[RFC 15/16] mm/cma: remove ALLOC_CMA

[Joonsoo Kim]

Now, reserved pages for CMA are on ZONE_CMA and it only serves for
MIGRATE_MOVABLE. Therefore, we don't need to consider ALLOC_CMA at all.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
---
 mm/compaction.c |    4 ----
 mm/internal.h   |    3 +--
 mm/page_alloc.c |   16 ++--------------
 3 files changed, 3 insertions(+), 20 deletions(-)

diff --git a/mm/compaction.c b/mm/compaction.c
index f9792ba..b79134e 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1312,10 +1312,6 @@ unsigned long try_to_compact_pages(struct zonelist *zonelist,
 	if (!order || !may_enter_fs || !may_perform_io)
 		return COMPACT_SKIPPED;
 
-#ifdef CONFIG_CMA
-	if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
-		alloc_flags |= ALLOC_CMA;
-#endif
 	/* Compact each zone in the list */
 	for_each_zone_zonelist_nodemask(zone, z, zonelist, high_zoneidx,
 								nodemask) {
diff --git a/mm/internal.h b/mm/internal.h
index a4f90ba..9968dff 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -407,7 +407,6 @@ unsigned long reclaim_clean_pages_from_list(struct zone *zone,
 #define ALLOC_HARDER		0x10 /* try to alloc harder */
 #define ALLOC_HIGH		0x20 /* __GFP_HIGH set */
 #define ALLOC_CPUSET		0x40 /* check for correct cpuset */
-#define ALLOC_CMA		0x80 /* allow allocations from CMA areas */
-#define ALLOC_FAIR		0x100 /* fair zone allocation */
+#define ALLOC_FAIR		0x80 /* fair zone allocation */
 
 #endif	/* __MM_INTERNAL_H */
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index f2844f0..551cc5b 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1737,20 +1737,14 @@ static bool __zone_watermark_ok(struct zone *z, unsigned int order,
 	/* free_pages my go negative - that's OK */
 	long min = mark;
 	int o;
-	long free_cma = 0;
 
 	free_pages -= (1 << order) - 1;
 	if (alloc_flags & ALLOC_HIGH)
 		min -= min / 2;
 	if (alloc_flags & ALLOC_HARDER)
 		min -= min / 4;
-#ifdef CONFIG_CMA
-	/* If allocation can't use CMA areas don't use free CMA pages */
-	if (!(alloc_flags & ALLOC_CMA))
-		free_cma = zone_page_state(z, NR_FREE_CMA_PAGES);
-#endif
 
-	if (free_pages - free_cma <= min + z->lowmem_reserve[classzone_idx])
+	if (free_pages <= min + z->lowmem_reserve[classzone_idx])
 		return false;
 	for (o = 0; o < order; o++) {
 		/* At the next order, this order's pages become unavailable */
@@ -2550,10 +2544,7 @@ gfp_to_alloc_flags(gfp_t gfp_mask)
 				 unlikely(test_thread_flag(TIF_MEMDIE))))
 			alloc_flags |= ALLOC_NO_WATERMARKS;
 	}
-#ifdef CONFIG_CMA
-	if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE)
-		alloc_flags |= ALLOC_CMA;
-#endif
+
 	return alloc_flags;
 }
 
@@ -2837,9 +2828,6 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
 	if (unlikely(!zonelist->_zonerefs->zone))
 		return NULL;
 
-	if (IS_ENABLED(CONFIG_CMA) && migratetype == MIGRATE_MOVABLE)
-		alloc_flags |= ALLOC_CMA;
-
 retry_cpuset:
 	cpuset_mems_cookie = read_mems_allowed_begin();
 
-- 
1.7.9.5

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