Merge changes I2bb0954d,Icdbbebb9,I659b133b,Id51bc882,I59917adc,Ia67eaee0,I8e82434b,I1f112fa3 into msm-3.4
* changes:
mm: mmzone: MIGRATE_CMA migration type added
mm: page_alloc: change fallbacks array handling
mm: page_alloc: introduce alloc_contig_range()
mm: compaction: export some of the functions
mm: compaction: introduce isolate_freepages_range()
mm: compaction: introduce map_pages()
mm: compaction: introduce isolate_migratepages_range()
mm: page_alloc: remove trailing whitespace
diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index 581e74b..78d32a7 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -391,4 +391,15 @@
}
#endif /* CONFIG_PM_SLEEP */
+#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);
+extern void free_contig_range(unsigned long pfn, unsigned nr_pages);
+
+/* CMA stuff */
+extern void init_cma_reserved_pageblock(struct page *page);
+
+#endif
+
#endif /* __LINUX_GFP_H */
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 64290b3..f90965a 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -35,13 +35,37 @@
*/
#define PAGE_ALLOC_COSTLY_ORDER 3
-#define MIGRATE_UNMOVABLE 0
-#define MIGRATE_RECLAIMABLE 1
-#define MIGRATE_MOVABLE 2
-#define MIGRATE_PCPTYPES 3 /* the number of types on the pcp lists */
-#define MIGRATE_RESERVE 3
-#define MIGRATE_ISOLATE 4 /* can't allocate from here */
-#define MIGRATE_TYPES 5
+enum {
+ MIGRATE_UNMOVABLE,
+ MIGRATE_RECLAIMABLE,
+ 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
+ MIGRATE_ISOLATE, /* can't allocate from here */
+ 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++) \
diff --git a/mm/Kconfig b/mm/Kconfig
index cad244c..84489cd 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -198,7 +198,7 @@
config MIGRATION
bool "Page migration"
def_bool y
- depends on NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE || COMPACTION
+ depends on NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE || COMPACTION || CMA
help
Allows the migration of the physical location of pages of processes
while the virtual addresses are not changed. This is useful in
diff --git a/mm/Makefile b/mm/Makefile
index 50ec00e..8aada89 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -13,7 +13,7 @@
readahead.o swap.o truncate.o vmscan.o shmem.o \
prio_tree.o util.o mmzone.o vmstat.o backing-dev.o \
page_isolation.o mm_init.o mmu_context.o percpu.o \
- $(mmu-y)
+ compaction.o $(mmu-y)
obj-y += init-mm.o
ifdef CONFIG_NO_BOOTMEM
@@ -32,7 +32,6 @@
obj-$(CONFIG_SPARSEMEM) += sparse.o
obj-$(CONFIG_SPARSEMEM_VMEMMAP) += sparse-vmemmap.o
obj-$(CONFIG_SLOB) += slob.o
-obj-$(CONFIG_COMPACTION) += compaction.o
obj-$(CONFIG_MMU_NOTIFIER) += mmu_notifier.o
obj-$(CONFIG_KSM) += ksm.o
obj-$(CONFIG_PAGE_POISONING) += debug-pagealloc.o
diff --git a/mm/compaction.c b/mm/compaction.c
index 74a8c82..da7d35e 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -16,30 +16,11 @@
#include <linux/sysfs.h>
#include "internal.h"
+#if defined CONFIG_COMPACTION || defined CONFIG_CMA
+
#define CREATE_TRACE_POINTS
#include <trace/events/compaction.h>
-/*
- * compact_control is used to track pages being migrated and the free pages
- * they are being migrated to during memory compaction. The free_pfn starts
- * at the end of a zone and migrate_pfn begins at the start. Movable pages
- * are moved to the end of a zone during a compaction run and the run
- * completes when free_pfn <= migrate_pfn
- */
-struct compact_control {
- struct list_head freepages; /* List of free pages to migrate to */
- struct list_head migratepages; /* List of pages being migrated */
- unsigned long nr_freepages; /* Number of isolated free pages */
- unsigned long nr_migratepages; /* Number of pages to migrate */
- unsigned long free_pfn; /* isolate_freepages search base */
- unsigned long migrate_pfn; /* isolate_migratepages search base */
- bool sync; /* Synchronous migration */
-
- int order; /* order a direct compactor needs */
- int migratetype; /* MOVABLE, RECLAIMABLE etc */
- struct zone *zone;
-};
-
static unsigned long release_freepages(struct list_head *freelist)
{
struct page *page, *next;
@@ -54,24 +35,35 @@
return count;
}
-/* Isolate free pages onto a private freelist. Must hold zone->lock */
-static unsigned long isolate_freepages_block(struct zone *zone,
- unsigned long blockpfn,
- struct list_head *freelist)
+static void map_pages(struct list_head *list)
{
- unsigned long zone_end_pfn, end_pfn;
+ struct page *page;
+
+ list_for_each_entry(page, list, lru) {
+ arch_alloc_page(page, 0);
+ kernel_map_pages(page, 1, 1);
+ }
+}
+
+static inline bool migrate_async_suitable(int migratetype)
+{
+ return is_migrate_cma(migratetype) || migratetype == MIGRATE_MOVABLE;
+}
+
+/*
+ * Isolate free pages onto a private freelist. Caller must hold zone->lock.
+ * If @strict is true, will abort returning 0 on any invalid PFNs or non-free
+ * pages inside of the pageblock (even though it may still end up isolating
+ * some pages).
+ */
+static unsigned long isolate_freepages_block(unsigned long blockpfn,
+ unsigned long end_pfn,
+ struct list_head *freelist,
+ bool strict)
+{
int nr_scanned = 0, total_isolated = 0;
struct page *cursor;
- /* Get the last PFN we should scan for free pages at */
- zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages;
- end_pfn = min(blockpfn + pageblock_nr_pages, zone_end_pfn);
-
- /* Find the first usable PFN in the block to initialse page cursor */
- for (; blockpfn < end_pfn; blockpfn++) {
- if (pfn_valid_within(blockpfn))
- break;
- }
cursor = pfn_to_page(blockpfn);
/* Isolate free pages. This assumes the block is valid */
@@ -79,15 +71,23 @@
int isolated, i;
struct page *page = cursor;
- if (!pfn_valid_within(blockpfn))
+ if (!pfn_valid_within(blockpfn)) {
+ if (strict)
+ return 0;
continue;
+ }
nr_scanned++;
- if (!PageBuddy(page))
+ if (!PageBuddy(page)) {
+ if (strict)
+ return 0;
continue;
+ }
/* Found a free page, break it into order-0 pages */
isolated = split_free_page(page);
+ if (!isolated && strict)
+ return 0;
total_isolated += isolated;
for (i = 0; i < isolated; i++) {
list_add(&page->lru, freelist);
@@ -105,114 +105,71 @@
return total_isolated;
}
-/* Returns true if the page is within a block suitable for migration to */
-static bool suitable_migration_target(struct page *page)
-{
-
- int migratetype = get_pageblock_migratetype(page);
-
- /* Don't interfere with memory hot-remove or the min_free_kbytes blocks */
- if (migratetype == MIGRATE_ISOLATE || migratetype == MIGRATE_RESERVE)
- return false;
-
- /* If the page is a large free page, then allow migration */
- if (PageBuddy(page) && page_order(page) >= pageblock_order)
- return true;
-
- /* If the block is MIGRATE_MOVABLE, allow migration */
- if (migratetype == MIGRATE_MOVABLE)
- return true;
-
- /* Otherwise skip the block */
- return false;
-}
-
-/*
- * Based on information in the current compact_control, find blocks
- * suitable for isolating free pages from and then isolate them.
+/**
+ * isolate_freepages_range() - isolate free pages.
+ * @start_pfn: The first PFN to start isolating.
+ * @end_pfn: The one-past-last PFN.
+ *
+ * Non-free pages, invalid PFNs, or zone boundaries within the
+ * [start_pfn, end_pfn) range are considered errors, cause function to
+ * undo its actions and return zero.
+ *
+ * Otherwise, function returns one-past-the-last PFN of isolated page
+ * (which may be greater then end_pfn if end fell in a middle of
+ * a free page).
*/
-static void isolate_freepages(struct zone *zone,
- struct compact_control *cc)
+unsigned long
+isolate_freepages_range(unsigned long start_pfn, unsigned long end_pfn)
{
- struct page *page;
- unsigned long high_pfn, low_pfn, pfn;
- unsigned long flags;
- int nr_freepages = cc->nr_freepages;
- struct list_head *freelist = &cc->freepages;
+ unsigned long isolated, pfn, block_end_pfn, flags;
+ struct zone *zone = NULL;
+ LIST_HEAD(freelist);
- /*
- * Initialise the free scanner. The starting point is where we last
- * scanned from (or the end of the zone if starting). The low point
- * is the end of the pageblock the migration scanner is using.
- */
- pfn = cc->free_pfn;
- low_pfn = cc->migrate_pfn + pageblock_nr_pages;
+ if (pfn_valid(start_pfn))
+ zone = page_zone(pfn_to_page(start_pfn));
- /*
- * Take care that if the migration scanner is at the end of the zone
- * that the free scanner does not accidentally move to the next zone
- * in the next isolation cycle.
- */
- high_pfn = min(low_pfn, pfn);
-
- /*
- * Isolate free pages until enough are available to migrate the
- * pages on cc->migratepages. We stop searching if the migrate
- * and free page scanners meet or enough free pages are isolated.
- */
- for (; pfn > low_pfn && cc->nr_migratepages > nr_freepages;
- pfn -= pageblock_nr_pages) {
- unsigned long isolated;
-
- if (!pfn_valid(pfn))
- continue;
+ for (pfn = start_pfn; pfn < end_pfn; pfn += isolated) {
+ if (!pfn_valid(pfn) || zone != page_zone(pfn_to_page(pfn)))
+ break;
/*
- * Check for overlapping nodes/zones. It's possible on some
- * configurations to have a setup like
- * node0 node1 node0
- * i.e. it's possible that all pages within a zones range of
- * pages do not belong to a single zone.
+ * On subsequent iterations ALIGN() is actually not needed,
+ * but we keep it that we not to complicate the code.
*/
- page = pfn_to_page(pfn);
- if (page_zone(page) != zone)
- continue;
+ block_end_pfn = ALIGN(pfn + 1, pageblock_nr_pages);
+ block_end_pfn = min(block_end_pfn, end_pfn);
- /* Check the block is suitable for migration */
- if (!suitable_migration_target(page))
- continue;
-
- /*
- * Found a block suitable for isolating free pages from. Now
- * we disabled interrupts, double check things are ok and
- * isolate the pages. This is to minimise the time IRQs
- * are disabled
- */
- isolated = 0;
spin_lock_irqsave(&zone->lock, flags);
- if (suitable_migration_target(page)) {
- isolated = isolate_freepages_block(zone, pfn, freelist);
- nr_freepages += isolated;
- }
+ isolated = isolate_freepages_block(pfn, block_end_pfn,
+ &freelist, true);
spin_unlock_irqrestore(&zone->lock, flags);
/*
- * Record the highest PFN we isolated pages from. When next
- * looking for free pages, the search will restart here as
- * page migration may have returned some pages to the allocator
+ * In strict mode, isolate_freepages_block() returns 0 if
+ * there are any holes in the block (ie. invalid PFNs or
+ * non-free pages).
*/
- if (isolated)
- high_pfn = max(high_pfn, pfn);
+ if (!isolated)
+ break;
+
+ /*
+ * If we managed to isolate pages, it is always (1 << n) *
+ * pageblock_nr_pages for some non-negative n. (Max order
+ * page may span two pageblocks).
+ */
}
/* split_free_page does not map the pages */
- list_for_each_entry(page, freelist, lru) {
- arch_alloc_page(page, 0);
- kernel_map_pages(page, 1, 1);
+ map_pages(&freelist);
+
+ if (pfn < end_pfn) {
+ /* Loop terminated early, cleanup. */
+ release_freepages(&freelist);
+ return 0;
}
- cc->free_pfn = high_pfn;
- cc->nr_freepages = nr_freepages;
+ /* We don't use freelists for anything. */
+ return pfn;
}
/* Update the number of anon and file isolated pages in the zone */
@@ -243,38 +200,34 @@
return isolated > (inactive + active) / 2;
}
-/* possible outcome of isolate_migratepages */
-typedef enum {
- ISOLATE_ABORT, /* Abort compaction now */
- ISOLATE_NONE, /* No pages isolated, continue scanning */
- ISOLATE_SUCCESS, /* Pages isolated, migrate */
-} isolate_migrate_t;
-
-/*
- * Isolate all pages that can be migrated from the block pointed to by
- * the migrate scanner within compact_control.
+/**
+ * isolate_migratepages_range() - isolate all migrate-able pages in range.
+ * @zone: Zone pages are in.
+ * @cc: Compaction control structure.
+ * @low_pfn: The first PFN of the range.
+ * @end_pfn: The one-past-the-last PFN of the range.
+ *
+ * Isolate all pages that can be migrated from the range specified by
+ * [low_pfn, end_pfn). Returns zero if there is a fatal signal
+ * pending), otherwise PFN of the first page that was not scanned
+ * (which may be both less, equal to or more then end_pfn).
+ *
+ * Assumes that cc->migratepages is empty and cc->nr_migratepages is
+ * zero.
+ *
+ * Apart from cc->migratepages and cc->nr_migratetypes this function
+ * does not modify any cc's fields, in particular it does not modify
+ * (or read for that matter) cc->migrate_pfn.
*/
-static isolate_migrate_t isolate_migratepages(struct zone *zone,
- struct compact_control *cc)
+unsigned long
+isolate_migratepages_range(struct zone *zone, struct compact_control *cc,
+ unsigned long low_pfn, unsigned long end_pfn)
{
- unsigned long low_pfn, end_pfn;
unsigned long last_pageblock_nr = 0, pageblock_nr;
unsigned long nr_scanned = 0, nr_isolated = 0;
struct list_head *migratelist = &cc->migratepages;
isolate_mode_t mode = ISOLATE_ACTIVE|ISOLATE_INACTIVE;
- /* Do not scan outside zone boundaries */
- low_pfn = max(cc->migrate_pfn, zone->zone_start_pfn);
-
- /* Only scan within a pageblock boundary */
- end_pfn = ALIGN(low_pfn + pageblock_nr_pages, pageblock_nr_pages);
-
- /* Do not cross the free scanner or scan within a memory hole */
- if (end_pfn > cc->free_pfn || !pfn_valid(low_pfn)) {
- cc->migrate_pfn = end_pfn;
- return ISOLATE_NONE;
- }
-
/*
* Ensure that there are not too many pages isolated from the LRU
* list by either parallel reclaimers or compaction. If there are,
@@ -283,12 +236,12 @@
while (unlikely(too_many_isolated(zone))) {
/* async migration should just abort */
if (!cc->sync)
- return ISOLATE_ABORT;
+ return 0;
congestion_wait(BLK_RW_ASYNC, HZ/10);
if (fatal_signal_pending(current))
- return ISOLATE_ABORT;
+ return 0;
}
/* Time to isolate some pages for migration */
@@ -351,7 +304,7 @@
*/
pageblock_nr = low_pfn >> pageblock_order;
if (!cc->sync && last_pageblock_nr != pageblock_nr &&
- get_pageblock_migratetype(page) != MIGRATE_MOVABLE) {
+ !migrate_async_suitable(get_pageblock_migratetype(page))) {
low_pfn += pageblock_nr_pages;
low_pfn = ALIGN(low_pfn, pageblock_nr_pages) - 1;
last_pageblock_nr = pageblock_nr;
@@ -396,11 +349,124 @@
acct_isolated(zone, cc);
spin_unlock_irq(&zone->lru_lock);
- cc->migrate_pfn = low_pfn;
trace_mm_compaction_isolate_migratepages(nr_scanned, nr_isolated);
- return ISOLATE_SUCCESS;
+ return low_pfn;
+}
+
+#endif /* CONFIG_COMPACTION || CONFIG_CMA */
+#ifdef CONFIG_COMPACTION
+
+/* Returns true if the page is within a block suitable for migration to */
+static bool suitable_migration_target(struct page *page)
+{
+
+ int migratetype = get_pageblock_migratetype(page);
+
+ /* Don't interfere with memory hot-remove or the min_free_kbytes blocks */
+ if (migratetype == MIGRATE_ISOLATE || migratetype == MIGRATE_RESERVE)
+ return false;
+
+ /* If the page is a large free page, then allow migration */
+ if (PageBuddy(page) && page_order(page) >= pageblock_order)
+ return true;
+
+ /* If the block is MIGRATE_MOVABLE or MIGRATE_CMA, allow migration */
+ if (migrate_async_suitable(migratetype))
+ return true;
+
+ /* Otherwise skip the block */
+ return false;
+}
+
+/*
+ * Based on information in the current compact_control, find blocks
+ * suitable for isolating free pages from and then isolate them.
+ */
+static void isolate_freepages(struct zone *zone,
+ struct compact_control *cc)
+{
+ struct page *page;
+ unsigned long high_pfn, low_pfn, pfn, zone_end_pfn, end_pfn;
+ unsigned long flags;
+ int nr_freepages = cc->nr_freepages;
+ struct list_head *freelist = &cc->freepages;
+
+ /*
+ * Initialise the free scanner. The starting point is where we last
+ * scanned from (or the end of the zone if starting). The low point
+ * is the end of the pageblock the migration scanner is using.
+ */
+ pfn = cc->free_pfn;
+ low_pfn = cc->migrate_pfn + pageblock_nr_pages;
+
+ /*
+ * Take care that if the migration scanner is at the end of the zone
+ * that the free scanner does not accidentally move to the next zone
+ * in the next isolation cycle.
+ */
+ high_pfn = min(low_pfn, pfn);
+
+ zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages;
+
+ /*
+ * Isolate free pages until enough are available to migrate the
+ * pages on cc->migratepages. We stop searching if the migrate
+ * and free page scanners meet or enough free pages are isolated.
+ */
+ for (; pfn > low_pfn && cc->nr_migratepages > nr_freepages;
+ pfn -= pageblock_nr_pages) {
+ unsigned long isolated;
+
+ if (!pfn_valid(pfn))
+ continue;
+
+ /*
+ * Check for overlapping nodes/zones. It's possible on some
+ * configurations to have a setup like
+ * node0 node1 node0
+ * i.e. it's possible that all pages within a zones range of
+ * pages do not belong to a single zone.
+ */
+ page = pfn_to_page(pfn);
+ if (page_zone(page) != zone)
+ continue;
+
+ /* Check the block is suitable for migration */
+ if (!suitable_migration_target(page))
+ continue;
+
+ /*
+ * Found a block suitable for isolating free pages from. Now
+ * we disabled interrupts, double check things are ok and
+ * isolate the pages. This is to minimise the time IRQs
+ * are disabled
+ */
+ isolated = 0;
+ spin_lock_irqsave(&zone->lock, flags);
+ if (suitable_migration_target(page)) {
+ end_pfn = min(pfn + pageblock_nr_pages, zone_end_pfn);
+ isolated = isolate_freepages_block(pfn, end_pfn,
+ freelist, false);
+ nr_freepages += isolated;
+ }
+ spin_unlock_irqrestore(&zone->lock, flags);
+
+ /*
+ * Record the highest PFN we isolated pages from. When next
+ * looking for free pages, the search will restart here as
+ * page migration may have returned some pages to the allocator
+ */
+ if (isolated)
+ high_pfn = max(high_pfn, pfn);
+ }
+
+ /* split_free_page does not map the pages */
+ map_pages(freelist);
+
+ cc->free_pfn = high_pfn;
+ cc->nr_freepages = nr_freepages;
}
/*
@@ -449,6 +515,44 @@
cc->nr_freepages = nr_freepages;
}
+/* possible outcome of isolate_migratepages */
+typedef enum {
+ ISOLATE_ABORT, /* Abort compaction now */
+ ISOLATE_NONE, /* No pages isolated, continue scanning */
+ ISOLATE_SUCCESS, /* Pages isolated, migrate */
+} isolate_migrate_t;
+
+/*
+ * Isolate all pages that can be migrated from the block pointed to by
+ * the migrate scanner within compact_control.
+ */
+static isolate_migrate_t isolate_migratepages(struct zone *zone,
+ struct compact_control *cc)
+{
+ unsigned long low_pfn, end_pfn;
+
+ /* Do not scan outside zone boundaries */
+ low_pfn = max(cc->migrate_pfn, zone->zone_start_pfn);
+
+ /* Only scan within a pageblock boundary */
+ end_pfn = ALIGN(low_pfn + pageblock_nr_pages, pageblock_nr_pages);
+
+ /* Do not cross the free scanner or scan within a memory hole */
+ if (end_pfn > cc->free_pfn || !pfn_valid(low_pfn)) {
+ cc->migrate_pfn = end_pfn;
+ return ISOLATE_NONE;
+ }
+
+ /* Perform the isolation */
+ low_pfn = isolate_migratepages_range(zone, cc, low_pfn, end_pfn);
+ if (!low_pfn)
+ return ISOLATE_ABORT;
+
+ cc->migrate_pfn = low_pfn;
+
+ return ISOLATE_SUCCESS;
+}
+
static int compact_finished(struct zone *zone,
struct compact_control *cc)
{
@@ -795,3 +899,5 @@
return device_remove_file(&node->dev, &dev_attr_compact);
}
#endif /* CONFIG_SYSFS && CONFIG_NUMA */
+
+#endif /* CONFIG_COMPACTION */
diff --git a/mm/internal.h b/mm/internal.h
index 2189af4..aee4761 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -100,6 +100,39 @@
extern bool is_free_buddy_page(struct page *page);
#endif
+#if defined CONFIG_COMPACTION || defined CONFIG_CMA
+
+/*
+ * in mm/compaction.c
+ */
+/*
+ * compact_control is used to track pages being migrated and the free pages
+ * they are being migrated to during memory compaction. The free_pfn starts
+ * at the end of a zone and migrate_pfn begins at the start. Movable pages
+ * are moved to the end of a zone during a compaction run and the run
+ * completes when free_pfn <= migrate_pfn
+ */
+struct compact_control {
+ struct list_head freepages; /* List of free pages to migrate to */
+ struct list_head migratepages; /* List of pages being migrated */
+ unsigned long nr_freepages; /* Number of isolated free pages */
+ unsigned long nr_migratepages; /* Number of pages to migrate */
+ unsigned long free_pfn; /* isolate_freepages search base */
+ unsigned long migrate_pfn; /* isolate_migratepages search base */
+ bool sync; /* Synchronous migration */
+
+ int order; /* order a direct compactor needs */
+ int migratetype; /* MOVABLE, RECLAIMABLE etc */
+ struct zone *zone;
+};
+
+unsigned long
+isolate_freepages_range(unsigned long start_pfn, unsigned long end_pfn);
+unsigned long
+isolate_migratepages_range(struct zone *zone, struct compact_control *cc,
+ unsigned long low_pfn, unsigned long end_pfn);
+
+#endif
/*
* function for dealing with page's order in buddy system.
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index d5d8541..5eeace2 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -57,6 +57,7 @@
#include <linux/ftrace_event.h>
#include <linux/memcontrol.h>
#include <linux/prefetch.h>
+#include <linux/migrate.h>
#include <linux/page-debug-flags.h>
#include <asm/tlbflush.h>
@@ -520,10 +521,10 @@
* free pages of length of (1 << order) and marked with _mapcount -2. Page's
* order is recorded in page_private(page) field.
* So when we are allocating or freeing one, we can derive the state of the
- * other. That is, if we allocate a small block, and both were
- * free, the remainder of the region must be split into blocks.
+ * other. That is, if we allocate a small block, and both were
+ * free, the remainder of the region must be split into blocks.
* If a block is freed, and its buddy is also free, then this
- * triggers coalescing into a block of larger size.
+ * triggers coalescing into a block of larger size.
*
* -- wli
*/
@@ -756,6 +757,24 @@
__free_pages(page, order);
}
+#ifdef CONFIG_CMA
+/* Free whole pageblock and set it's migration type to MIGRATE_CMA. */
+void __init init_cma_reserved_pageblock(struct page *page)
+{
+ unsigned i = pageblock_nr_pages;
+ struct page *p = page;
+
+ do {
+ __ClearPageReserved(p);
+ set_page_count(p, 0);
+ } while (++p, --i);
+
+ set_page_refcounted(page);
+ set_pageblock_migratetype(page, MIGRATE_CMA);
+ __free_pages(page, pageblock_order);
+ totalram_pages += pageblock_nr_pages;
+}
+#endif
/*
* The order of subdivision here is critical for the IO subsystem.
@@ -881,11 +900,17 @@
* This array describes the order lists are fallen back to when
* the free lists for the desirable migrate type are depleted
*/
-static int fallbacks[MIGRATE_TYPES][MIGRATE_TYPES-1] = {
- [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
- [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE },
- [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
- [MIGRATE_RESERVE] = { MIGRATE_RESERVE, MIGRATE_RESERVE, MIGRATE_RESERVE }, /* Never used */
+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 */
+ [MIGRATE_ISOLATE] = { MIGRATE_RESERVE }, /* Never used */
};
/*
@@ -980,12 +1005,12 @@
/* Find the largest possible block of pages in the other list */
for (current_order = MAX_ORDER-1; current_order >= order;
--current_order) {
- for (i = 0; i < MIGRATE_TYPES - 1; i++) {
+ for (i = 0;; i++) {
migratetype = fallbacks[start_migratetype][i];
/* MIGRATE_RESERVE handled later if necessary */
if (migratetype == MIGRATE_RESERVE)
- continue;
+ break;
area = &(zone->free_area[current_order]);
if (list_empty(&area->free_list[migratetype]))
@@ -1000,11 +1025,18 @@
* pages to the preferred 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 on different free lists. We don't
+ * want unmovable pages to be allocated from
+ * MIGRATE_CMA areas.
*/
- if (unlikely(current_order >= (pageblock_order >> 1)) ||
- start_migratetype == MIGRATE_RECLAIMABLE ||
- page_group_by_mobility_disabled) {
- unsigned long pages;
+ if (!is_migrate_cma(migratetype) &&
+ (unlikely(current_order >= pageblock_order / 2) ||
+ start_migratetype == MIGRATE_RECLAIMABLE ||
+ page_group_by_mobility_disabled)) {
+ int pages;
pages = move_freepages_block(zone, page,
start_migratetype);
@@ -1022,11 +1054,14 @@
rmv_page_order(page);
/* Take ownership for orders >= pageblock_order */
- if (current_order >= pageblock_order)
+ if (current_order >= pageblock_order &&
+ !is_migrate_cma(migratetype))
change_pageblock_range(page, current_order,
start_migratetype);
- expand(zone, page, order, current_order, area, migratetype);
+ expand(zone, page, order, current_order, area,
+ is_migrate_cma(migratetype)
+ ? migratetype : start_migratetype);
trace_mm_page_alloc_extfrag(page, order, current_order,
start_migratetype, migratetype);
@@ -1068,17 +1103,17 @@
return page;
}
-/*
+/*
* Obtain a specified number of elements from the buddy allocator, all under
* a single hold of the lock, for efficiency. Add them to the supplied list.
* Returns the number of new pages which were placed at *list.
*/
-static int rmqueue_bulk(struct zone *zone, unsigned int order,
+static int rmqueue_bulk(struct zone *zone, unsigned int order,
unsigned long count, struct list_head *list,
int migratetype, int cold)
{
- int i;
-
+ int mt = migratetype, i;
+
spin_lock(&zone->lock);
for (i = 0; i < count; ++i) {
struct page *page = __rmqueue(zone, order, migratetype);
@@ -1098,7 +1133,12 @@
list_add(&page->lru, list);
else
list_add_tail(&page->lru, list);
- set_page_private(page, migratetype);
+ if (IS_ENABLED(CONFIG_CMA)) {
+ mt = get_pageblock_migratetype(page);
+ if (!is_migrate_cma(mt) && mt != MIGRATE_ISOLATE)
+ mt = migratetype;
+ }
+ set_page_private(page, mt);
list = &page->lru;
}
__mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order));
@@ -1378,8 +1418,12 @@
if (order >= pageblock_order - 1) {
struct page *endpage = page + (1 << order) - 1;
- for (; page < endpage; page += pageblock_nr_pages)
- set_pageblock_migratetype(page, MIGRATE_MOVABLE);
+ for (; page < endpage; page += pageblock_nr_pages) {
+ int mt = get_pageblock_migratetype(page);
+ if (mt != MIGRATE_ISOLATE && !is_migrate_cma(mt))
+ set_pageblock_migratetype(page,
+ MIGRATE_MOVABLE);
+ }
}
return 1 << order;
@@ -4309,7 +4353,7 @@
init_waitqueue_head(&pgdat->kswapd_wait);
pgdat->kswapd_max_order = 0;
pgdat_page_cgroup_init(pgdat);
-
+
for (j = 0; j < MAX_NR_ZONES; j++) {
struct zone *zone = pgdat->node_zones + j;
unsigned long size, realsize, memmap_pages;
@@ -5423,14 +5467,16 @@
__count_immobile_pages(struct zone *zone, struct page *page, int count)
{
unsigned long pfn, iter, found;
+ int mt;
+
/*
* For avoiding noise data, lru_add_drain_all() should be called
* If ZONE_MOVABLE, the zone never contains immobile pages
*/
if (zone_idx(zone) == ZONE_MOVABLE)
return true;
-
- if (get_pageblock_migratetype(page) == MIGRATE_MOVABLE)
+ mt = get_pageblock_migratetype(page);
+ if (mt == MIGRATE_MOVABLE || is_migrate_cma(mt))
return true;
pfn = page_to_pfn(page);
@@ -5561,6 +5607,193 @@
spin_unlock_irqrestore(&zone->lock, flags);
}
+#ifdef CONFIG_CMA
+
+static unsigned long pfn_max_align_down(unsigned long pfn)
+{
+ return pfn & ~(max_t(unsigned long, MAX_ORDER_NR_PAGES,
+ pageblock_nr_pages) - 1);
+}
+
+static unsigned long pfn_max_align_up(unsigned long pfn)
+{
+ return ALIGN(pfn, max_t(unsigned long, MAX_ORDER_NR_PAGES,
+ pageblock_nr_pages));
+}
+
+static struct page *
+__alloc_contig_migrate_alloc(struct page *page, unsigned long private,
+ int **resultp)
+{
+ return alloc_page(GFP_HIGHUSER_MOVABLE);
+}
+
+/* [start, end) must belong to a single zone. */
+static int __alloc_contig_migrate_range(unsigned long start, unsigned long end)
+{
+ /* This function is based on compact_zone() from compaction.c. */
+
+ unsigned long pfn = start;
+ unsigned int tries = 0;
+ int ret = 0;
+
+ struct compact_control cc = {
+ .nr_migratepages = 0,
+ .order = -1,
+ .zone = page_zone(pfn_to_page(start)),
+ .sync = true,
+ };
+ INIT_LIST_HEAD(&cc.migratepages);
+
+ migrate_prep_local();
+
+ while (pfn < end || !list_empty(&cc.migratepages)) {
+ if (fatal_signal_pending(current)) {
+ ret = -EINTR;
+ break;
+ }
+
+ if (list_empty(&cc.migratepages)) {
+ cc.nr_migratepages = 0;
+ pfn = isolate_migratepages_range(cc.zone, &cc,
+ pfn, end);
+ if (!pfn) {
+ ret = -EINTR;
+ break;
+ }
+ tries = 0;
+ } else if (++tries == 5) {
+ ret = ret < 0 ? ret : -EBUSY;
+ break;
+ }
+
+ ret = migrate_pages(&cc.migratepages,
+ __alloc_contig_migrate_alloc,
+ 0, false, true);
+ }
+
+ putback_lru_pages(&cc.migratepages);
+ return ret > 0 ? 0 : ret;
+}
+
+/**
+ * alloc_contig_range() -- tries to allocate given range of pages
+ * @start: start PFN to allocate
+ * @end: one-past-the-last PFN to allocate
+ *
+ * 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.
+ *
+ * The PFN range must belong to a single zone.
+ *
+ * Returns zero on success or negative error code. On success all
+ * 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)
+{
+ struct zone *zone = page_zone(pfn_to_page(start));
+ unsigned long outer_start, outer_end;
+ int ret = 0, order;
+
+ /*
+ * What we do here is we mark all pageblocks in range as
+ * MIGRATE_ISOLATE. Because pageblock and max order pages may
+ * have different sizes, and due to the way page allocator
+ * work, we align the range to biggest of the two pages so
+ * that page allocator won't try to merge buddies from
+ * different pageblocks and change MIGRATE_ISOLATE to some
+ * other migration type.
+ *
+ * Once the pageblocks are marked as MIGRATE_ISOLATE, we
+ * migrate the pages from an unaligned range (ie. pages that
+ * we are interested in). This will put all the pages in
+ * range back to page allocator as MIGRATE_ISOLATE.
+ *
+ * When this is done, we take the pages in range from page
+ * 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.
+ */
+
+ ret = start_isolate_page_range(pfn_max_align_down(start),
+ pfn_max_align_up(end));
+ if (ret)
+ goto done;
+
+ ret = __alloc_contig_migrate_range(start, end);
+ if (ret)
+ goto done;
+
+ /*
+ * Pages from [start, end) are within a MAX_ORDER_NR_PAGES
+ * aligned blocks that are marked as MIGRATE_ISOLATE. What's
+ * more, all pages in [start, end) are free in page allocator.
+ * What we are going to do is to allocate all pages from
+ * [start, end) (that is remove them from page allocator).
+ *
+ * The only problem is that pages at the beginning and at the
+ * end of interesting range may be not aligned with pages that
+ * page allocator holds, ie. they can be part of higher order
+ * pages. Because of this, we reserve the bigger range and
+ * once this is done free the pages we are not interested in.
+ *
+ * We don't have to hold zone->lock here because the pages are
+ * isolated thus they won't get removed from buddy.
+ */
+
+ lru_add_drain_all();
+ drain_all_pages();
+
+ order = 0;
+ outer_start = start;
+ while (!PageBuddy(pfn_to_page(outer_start))) {
+ if (++order >= MAX_ORDER) {
+ ret = -EBUSY;
+ goto done;
+ }
+ outer_start &= ~0UL << order;
+ }
+
+ /* Make sure the range is really isolated. */
+ if (test_pages_isolated(outer_start, end)) {
+ pr_warn("alloc_contig_range test_pages_isolated(%lx, %lx) failed\n",
+ outer_start, end);
+ ret = -EBUSY;
+ goto done;
+ }
+
+ outer_end = isolate_freepages_range(outer_start, end);
+ if (!outer_end) {
+ ret = -EBUSY;
+ goto done;
+ }
+
+ /* Free head and tail (if any) */
+ if (start != outer_start)
+ free_contig_range(outer_start, start - outer_start);
+ if (end != outer_end)
+ free_contig_range(end, outer_end - end);
+
+done:
+ undo_isolate_page_range(pfn_max_align_down(start),
+ pfn_max_align_up(end));
+ return ret;
+}
+
+void free_contig_range(unsigned long pfn, unsigned nr_pages)
+{
+ for (; nr_pages--; ++pfn)
+ __free_page(pfn_to_page(pfn));
+}
+#endif
+
#ifdef CONFIG_MEMORY_HOTREMOVE
/*
* All pages in the range must be isolated before calling this.
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 7db1b9b..0dad31dc 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -613,6 +613,9 @@
"Reclaimable",
"Movable",
"Reserve",
+#ifdef CONFIG_CMA
+ "CMA",
+#endif
"Isolate",
};