Message-Id: <1461561670-28012-6-git-send-email-iamjoonsoo.kim@lge.com>
Date:	Mon, 25 Apr 2016 14:21:09 +0900
From:	js1304@...il.com
To:	Andrew Morton <akpm@...ux-foundation.org>
Cc:	Rik van Riel <riel@...hat.com>,
	Johannes Weiner <hannes@...xchg.org>,
	<mgorman@...hsingularity.net>,
	Laura Abbott <lauraa@...eaurora.org>,
	Minchan Kim <minchan@...nel.org>,
	Marek Szyprowski <m.szyprowski@...sung.com>,
	Michal Nazarewicz <mina86@...a86.com>,
	"Aneesh Kumar K.V" <aneesh.kumar@...ux.vnet.ibm.com>,
	Vlastimil Babka <vbabka@...e.cz>, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org, Joonsoo Kim <iamjoonsoo.kim@....com>
Subject: [PATCH v2 5/6] mm/cma: remove MIGRATE_CMA

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

Now, all reserved pages for CMA region are belong to the ZONE_CMA
and there is no other type of pages. Therefore, we don't need to
use MIGRATE_CMA to distinguish and handle differently for CMA pages
and ordinary pages. Remove MIGRATE_CMA.

Unfortunately, this patch make free CMA counter incorrect because
we count it when pages are on the MIGRATE_CMA. It will be fixed
by next patch. I can squash next patch here but it makes changes
complicated and hard to review so I separate that.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@....com>
---
 include/linux/gfp.h    |  3 +-
 include/linux/mmzone.h | 22 ------------
 include/linux/vmstat.h |  8 -----
 mm/cma.c               |  2 +-
 mm/compaction.c        | 10 ++----
 mm/hugetlb.c           |  2 +-
 mm/page_alloc.c        | 90 ++++++++++++++------------------------------------
 mm/page_isolation.c    |  5 ++-
 mm/vmstat.c            |  5 +--
 9 files changed, 32 insertions(+), 115 deletions(-)

diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index 4d6c008..1a3b869 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -559,8 +559,7 @@ static inline bool pm_suspended_storage(void)
 
 #if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA)
 /* The below functions must be run on a range from a single zone. */
-extern int alloc_contig_range(unsigned long start, unsigned long end,
-			      unsigned migratetype);
+extern int alloc_contig_range(unsigned long start, unsigned long end);
 extern void free_contig_range(unsigned long pfn, unsigned nr_pages);
 #endif
 
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 5c97ba9..75b41c5 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -41,22 +41,6 @@ enum {
 	MIGRATE_RECLAIMABLE,
 	MIGRATE_PCPTYPES,	/* the number of types on the pcp lists */
 	MIGRATE_HIGHATOMIC = MIGRATE_PCPTYPES,
-#ifdef CONFIG_CMA
-	/*
-	 * MIGRATE_CMA migration type is designed to mimic the way
-	 * ZONE_MOVABLE works.  Only movable pages can be allocated
-	 * from MIGRATE_CMA pageblocks and page allocator never
-	 * implicitly change migration type of MIGRATE_CMA pageblock.
-	 *
-	 * The way to use it is to change migratetype of a range of
-	 * pageblocks to MIGRATE_CMA which can be done by
-	 * __free_pageblock_cma() function.  What is important though
-	 * is that a range of pageblocks must be aligned to
-	 * MAX_ORDER_NR_PAGES should biggest page be bigger then
-	 * a single pageblock.
-	 */
-	MIGRATE_CMA,
-#endif
 #ifdef CONFIG_MEMORY_ISOLATION
 	MIGRATE_ISOLATE,	/* can't allocate from here */
 #endif
@@ -66,12 +50,6 @@ enum {
 /* In mm/page_alloc.c; keep in sync also with show_migration_types() there */
 extern char * const migratetype_names[MIGRATE_TYPES];
 
-#ifdef CONFIG_CMA
-#  define is_migrate_cma(migratetype) unlikely((migratetype) == MIGRATE_CMA)
-#else
-#  define is_migrate_cma(migratetype) false
-#endif
-
 #define for_each_migratetype_order(order, type) \
 	for (order = 0; order < MAX_ORDER; order++) \
 		for (type = 0; type < MIGRATE_TYPES; type++)
diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h
index 02fce41..6ddf080 100644
--- a/include/linux/vmstat.h
+++ b/include/linux/vmstat.h
@@ -260,14 +260,6 @@ static inline void drain_zonestat(struct zone *zone,
 			struct per_cpu_pageset *pset) { }
 #endif		/* CONFIG_SMP */
 
-static inline void __mod_zone_freepage_state(struct zone *zone, int nr_pages,
-					     int migratetype)
-{
-	__mod_zone_page_state(zone, NR_FREE_PAGES, nr_pages);
-	if (is_migrate_cma(migratetype))
-		__mod_zone_page_state(zone, NR_FREE_CMA_PAGES, nr_pages);
-}
-
 extern const char * const vmstat_text[];
 
 #endif /* _LINUX_VMSTAT_H */
diff --git a/mm/cma.c b/mm/cma.c
index 8684f50..bd436e4 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -444,7 +444,7 @@ struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align)
 
 		pfn = cma->base_pfn + (bitmap_no << cma->order_per_bit);
 		mutex_lock(&cma_mutex);
-		ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA);
+		ret = alloc_contig_range(pfn, pfn + count);
 		mutex_unlock(&cma_mutex);
 		if (ret == 0) {
 			page = pfn_to_page(pfn);
diff --git a/mm/compaction.c b/mm/compaction.c
index 315e5d5..91e0969 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -76,7 +76,7 @@ static void map_pages(struct list_head *list)
 
 static inline bool migrate_async_suitable(int migratetype)
 {
-	return is_migrate_cma(migratetype) || migratetype == MIGRATE_MOVABLE;
+	return migratetype == MIGRATE_MOVABLE;
 }
 
 #ifdef CONFIG_COMPACTION
@@ -965,7 +965,7 @@ static bool suitable_migration_target(struct page *page)
 			return false;
 	}
 
-	/* If the block is MIGRATE_MOVABLE or MIGRATE_CMA, allow migration */
+	/* If the block is MIGRATE_MOVABLE, allow migration */
 	if (migrate_async_suitable(get_pageblock_migratetype(page)))
 		return true;
 
@@ -1329,12 +1329,6 @@ static enum compact_result __compact_finished(struct zone *zone, struct compact_
 		if (!list_empty(&area->free_list[migratetype]))
 			return COMPACT_PARTIAL;
 
-#ifdef CONFIG_CMA
-		/* MIGRATE_MOVABLE can fallback on MIGRATE_CMA */
-		if (migratetype == MIGRATE_MOVABLE &&
-			!list_empty(&area->free_list[MIGRATE_CMA]))
-			return COMPACT_PARTIAL;
-#endif
 		/*
 		 * Job done if allocation would steal freepages from
 		 * other migratetype buddy lists.
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 949d806..b7ca28f 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1028,7 +1028,7 @@ static int __alloc_gigantic_page(unsigned long start_pfn,
 				unsigned long nr_pages)
 {
 	unsigned long end_pfn = start_pfn + nr_pages;
-	return alloc_contig_range(start_pfn, end_pfn, MIGRATE_MOVABLE);
+	return alloc_contig_range(start_pfn, end_pfn);
 }
 
 static bool pfn_range_valid_gigantic(struct zone *z,
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 69546b7..51b2b0c 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -124,8 +124,8 @@ gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK;
  * put on a pcplist. Used to avoid the pageblock migratetype lookup when
  * freeing from pcplists in most cases, at the cost of possibly becoming stale.
  * Also the migratetype set in the page does not necessarily match the pcplist
- * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
- * other index - this ensures that it will be put on the correct CMA freelist.
+ * index, e.g. page might have MIGRATE_MOVABLE set but be on a pcplist with any
+ * other index - this ensures that it will be put on the correct freelist.
  */
 static inline int get_pcppage_migratetype(struct page *page)
 {
@@ -234,9 +234,6 @@ char * const migratetype_names[MIGRATE_TYPES] = {
 	"Movable",
 	"Reclaimable",
 	"HighAtomic",
-#ifdef CONFIG_CMA
-	"CMA",
-#endif
 #ifdef CONFIG_MEMORY_ISOLATION
 	"Isolate",
 #endif
@@ -580,7 +577,7 @@ static inline void set_page_guard(struct zone *zone, struct page *page,
 	INIT_LIST_HEAD(&page->lru);
 	set_page_private(page, order);
 	/* Guard pages are not available for any usage */
-	__mod_zone_freepage_state(zone, -(1 << order), migratetype);
+	__mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << order));
 }
 
 static inline void clear_page_guard(struct zone *zone, struct page *page,
@@ -596,7 +593,7 @@ static inline void clear_page_guard(struct zone *zone, struct page *page,
 
 	set_page_private(page, 0);
 	if (!is_migrate_isolate(migratetype))
-		__mod_zone_freepage_state(zone, (1 << order), migratetype);
+		__mod_zone_page_state(zone, NR_FREE_PAGES, (1 << order));
 }
 #else
 struct page_ext_operations debug_guardpage_ops = { NULL, };
@@ -707,7 +704,7 @@ static inline void __free_one_page(struct page *page,
 
 	VM_BUG_ON(migratetype == -1);
 	if (likely(!is_migrate_isolate(migratetype)))
-		__mod_zone_freepage_state(zone, 1 << order, migratetype);
+		__mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order);
 
 	page_idx = pfn & ((1 << MAX_ORDER) - 1);
 
@@ -1416,7 +1413,7 @@ static void __init adjust_present_page_count(struct page *page, long count)
 	zone->present_pages += count;
 }
 
-/* Free whole pageblock and set its migration type to MIGRATE_CMA. */
+/* Free whole pageblock and set its migration type to MIGRATE_MOVABLE. */
 void __init init_cma_reserved_pageblock(struct page *page)
 {
 	unsigned i = pageblock_nr_pages;
@@ -1441,7 +1438,7 @@ void __init init_cma_reserved_pageblock(struct page *page)
 
 	adjust_present_page_count(page, pageblock_nr_pages);
 
-	set_pageblock_migratetype(page, MIGRATE_CMA);
+	set_pageblock_migratetype(page, MIGRATE_MOVABLE);
 
 	if (pageblock_order >= MAX_ORDER) {
 		i = pageblock_nr_pages;
@@ -1627,25 +1624,11 @@ static int fallbacks[MIGRATE_TYPES][4] = {
 	[MIGRATE_UNMOVABLE]   = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE,   MIGRATE_TYPES },
 	[MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE,   MIGRATE_MOVABLE,   MIGRATE_TYPES },
 	[MIGRATE_MOVABLE]     = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_TYPES },
-#ifdef CONFIG_CMA
-	[MIGRATE_CMA]         = { MIGRATE_TYPES }, /* Never used */
-#endif
 #ifdef CONFIG_MEMORY_ISOLATION
 	[MIGRATE_ISOLATE]     = { MIGRATE_TYPES }, /* Never used */
 #endif
 };
 
-#ifdef CONFIG_CMA
-static struct page *__rmqueue_cma_fallback(struct zone *zone,
-					unsigned int order)
-{
-	return __rmqueue_smallest(zone, order, MIGRATE_CMA);
-}
-#else
-static inline struct page *__rmqueue_cma_fallback(struct zone *zone,
-					unsigned int order) { return NULL; }
-#endif
-
 /*
  * Move the free pages in a range to the free lists of the requested type.
  * Note that start_page and end_pages are not aligned on a pageblock
@@ -1850,7 +1833,7 @@ static void reserve_highatomic_pageblock(struct page *page, struct zone *zone,
 	/* Yoink! */
 	mt = get_pageblock_migratetype(page);
 	if (mt != MIGRATE_HIGHATOMIC &&
-			!is_migrate_isolate(mt) && !is_migrate_cma(mt)) {
+			!is_migrate_isolate(mt)) {
 		zone->nr_reserved_highatomic += pageblock_nr_pages;
 		set_pageblock_migratetype(page, MIGRATE_HIGHATOMIC);
 		move_freepages_block(zone, page, MIGRATE_HIGHATOMIC);
@@ -1953,9 +1936,7 @@ __rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype)
 		/*
 		 * The pcppage_migratetype may differ from pageblock's
 		 * migratetype depending on the decisions in
-		 * find_suitable_fallback(). This is OK as long as it does not
-		 * differ for MIGRATE_CMA pageblocks. Those can be used as
-		 * fallback only via special __rmqueue_cma_fallback() function
+		 * find_suitable_fallback(). This is OK.
 		 */
 		set_pcppage_migratetype(page, start_migratetype);
 
@@ -1978,13 +1959,8 @@ static struct page *__rmqueue(struct zone *zone, unsigned int order,
 	struct page *page;
 
 	page = __rmqueue_smallest(zone, order, migratetype);
-	if (unlikely(!page)) {
-		if (migratetype == MIGRATE_MOVABLE)
-			page = __rmqueue_cma_fallback(zone, order);
-
-		if (!page)
-			page = __rmqueue_fallback(zone, order, migratetype);
-	}
+	if (unlikely(!page))
+		page = __rmqueue_fallback(zone, order, migratetype);
 
 	trace_mm_page_alloc_zone_locked(page, order, migratetype);
 	return page;
@@ -2021,9 +1997,6 @@ static int rmqueue_bulk(struct zone *zone, unsigned int order,
 		else
 			list_add_tail(&page->lru, list);
 		list = &page->lru;
-		if (is_migrate_cma(get_pcppage_migratetype(page)))
-			__mod_zone_page_state(zone, NR_FREE_CMA_PAGES,
-					      -(1 << order));
 	}
 	__mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
 	spin_unlock(&zone->lock);
@@ -2321,7 +2294,7 @@ int __isolate_free_page(struct page *page, unsigned int order)
 		if (!zone_watermark_ok(zone, 0, watermark, 0, 0))
 			return 0;
 
-		__mod_zone_freepage_state(zone, -(1UL << order), mt);
+		__mod_zone_page_state(zone, NR_FREE_PAGES, -(1UL << order));
 	}
 
 	/* Remove page from free list */
@@ -2336,7 +2309,7 @@ int __isolate_free_page(struct page *page, unsigned int order)
 		struct page *endpage = page + (1 << order) - 1;
 		for (; page < endpage; page += pageblock_nr_pages) {
 			int mt = get_pageblock_migratetype(page);
-			if (!is_migrate_isolate(mt) && !is_migrate_cma(mt))
+			if (!is_migrate_isolate(mt))
 				set_pageblock_migratetype(page,
 							  MIGRATE_MOVABLE);
 		}
@@ -2391,8 +2364,7 @@ alloc_pages_zone(struct zone *zone, unsigned int order, int migratetype)
 	if (!page)
 		return NULL;
 
-	__mod_zone_freepage_state(zone, -(1 << order),
-					  get_pcppage_migratetype(page));
+	__mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << order));
 
 	set_page_owner(page, order, __GFP_MOVABLE);
 	set_page_refcounted(page);
@@ -2453,8 +2425,7 @@ struct page *buffered_rmqueue(struct zone *preferred_zone,
 		spin_unlock(&zone->lock);
 		if (!page)
 			goto failed;
-		__mod_zone_freepage_state(zone, -(1 << order),
-					  get_pcppage_migratetype(page));
+		__mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << order));
 	}
 
 	__mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order));
@@ -2609,11 +2580,6 @@ static bool __zone_watermark_ok(struct zone *z, unsigned int order,
 			if (!list_empty(&area->free_list[mt]))
 				return true;
 		}
-
-#ifdef CONFIG_CMA
-		if (!list_empty(&area->free_list[MIGRATE_CMA]))
-			return true;
-#endif
 	}
 	return false;
 }
@@ -4073,9 +4039,6 @@ static void show_migration_types(unsigned char type)
 		[MIGRATE_MOVABLE]	= 'M',
 		[MIGRATE_RECLAIMABLE]	= 'E',
 		[MIGRATE_HIGHATOMIC]	= 'H',
-#ifdef CONFIG_CMA
-		[MIGRATE_CMA]		= 'C',
-#endif
 #ifdef CONFIG_MEMORY_ISOLATION
 		[MIGRATE_ISOLATE]	= 'I',
 #endif
@@ -7102,7 +7065,7 @@ bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
 		return false;
 
 	mt = get_pageblock_migratetype(page);
-	if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt))
+	if (mt == MIGRATE_MOVABLE)
 		return false;
 
 	pfn = page_to_pfn(page);
@@ -7250,15 +7213,11 @@ static int __alloc_contig_migrate_range(struct compact_control *cc,
  * alloc_contig_range() -- tries to allocate given range of pages
  * @start:	start PFN to allocate
  * @end:	one-past-the-last PFN to allocate
- * @migratetype:	migratetype of the underlaying pageblocks (either
- *			#MIGRATE_MOVABLE or #MIGRATE_CMA).  All pageblocks
- *			in range must have the same migratetype and it must
- *			be either of the two.
  *
  * The PFN range does not have to be pageblock or MAX_ORDER_NR_PAGES
  * aligned, however it's the caller's responsibility to guarantee that
  * we are the only thread that changes migrate type of pageblocks the
- * pages fall in.
+ * pages fall in and it should be MIGRATE_MOVABLE.
  *
  * The PFN range must belong to a single zone.
  *
@@ -7266,8 +7225,7 @@ static int __alloc_contig_migrate_range(struct compact_control *cc,
  * pages which PFN is in [start, end) are allocated for the caller and
  * need to be freed with free_contig_range().
  */
-int alloc_contig_range(unsigned long start, unsigned long end,
-		       unsigned migratetype)
+int alloc_contig_range(unsigned long start, unsigned long end)
 {
 	unsigned long outer_start, outer_end;
 	unsigned int order;
@@ -7300,14 +7258,14 @@ int alloc_contig_range(unsigned long start, unsigned long end,
 	 * allocator removing them from the buddy system.  This way
 	 * page allocator will never consider using them.
 	 *
-	 * This lets us mark the pageblocks back as
-	 * MIGRATE_CMA/MIGRATE_MOVABLE so that free pages in the
-	 * aligned range but not in the unaligned, original range are
-	 * put back to page allocator so that buddy can use them.
+	 * This lets us mark the pageblocks back as MIGRATE_MOVABLE
+	 * so that free pages in the aligned range but not in the
+	 * unaligned, original range are put back to page allocator
+	 * so that buddy can use them.
 	 */
 
 	ret = start_isolate_page_range(pfn_max_align_down(start),
-				       pfn_max_align_up(end), migratetype,
+				       pfn_max_align_up(end), MIGRATE_MOVABLE,
 				       false);
 	if (ret)
 		return ret;
@@ -7386,7 +7344,7 @@ int alloc_contig_range(unsigned long start, unsigned long end,
 
 done:
 	undo_isolate_page_range(pfn_max_align_down(start),
-				pfn_max_align_up(end), migratetype);
+				pfn_max_align_up(end), MIGRATE_MOVABLE);
 	return ret;
 }
 
diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index 612122b..5708649 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -61,13 +61,12 @@ static int set_migratetype_isolate(struct page *page,
 out:
 	if (!ret) {
 		unsigned long nr_pages;
-		int migratetype = get_pageblock_migratetype(page);
 
 		set_pageblock_migratetype(page, MIGRATE_ISOLATE);
 		zone->nr_isolate_pageblock++;
 		nr_pages = move_freepages_block(zone, page, MIGRATE_ISOLATE);
 
-		__mod_zone_freepage_state(zone, -nr_pages, migratetype);
+		__mod_zone_page_state(zone, NR_FREE_PAGES, -nr_pages);
 	}
 
 	spin_unlock_irqrestore(&zone->lock, flags);
@@ -122,7 +121,7 @@ static void unset_migratetype_isolate(struct page *page, unsigned migratetype)
 	 */
 	if (!isolated_page) {
 		nr_pages = move_freepages_block(zone, page, migratetype);
-		__mod_zone_freepage_state(zone, nr_pages, migratetype);
+		__mod_zone_page_state(zone, NR_FREE_PAGES, nr_pages);
 	}
 	set_pageblock_migratetype(page, migratetype);
 	zone->nr_isolate_pageblock--;
diff --git a/mm/vmstat.c b/mm/vmstat.c
index e8c46ad..39a0c3c 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1104,10 +1104,7 @@ static void pagetypeinfo_showmixedcount_print(struct seq_file *m,
 
 			page_mt = gfpflags_to_migratetype(page_ext->gfp_mask);
 			if (pageblock_mt != page_mt) {
-				if (is_migrate_cma(pageblock_mt))
-					count[MIGRATE_MOVABLE]++;
-				else
-					count[pageblock_mt]++;
+				count[pageblock_mt]++;
 
 				pfn = block_end_pfn;
 				break;
-- 
1.9.1

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