = __find_buddy_pfn(pfn, order);
 		buddy = page + (buddy_pfn - pfn);
 
@@ -3710,7 +3767,7 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
 		unsigned int alloc_flags, const struct alloc_context *ac,
 		enum compact_priority prio, enum compact_result *compact_result)
 {
-	struct page *page;
+	struct page *page = NULL;
 	unsigned long pflags;
 	unsigned int noreclaim_flag;
 
@@ -3721,13 +3778,15 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
 	noreclaim_flag = memalloc_noreclaim_save();
 
 	*compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
-									prio);
+								prio, &page);
 
 	memalloc_noreclaim_restore(noreclaim_flag);
 	psi_memstall_leave(&pflags);
 
-	if (*compact_result <= COMPACT_INACTIVE)
+	if (*compact_result <= COMPACT_INACTIVE) {
+		WARN_ON_ONCE(page);
 		return NULL;
+	}
 
 	/*
 	 * At least in one zone compaction wasn't deferred or skipped, so let's
@@ -3735,7 +3794,13 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
 	 */
 	count_vm_event(COMPACTSTALL);
 
-	page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
+	/* Prep a captured page if available */
+	if (page)
+		prep_new_page(page, order, gfp_mask, alloc_flags);
+
+	/* Try get a page from the freelist if available */
+	if (!page)
+		page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
 
 	if (page) {
 		struct zone *zone = page_zone(page);