[RFC 16/16] mm/cma: remove MIGRATE_CMA

From: Joonsoo Kim
Date: Thu Feb 12 2015 - 02:31:40 EST


Now, reserved pages for CMA are only on ZONE_CMA so we don't need to
use MIGRATE_CMA to distiguish CMA freepages and handle it differently.
So, this patch removes MIGRATE_CMA and also remove all related code.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
---
include/linux/gfp.h | 3 +-
include/linux/mmzone.h | 23 --------------
include/linux/vmstat.h | 8 -----
mm/cma.c | 2 +-
mm/compaction.c | 2 +-
mm/hugetlb.c | 2 +-
mm/page_alloc.c | 79 ++++++++++++++----------------------------------
mm/page_isolation.c | 5 ++-
mm/vmstat.c | 4 ---
9 files changed, 28 insertions(+), 100 deletions(-)

diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index d125440..1a6a5e2 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -413,8 +413,7 @@ static inline bool pm_suspended_storage(void)
#ifdef 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);

/* CMA stuff */
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 991e20e..738b7f8 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -41,34 +41,12 @@ enum {
MIGRATE_MOVABLE,
MIGRATE_PCPTYPES, /* the number of types on the pcp lists */
MIGRATE_RESERVE = 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
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++)
@@ -156,7 +134,6 @@ enum zone_stat_item {
WORKINGSET_ACTIVATE,
WORKINGSET_NODERECLAIM,
NR_ANON_TRANSPARENT_HUGEPAGES,
- NR_FREE_CMA_PAGES,
NR_VM_ZONE_STAT_ITEMS };

/*
diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h
index 676488a..681f8ae 100644
--- a/include/linux/vmstat.h
+++ b/include/linux/vmstat.h
@@ -271,14 +271,6 @@ 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 b165c1a..46d3e79 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -405,7 +405,7 @@ struct page *cma_alloc(struct cma *cma, int 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 b79134e..1b9f18e 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -64,7 +64,7 @@ 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;
}

/*
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 9fd7227..2ba5802 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -706,7 +706,7 @@ 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(unsigned long start_pfn,
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 551cc5b..24c2ab5 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -571,7 +571,7 @@ static inline void __free_one_page(struct page *page,
*/
max_order = min(MAX_ORDER, pageblock_order + 1);
} else {
- __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);
@@ -592,8 +592,8 @@ static inline void __free_one_page(struct page *page,
clear_page_guard_flag(buddy);
set_page_private(buddy, 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 {
list_del(&buddy->lru);
@@ -815,7 +815,7 @@ 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(unsigned long pfn)
{
unsigned i = pageblock_nr_pages;
@@ -838,7 +838,7 @@ void __init init_cma_reserved_pageblock(unsigned long pfn)
mminit_verify_page_links(p, ZONE_CMA, nid, pfn);
} while (++p, ++pfn, --i);

- set_pageblock_migratetype(page, MIGRATE_CMA);
+ set_pageblock_migratetype(page, MIGRATE_MOVABLE);

if (pageblock_order >= MAX_ORDER) {
i = pageblock_nr_pages;
@@ -895,8 +895,8 @@ static inline void expand(struct zone *zone, struct page *page,
set_page_guard_flag(&page[size]);
set_page_private(&page[size], high);
/* Guard pages are not available for any usage */
- __mod_zone_freepage_state(zone, -(1 << high),
- migratetype);
+ __mod_zone_page_state(zone, NR_FREE_PAGES,
+ -(1 << high));
continue;
}
#endif
@@ -997,12 +997,7 @@ struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
static int fallbacks[MIGRATE_TYPES][4] = {
[MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
[MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
-#ifdef CONFIG_CMA
- [MIGRATE_MOVABLE] = { MIGRATE_CMA, MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
- [MIGRATE_CMA] = { MIGRATE_RESERVE }, /* Never used */
-#else
[MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
-#endif
[MIGRATE_RESERVE] = { MIGRATE_RESERVE }, /* Never used */
#ifdef CONFIG_MEMORY_ISOLATION
[MIGRATE_ISOLATE] = { MIGRATE_RESERVE }, /* Never used */
@@ -1095,10 +1090,6 @@ static void change_pageblock_range(struct page *pageblock_page,
* allocation list. If falling back for a reclaimable kernel allocation, be
* more aggressive about taking ownership of free pages.
*
- * On the other hand, never change migration type of MIGRATE_CMA pageblocks
- * nor move CMA pages to different free lists. We don't want unmovable pages
- * to be allocated from MIGRATE_CMA areas.
- *
* Returns the new migratetype of the pageblock (or the same old migratetype
* if it was unchanged).
*/
@@ -1107,15 +1098,6 @@ static int try_to_steal_freepages(struct zone *zone, struct page *page,
{
int current_order = page_order(page);

- /*
- * When borrowing from MIGRATE_CMA, we need to release the excess
- * buddy pages to CMA itself. We also ensure the freepage_migratetype
- * is set to CMA so it is returned to the correct freelist in case
- * the page ends up being not actually allocated from the pcp lists.
- */
- if (is_migrate_cma(fallback_type))
- return fallback_type;
-
/* Take ownership for orders >= pageblock_order */
if (current_order >= pageblock_order) {
change_pageblock_range(page, current_order, start_type);
@@ -1182,8 +1164,7 @@ __rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype)
new_type);
/* The freepage_migratetype may differ from pageblock's
* migratetype depending on the decisions in
- * try_to_steal_freepages. This is OK as long as it does
- * not differ for MIGRATE_CMA type.
+ * try_to_steal_freepages.
*/
set_freepage_migratetype(page, new_type);

@@ -1258,9 +1239,6 @@ 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_freepage_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);
@@ -1521,7 +1499,7 @@ 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 */
@@ -1534,7 +1512,7 @@ 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);
}
@@ -1626,8 +1604,7 @@ again:
spin_unlock(&zone->lock);
if (!page)
goto failed;
- __mod_zone_freepage_state(zone, -(1 << order),
- get_freepage_migratetype(page));
+ __mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << order));
}

__mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order));
@@ -3179,9 +3156,6 @@ static void show_migration_types(unsigned char type)
[MIGRATE_RECLAIMABLE] = 'E',
[MIGRATE_MOVABLE] = 'M',
[MIGRATE_RESERVE] = 'R',
-#ifdef CONFIG_CMA
- [MIGRATE_CMA] = 'C',
-#endif
#ifdef CONFIG_MEMORY_ISOLATION
[MIGRATE_ISOLATE] = 'I',
#endif
@@ -3233,8 +3207,7 @@ void show_free_areas(unsigned int filter)
" unevictable:%lu"
" dirty:%lu writeback:%lu unstable:%lu\n"
" free:%lu slab_reclaimable:%lu slab_unreclaimable:%lu\n"
- " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
- " free_cma:%lu\n",
+ " mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n",
global_page_state(NR_ACTIVE_ANON),
global_page_state(NR_INACTIVE_ANON),
global_page_state(NR_ISOLATED_ANON),
@@ -3251,8 +3224,7 @@ void show_free_areas(unsigned int filter)
global_page_state(NR_FILE_MAPPED),
global_page_state(NR_SHMEM),
global_page_state(NR_PAGETABLE),
- global_page_state(NR_BOUNCE),
- global_page_state(NR_FREE_CMA_PAGES));
+ global_page_state(NR_BOUNCE));

for_each_populated_zone(zone) {
int i;
@@ -3285,7 +3257,6 @@ void show_free_areas(unsigned int filter)
" pagetables:%lukB"
" unstable:%lukB"
" bounce:%lukB"
- " free_cma:%lukB"
" writeback_tmp:%lukB"
" pages_scanned:%lu"
" all_unreclaimable? %s"
@@ -3316,7 +3287,6 @@ void show_free_areas(unsigned int filter)
K(zone_page_state(zone, NR_PAGETABLE)),
K(zone_page_state(zone, NR_UNSTABLE_NFS)),
K(zone_page_state(zone, NR_BOUNCE)),
- K(zone_page_state(zone, NR_FREE_CMA_PAGES)),
K(zone_page_state(zone, NR_WRITEBACK_TEMP)),
K(zone_page_state(zone, NR_PAGES_SCANNED)),
(!zone_reclaimable(zone) ? "yes" : "no")
@@ -6224,7 +6194,7 @@ bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
if (zone_idx(zone) == ZONE_MOVABLE)
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);
@@ -6372,15 +6342,11 @@ 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.
*
@@ -6388,8 +6354,7 @@ 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;
int ret = 0, order;
@@ -6421,14 +6386,14 @@ 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;
@@ -6490,7 +6455,7 @@ 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 883e78d..bc1777a 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -57,13 +57,12 @@ int set_migratetype_isolate(struct page *page, bool skip_hwpoisoned_pages)
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);
@@ -116,7 +115,7 @@ 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 b362b8f..f3285d2 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -677,9 +677,6 @@ static char * const migratetype_names[MIGRATE_TYPES] = {
"Reclaimable",
"Movable",
"Reserve",
-#ifdef CONFIG_CMA
- "CMA",
-#endif
#ifdef CONFIG_MEMORY_ISOLATION
"Isolate",
#endif
@@ -801,7 +798,6 @@ const char * const vmstat_text[] = {
"workingset_activate",
"workingset_nodereclaim",
"nr_anon_transparent_hugepages",
- "nr_free_cma",

/* enum writeback_stat_item counters */
"nr_dirty_threshold",
--
1.7.9.5

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