cma: redirect page allocation to CMA

CMA pages are designed to be used as fallback for movable allocations
and cannot be used for non-movable allocations. If CMA pages are
utilized poorly, non-movable allocations may end up getting starved if
all regular movable pages are allocated and the only pages left are
CMA. Always using CMA pages first creates unacceptable performance
problems. As a midway alternative, use CMA pages for certain
userspace allocations. The userspace pages can be migrated or dropped
quickly which giving decent utilization.

Change-Id: I6165dda01b705309eebabc6dfa67146b7a95c174
CRs-Fixed: 452508
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Heesub Shin <heesub.shin@samsung.com
[lauraa@codeaurora.org: Missing CONFIG_CMA guards, add commit text]
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
[lmark@codeaurora.org: resolve conflicts relating to
 MIGRATE_HIGHATOMIC and some other trivial merge conflicts]
Signed-off-by: Liam Mark <lmark@codeaurora.org>

1 files changed, 36 insertions, 8 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 1eafd75f402e..2695ca00653e 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1815,11 +1815,26 @@ static struct page *__rmqueue(struct zone *zone, unsigned int order,
 
 	page = __rmqueue_smallest(zone, order, migratetype);
 	if (unlikely(!page)) {
-		if (migratetype == MIGRATE_MOVABLE)
-			page = __rmqueue_cma_fallback(zone, order);
+		page = __rmqueue_fallback(zone, order, migratetype);
+	}
 
-		if (!page)
-			page = __rmqueue_fallback(zone, order, migratetype);
+	trace_mm_page_alloc_zone_locked(page, order, migratetype);
+	return page;
+}
+
+static struct page *__rmqueue_cma(struct zone *zone, unsigned int order,
+					int migratetype, gfp_t gfp_flags)
+{
+	struct page *page = 0;
+#ifdef CONFIG_CMA
+	if (migratetype == MIGRATE_MOVABLE && !zone->cma_alloc)
+		page = __rmqueue_cma_fallback(zone, order);
+	else
+#endif
+		page = __rmqueue_smallest(zone, order, migratetype);
+
+	if (unlikely(!page)) {
+		page = __rmqueue_fallback(zone, order, migratetype);
 	}
 
 	trace_mm_page_alloc_zone_locked(page, order, migratetype);
@@ -1833,13 +1848,17 @@ static struct page *__rmqueue(struct zone *zone, unsigned int order,
  */
 static int rmqueue_bulk(struct zone *zone, unsigned int order,
 			unsigned long count, struct list_head *list,
-			int migratetype, bool cold)
+			int migratetype, bool cold, int cma)
 {
 	int i;
 
 	spin_lock(&zone->lock);
 	for (i = 0; i < count; ++i) {
-		struct page *page = __rmqueue(zone, order, migratetype, 0);
+		struct page *page;
+		if (cma)
+			page = __rmqueue_cma(zone, order, migratetype, 0);
+		else
+			page = __rmqueue(zone, order, migratetype, 0);
 		if (unlikely(page == NULL))
 			break;
 
@@ -2229,7 +2248,8 @@ struct page *buffered_rmqueue(struct zone *preferred_zone,
 		if (list_empty(list)) {
 			pcp->count += rmqueue_bulk(zone, 0,
 					pcp->batch, list,
-					migratetype, cold);
+					migratetype, cold,
+					gfp_flags & __GFP_CMA);
 			if (unlikely(list_empty(list)))
 				goto failed;
 		}
@@ -2263,8 +2283,13 @@ struct page *buffered_rmqueue(struct zone *preferred_zone,
 			if (page)
 				trace_mm_page_alloc_zone_locked(page, order, migratetype);
 		}
-		if (!page)
+		if (!page) {
+		if (gfp_flags & __GFP_CMA)
+			page = __rmqueue_cma(zone, order, migratetype, gfp_flags);
+		else
 			page = __rmqueue(zone, order, migratetype, gfp_flags);
+
+		}
 		spin_unlock(&zone->lock);
 		if (!page)
 			goto failed;
@@ -6753,6 +6778,8 @@ int alloc_contig_range(unsigned long start, unsigned long end,
 	if (ret)
 		return ret;
 
+	cc.zone->cma_alloc = 1;
+
 	ret = __alloc_contig_migrate_range(&cc, start, end);
 	if (ret)
 		goto done;
@@ -6811,6 +6838,7 @@ int alloc_contig_range(unsigned long start, unsigned long end,
 done:
 	undo_isolate_page_range(pfn_max_align_down(start),
 				pfn_max_align_up(end), migratetype);
+	cc.zone->cma_alloc = 0;
 	return ret;
 }