mm: extract reclaim code from __alloc_pages_direct_reclaim()

This patch extracts common reclaim code from __alloc_pages_direct_reclaim()
function to separate function: __perform_reclaim() which can be later used
by alloc_contig_range().

Change-Id: Ia9d8b82018d91dc669488955b20f69f1cba43147
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Tested-by: Rob Clark <rob.clark@linaro.org>
Tested-by: Ohad Ben-Cohen <ohad@wizery.com>
Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Tested-by: Robert Nelson <robertcnelson@gmail.com>
Tested-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 906af2b..a17921f 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2138,16 +2138,13 @@
 }
 #endif /* CONFIG_COMPACTION */
 
-/* The really slow allocator path where we enter direct reclaim */
-static inline struct page *
-__alloc_pages_direct_reclaim(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)
+/* Perform direct synchronous page reclaim */
+static int
+__perform_reclaim(gfp_t gfp_mask, unsigned int order, struct zonelist *zonelist,
+		  nodemask_t *nodemask)
 {
-	struct page *page = NULL;
 	struct reclaim_state reclaim_state;
-	bool drained = false;
+	int progress;
 
 	cond_resched();
 
@@ -2158,7 +2155,7 @@
 	reclaim_state.reclaimed_slab = 0;
 	current->reclaim_state = &reclaim_state;
 
-	*did_some_progress = try_to_free_pages(zonelist, order, gfp_mask, nodemask);
+	progress = try_to_free_pages(zonelist, order, gfp_mask, nodemask);
 
 	current->reclaim_state = NULL;
 	lockdep_clear_current_reclaim_state();
@@ -2166,6 +2163,21 @@
 
 	cond_resched();
 
+	return progress;
+}
+
+/* The really slow allocator path where we enter direct reclaim */
+static inline struct page *
+__alloc_pages_direct_reclaim(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)
+{
+	struct page *page = NULL;
+	bool drained = false;
+
+	*did_some_progress = __perform_reclaim(gfp_mask, order, zonelist,
+					       nodemask);
 	if (unlikely(!(*did_some_progress)))
 		return NULL;