[PATCH v2 10/12] mm/gup: use standard migration target allocation function

[js1304]

From: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>

There is no reason to implement it's own function for migration
target allocation. Use standard one.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
---
 mm/gup.c | 61 ++++++++++---------------------------------------------------
 1 file changed, 10 insertions(+), 51 deletions(-)

diff --git a/mm/gup.c b/mm/gup.c
index a49d7ea..0e4214d 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1593,58 +1593,16 @@ static bool check_dax_vmas(struct vm_area_struct **vmas, long nr_pages)
 }
 
 #ifdef CONFIG_CMA
-static struct page *new_non_cma_page(struct page *page,
+static struct page *alloc_migration_target_non_cma(struct page *page,
 				struct alloc_control *ac)
 {
-	/*
-	 * We want to make sure we allocate the new page from the same node
-	 * as the source page.
-	 */
-	int nid = page_to_nid(page);
-	/*
-	 * Trying to allocate a page for migration. Ignore allocation
-	 * failure warnings. We don't force __GFP_THISNODE here because
-	 * this node here is the node where we have CMA reservation and
-	 * in some case these nodes will have really less non movable
-	 * allocation memory.
-	 */
-	gfp_t gfp_mask = GFP_USER | __GFP_NOWARN;
-
-	if (PageHighMem(page))
-		gfp_mask |= __GFP_HIGHMEM;
-
-	if (PageHuge(page)) {
-		struct hstate *h = page_hstate(page);
-		struct alloc_control ac = {
-			.nid = nid,
-			.nmask = NULL,
-			.gfp_mask = __GFP_NOWARN,
-			.skip_cma = true,
-		};
-
-		return alloc_huge_page_nodemask(h, &ac);
-	}
-
-	if (PageTransHuge(page)) {
-		struct page *thp;
-		/*
-		 * ignore allocation failure warnings
-		 */
-		gfp_t thp_gfpmask = GFP_TRANSHUGE | __GFP_NOWARN;
-
-		/*
-		 * Remove the movable mask so that we don't allocate from
-		 * CMA area again.
-		 */
-		thp_gfpmask &= ~__GFP_MOVABLE;
-		thp = __alloc_pages_node(nid, thp_gfpmask, HPAGE_PMD_ORDER);
-		if (!thp)
-			return NULL;
-		prep_transhuge_page(thp);
-		return thp;
-	}
+	struct alloc_control __ac = {
+		.nid = page_to_nid(page),
+		.gfp_mask = GFP_USER | __GFP_NOWARN,
+		.skip_cma = true,
+	};
 
-	return __alloc_pages_node(nid, gfp_mask, 0);
+	return alloc_migration_target(page, &__ac);
 }
 
 static long check_and_migrate_cma_pages(struct task_struct *tsk,
@@ -1706,8 +1664,9 @@ static long check_and_migrate_cma_pages(struct task_struct *tsk,
 		for (i = 0; i < nr_pages; i++)
 			put_page(pages[i]);
 
-		if (migrate_pages(&cma_page_list, new_non_cma_page,
-				  NULL, NULL, MIGRATE_SYNC, MR_CONTIG_RANGE)) {
+		if (migrate_pages(&cma_page_list,
+				alloc_migration_target_non_cma, NULL, NULL,
+				MIGRATE_SYNC, MR_CONTIG_RANGE)) {
 			/*
 			 * some of the pages failed migration. Do get_user_pages
 			 * without migration.
-- 
2.7.4