mm: rename allocflags_to_migratetype for clarity

The page allocator has gfp flags (like __GFP_WAIT) and alloc flags (like
ALLOC_CPUSET) that have separate semantics.

The function allocflags_to_migratetype() actually takes gfp flags, not
alloc flags, and returns a migratetype.  Rename it to
gfpflags_to_migratetype().
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/gfp.h

@@ -156,7 +156,7 @@ struct vm_area_struct;
 #define GFP_DMA32	__GFP_DMA32
 
 /* Convert GFP flags to their corresponding migrate type */
-static inline int allocflags_to_migratetype(gfp_t gfp_flags)
+static inline int gfpflags_to_migratetype(const gfp_t gfp_flags)
 {
 	WARN_ON((gfp_flags & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK);
 

mm/compaction.c

@@ -1242,7 +1242,7 @@ static unsigned long compact_zone_order(struct zone *zone, int order,
 		.nr_freepages = 0,
 		.nr_migratepages = 0,
 		.order = order,
-		.migratetype = allocflags_to_migratetype(gfp_mask),
+		.migratetype = gfpflags_to_migratetype(gfp_mask),
 		.zone = zone,
 		.mode = mode,
 	};
@@ -1294,7 +1294,7 @@ unsigned long try_to_compact_pages(struct zonelist *zonelist,
 		return COMPACT_SKIPPED;
 
 #ifdef CONFIG_CMA
-	if (allocflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
+	if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
 		alloc_flags |= ALLOC_CMA;
 #endif
 	/* Compact each zone in the list */

mm/page_alloc.c

@@ -2523,7 +2523,7 @@ gfp_to_alloc_flags(gfp_t gfp_mask)
 			alloc_flags |= ALLOC_NO_WATERMARKS;
 	}
 #ifdef CONFIG_CMA
-	if (allocflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
+	if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
 		alloc_flags |= ALLOC_CMA;
 #endif
 	return alloc_flags;
@@ -2786,7 +2786,7 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
 	struct zone *preferred_zone;
 	struct zoneref *preferred_zoneref;
 	struct page *page = NULL;
-	int migratetype = allocflags_to_migratetype(gfp_mask);
+	int migratetype = gfpflags_to_migratetype(gfp_mask);
 	unsigned int cpuset_mems_cookie;
 	int alloc_flags = ALLOC_WMARK_LOW|ALLOC_CPUSET|ALLOC_FAIR;
 	int classzone_idx;