[PATCH v2 09/12] mm/migrate: make standard migration target allocation functions

[js1304@gmail.com]

From: Joonsoo Kim <iamjoonsoo.kim@lge.com>

There are some similar functions for migration target allocation. Since
there is no fundamental difference, it's better to keep just one rather
than keeping all variants. This patch implements base migration target
allocation function. In the following patches, variants will be converted
to use this function.

Note that PageHighmem() call in previous function is changed to open-code
"is_highmem_idx()" since it provides more readability.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
---
 include/linux/migrate.h |  6 +++---
 mm/memory-failure.c     |  3 ++-
 mm/memory_hotplug.c     |  3 ++-
 mm/migrate.c            | 24 +++++++++++++-----------
 mm/page_isolation.c     |  3 ++-
 5 files changed, 22 insertions(+), 17 deletions(-)

diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index 923c4f3..abf09b3 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -40,8 +40,8 @@ extern int migrate_page(struct address_space *mapping,
 			enum migrate_mode mode);
 extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free,
 		struct alloc_control *ac, enum migrate_mode mode, int reason);
-extern struct page *new_page_nodemask(struct page *page,
-		struct alloc_control *ac);
+extern struct page *alloc_migration_target(struct page *page,
+					struct alloc_control *ac);
 extern int isolate_movable_page(struct page *page, isolate_mode_t mode);
 extern void putback_movable_page(struct page *page);
 
@@ -60,7 +60,7 @@ static inline int migrate_pages(struct list_head *l, new_page_t new,
 			free_page_t free, struct alloc_control *ac,
 			enum migrate_mode mode, int reason)
 	{ return -ENOSYS; }
-static inline struct page *new_page_nodemask(struct page *page,
+static inline struct page *alloc_migration_target(struct page *page,
 		struct alloc_control *ac)
 	{ return NULL; }
 static inline int isolate_movable_page(struct page *page, isolate_mode_t mode)
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 0d5d59b..a75de67 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1639,9 +1639,10 @@ static struct page *new_page(struct page *p, struct alloc_control *__ac)
 	struct alloc_control ac = {
 		.nid = page_to_nid(p),
 		.nmask = &node_states[N_MEMORY],
+		.gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL,
 	};
 
-	return new_page_nodemask(p, &ac);
+	return alloc_migration_target(p, &ac);
 }
 
 /*
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 89642f9..185f4c9 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1249,7 +1249,8 @@ static struct page *new_node_page(struct page *page, struct alloc_control *__ac)
 
 	ac.nid = nid;
 	ac.nmask = &nmask;
-	return new_page_nodemask(page, &ac);
+	ac.gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL;
+	return alloc_migration_target(page, &ac);
 }
 
 static int
diff --git a/mm/migrate.c b/mm/migrate.c
index 9d6ed94..780135a 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1537,31 +1537,33 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
 	return rc;
 }
 
-struct page *new_page_nodemask(struct page *page, struct alloc_control *ac)
+struct page *alloc_migration_target(struct page *page, struct alloc_control *ac)
 {
-	gfp_t gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL;
 	unsigned int order = 0;
 	struct page *new_page = NULL;
+	int zidx;
 
+	/* hugetlb has it's own gfp handling logic */
 	if (PageHuge(page)) {
 		struct hstate *h = page_hstate(compound_head(page));
-		struct alloc_control __ac = {
-			.nid = ac->nid,
-			.nmask = ac->nmask,
-		};
 
-		return alloc_huge_page_nodemask(h, &__ac);
+		return alloc_huge_page_nodemask(h, ac);
 	}
 
+	ac->__gfp_mask = ac->gfp_mask;
 	if (PageTransHuge(page)) {
-		gfp_mask |= GFP_TRANSHUGE;
+		ac->__gfp_mask |= GFP_TRANSHUGE;
 		order = HPAGE_PMD_ORDER;
 	}
+	zidx = zone_idx(page_zone(page));
+	if (is_highmem_idx(zidx) || zidx == ZONE_MOVABLE)
+		ac->__gfp_mask |= __GFP_HIGHMEM;
 
-	if (PageHighMem(page) || (zone_idx(page_zone(page)) == ZONE_MOVABLE))
-		gfp_mask |= __GFP_HIGHMEM;
+	if (ac->skip_cma)
+		ac->__gfp_mask &= ~__GFP_MOVABLE;
 
-	new_page = __alloc_pages_nodemask(gfp_mask, order, ac->nid, ac->nmask);
+	new_page = __alloc_pages_nodemask(ac->__gfp_mask, order,
+					ac->nid, ac->nmask);
 
 	if (new_page && PageTransHuge(new_page))
 		prep_transhuge_page(new_page);
diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index 1e1828b..aba799d 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -303,7 +303,8 @@ struct page *alloc_migrate_target(struct page *page, struct alloc_control *__ac)
 	struct alloc_control ac = {
 		.nid = page_to_nid(page),
 		.nmask = &node_states[N_MEMORY],
+		.gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL,
 	};
 
-	return new_page_nodemask(page, &ac);
+	return alloc_migration_target(page, &ac);
 }
-- 
2.7.4