diff --git a/ap/os/linux/linux-3.4.x/mm/compaction.c b/ap/os/linux/linux-3.4.x/mm/compaction.c
new file mode 100644
index 0000000..3c8d7fe
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/mm/compaction.c
@@ -0,0 +1,798 @@
+/*
+ * linux/mm/compaction.c
+ *
+ * Memory compaction for the reduction of external fragmentation. Note that
+ * this heavily depends upon page migration to do all the real heavy
+ * lifting
+ *
+ * Copyright IBM Corp. 2007-2010 Mel Gorman <mel@csn.ul.ie>
+ */
+#include <linux/swap.h>
+#include <linux/migrate.h>
+#include <linux/compaction.h>
+#include <linux/mm_inline.h>
+#include <linux/backing-dev.h>
+#include <linux/sysctl.h>
+#include <linux/sysfs.h>
+#include "internal.h"
+
+#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;
+	unsigned long count = 0;
+
+	list_for_each_entry_safe(page, next, freelist, lru) {
+		list_del(&page->lru);
+		__free_page(page);
+		count++;
+	}
+
+	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)
+{
+	unsigned long zone_end_pfn, end_pfn;
+	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 */
+	for (; blockpfn < end_pfn; blockpfn++, cursor++) {
+		int isolated, i;
+		struct page *page = cursor;
+
+		if (!pfn_valid_within(blockpfn))
+			continue;
+		nr_scanned++;
+
+		if (!PageBuddy(page))
+			continue;
+
+		/* Found a free page, break it into order-0 pages */
+		isolated = split_free_page(page);
+		total_isolated += isolated;
+		for (i = 0; i < isolated; i++) {
+			list_add(&page->lru, freelist);
+			page++;
+		}
+
+		/* If a page was split, advance to the end of it */
+		if (isolated) {
+			blockpfn += isolated - 1;
+			cursor += isolated - 1;
+		}
+	}
+
+	trace_mm_compaction_isolate_freepages(nr_scanned, total_isolated);
+	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.
+ */
+static void isolate_freepages(struct zone *zone,
+				struct compact_control *cc)
+{
+	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;
+
+	/*
+	 * 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);
+
+	/*
+	 * 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)) {
+			isolated = isolate_freepages_block(zone, pfn, freelist);
+			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 */
+	list_for_each_entry(page, freelist, lru) {
+		arch_alloc_page(page, 0);
+		kernel_map_pages(page, 1, 1);
+	}
+
+	cc->free_pfn = high_pfn;
+	cc->nr_freepages = nr_freepages;
+}
+
+/* Update the number of anon and file isolated pages in the zone */
+static void acct_isolated(struct zone *zone, struct compact_control *cc)
+{
+	struct page *page;
+	unsigned int count[2] = { 0, };
+
+	list_for_each_entry(page, &cc->migratepages, lru)
+		count[!!page_is_file_cache(page)]++;
+
+	__mod_zone_page_state(zone, NR_ISOLATED_ANON, count[0]);
+	__mod_zone_page_state(zone, NR_ISOLATED_FILE, count[1]);
+}
+
+/* Similar to reclaim, but different enough that they don't share logic */
+static bool too_many_isolated(struct zone *zone)
+{
+	unsigned long active, inactive, isolated;
+
+	inactive = zone_page_state(zone, NR_INACTIVE_FILE) +
+					zone_page_state(zone, NR_INACTIVE_ANON);
+	active = zone_page_state(zone, NR_ACTIVE_FILE) +
+					zone_page_state(zone, NR_ACTIVE_ANON);
+	isolated = zone_page_state(zone, NR_ISOLATED_FILE) +
+					zone_page_state(zone, NR_ISOLATED_ANON);
+
+	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.
+ */
+static isolate_migrate_t isolate_migratepages(struct zone *zone,
+					struct compact_control *cc)
+{
+	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,
+	 * delay for some time until fewer pages are isolated
+	 */
+	while (unlikely(too_many_isolated(zone))) {
+		/* async migration should just abort */
+		if (!cc->sync)
+			return ISOLATE_ABORT;
+
+		congestion_wait(BLK_RW_ASYNC, HZ/10);
+
+		if (fatal_signal_pending(current))
+			return ISOLATE_ABORT;
+	}
+
+	/* Time to isolate some pages for migration */
+	cond_resched();
+	spin_lock_irq(&zone->lru_lock);
+	for (; low_pfn < end_pfn; low_pfn++) {
+		struct page *page;
+		bool locked = true;
+
+		/* give a chance to irqs before checking need_resched() */
+		if (!((low_pfn+1) % SWAP_CLUSTER_MAX)) {
+			spin_unlock_irq(&zone->lru_lock);
+			locked = false;
+		}
+		if (need_resched() || spin_is_contended(&zone->lru_lock)) {
+			if (locked)
+				spin_unlock_irq(&zone->lru_lock);
+			cond_resched();
+			spin_lock_irq(&zone->lru_lock);
+			if (fatal_signal_pending(current))
+				break;
+		} else if (!locked)
+			spin_lock_irq(&zone->lru_lock);
+
+		/*
+		 * migrate_pfn does not necessarily start aligned to a
+		 * pageblock. Ensure that pfn_valid is called when moving
+		 * into a new MAX_ORDER_NR_PAGES range in case of large
+		 * memory holes within the zone
+		 */
+		if ((low_pfn & (MAX_ORDER_NR_PAGES - 1)) == 0) {
+			if (!pfn_valid(low_pfn)) {
+				low_pfn += MAX_ORDER_NR_PAGES - 1;
+				continue;
+			}
+		}
+
+		if (!pfn_valid_within(low_pfn))
+			continue;
+		nr_scanned++;
+
+		/*
+		 * Get the page and ensure the page is within the same zone.
+		 * See the comment in isolate_freepages about overlapping
+		 * nodes. It is deliberate that the new zone lock is not taken
+		 * as memory compaction should not move pages between nodes.
+		 */
+		page = pfn_to_page(low_pfn);
+		if (page_zone(page) != zone)
+			continue;
+
+		/* Skip if free */
+		if (PageBuddy(page))
+			continue;
+
+		/*
+		 * For async migration, also only scan in MOVABLE blocks. Async
+		 * migration is optimistic to see if the minimum amount of work
+		 * satisfies the allocation
+		 */
+		pageblock_nr = low_pfn >> pageblock_order;
+		if (!cc->sync && last_pageblock_nr != pageblock_nr &&
+				get_pageblock_migratetype(page) != MIGRATE_MOVABLE) {
+			low_pfn += pageblock_nr_pages;
+			low_pfn = ALIGN(low_pfn, pageblock_nr_pages) - 1;
+			last_pageblock_nr = pageblock_nr;
+			continue;
+		}
+
+		if (!PageLRU(page))
+			continue;
+
+		/*
+		 * PageLRU is set, and lru_lock excludes isolation,
+		 * splitting and collapsing (collapsing has already
+		 * happened if PageLRU is set).
+		 */
+		if (PageTransHuge(page)) {
+			low_pfn += (1 << compound_order(page)) - 1;
+			continue;
+		}
+
+		if (!cc->sync)
+			mode |= ISOLATE_ASYNC_MIGRATE;
+
+		/* Try isolate the page */
+		if (__isolate_lru_page(page, mode, 0) != 0)
+			continue;
+
+		VM_BUG_ON(PageTransCompound(page));
+
+		/* Successfully isolated */
+		del_page_from_lru_list(zone, page, page_lru(page));
+		list_add(&page->lru, migratelist);
+		cc->nr_migratepages++;
+		nr_isolated++;
+
+		/* Avoid isolating too much */
+		if (cc->nr_migratepages == COMPACT_CLUSTER_MAX) {
+			++low_pfn;
+			break;
+		}
+	}
+
+	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;
+}
+
+/*
+ * This is a migrate-callback that "allocates" freepages by taking pages
+ * from the isolated freelists in the block we are migrating to.
+ */
+static struct page *compaction_alloc(struct page *migratepage,
+					unsigned long data,
+					int **result)
+{
+	struct compact_control *cc = (struct compact_control *)data;
+	struct page *freepage;
+
+	/* Isolate free pages if necessary */
+	if (list_empty(&cc->freepages)) {
+		isolate_freepages(cc->zone, cc);
+
+		if (list_empty(&cc->freepages))
+			return NULL;
+	}
+
+	freepage = list_entry(cc->freepages.next, struct page, lru);
+	list_del(&freepage->lru);
+	cc->nr_freepages--;
+
+	return freepage;
+}
+
+/*
+ * We cannot control nr_migratepages and nr_freepages fully when migration is
+ * running as migrate_pages() has no knowledge of compact_control. When
+ * migration is complete, we count the number of pages on the lists by hand.
+ */
+static void update_nr_listpages(struct compact_control *cc)
+{
+	int nr_migratepages = 0;
+	int nr_freepages = 0;
+	struct page *page;
+
+	list_for_each_entry(page, &cc->migratepages, lru)
+		nr_migratepages++;
+	list_for_each_entry(page, &cc->freepages, lru)
+		nr_freepages++;
+
+	cc->nr_migratepages = nr_migratepages;
+	cc->nr_freepages = nr_freepages;
+}
+
+static int compact_finished(struct zone *zone,
+			    struct compact_control *cc)
+{
+	unsigned int order;
+	unsigned long watermark;
+
+	if (fatal_signal_pending(current))
+		return COMPACT_PARTIAL;
+
+	/* Compaction run completes if the migrate and free scanner meet */
+	if (cc->free_pfn <= cc->migrate_pfn)
+		return COMPACT_COMPLETE;
+
+	/*
+	 * order == -1 is expected when compacting via
+	 * /proc/sys/vm/compact_memory
+	 */
+	if (cc->order == -1)
+		return COMPACT_CONTINUE;
+
+	/* Compaction run is not finished if the watermark is not met */
+	watermark = low_wmark_pages(zone);
+	watermark += (1 << cc->order);
+
+	if (!zone_watermark_ok(zone, cc->order, watermark, 0, 0))
+		return COMPACT_CONTINUE;
+
+	/* Direct compactor: Is a suitable page free? */
+	for (order = cc->order; order < MAX_ORDER; order++) {
+		/* Job done if page is free of the right migratetype */
+		if (!list_empty(&zone->free_area[order].free_list[cc->migratetype]))
+			return COMPACT_PARTIAL;
+
+		/* Job done if allocation would set block type */
+		if (order >= pageblock_order && zone->free_area[order].nr_free)
+			return COMPACT_PARTIAL;
+	}
+
+	return COMPACT_CONTINUE;
+}
+
+/*
+ * compaction_suitable: Is this suitable to run compaction on this zone now?
+ * Returns
+ *   COMPACT_SKIPPED  - If there are too few free pages for compaction
+ *   COMPACT_PARTIAL  - If the allocation would succeed without compaction
+ *   COMPACT_CONTINUE - If compaction should run now
+ */
+unsigned long compaction_suitable(struct zone *zone, int order)
+{
+	int fragindex;
+	unsigned long watermark;
+
+	/*
+	 * order == -1 is expected when compacting via
+	 * /proc/sys/vm/compact_memory
+	 */
+	if (order == -1)
+		return COMPACT_CONTINUE;
+
+	/*
+	 * Watermarks for order-0 must be met for compaction. Note the 2UL.
+	 * This is because during migration, copies of pages need to be
+	 * allocated and for a short time, the footprint is higher
+	 */
+	watermark = low_wmark_pages(zone) + (2UL << order);
+	if (!zone_watermark_ok(zone, 0, watermark, 0, 0))
+		return COMPACT_SKIPPED;
+
+	/*
+	 * fragmentation index determines if allocation failures are due to
+	 * low memory or external fragmentation
+	 *
+	 * index of -1000 implies allocations might succeed depending on
+	 * watermarks
+	 * index towards 0 implies failure is due to lack of memory
+	 * index towards 1000 implies failure is due to fragmentation
+	 *
+	 * Only compact if a failure would be due to fragmentation.
+	 */
+	fragindex = fragmentation_index(zone, order);
+	if (fragindex >= 0 && fragindex <= sysctl_extfrag_threshold)
+		return COMPACT_SKIPPED;
+
+	if (fragindex == -1000 && zone_watermark_ok(zone, order, watermark,
+	    0, 0))
+		return COMPACT_PARTIAL;
+
+	return COMPACT_CONTINUE;
+}
+
+static int compact_zone(struct zone *zone, struct compact_control *cc)
+{
+	int ret;
+
+	ret = compaction_suitable(zone, cc->order);
+	switch (ret) {
+	case COMPACT_PARTIAL:
+	case COMPACT_SKIPPED:
+		/* Compaction is likely to fail */
+		return ret;
+	case COMPACT_CONTINUE:
+		/* Fall through to compaction */
+		;
+	}
+
+	/* Setup to move all movable pages to the end of the zone */
+	cc->migrate_pfn = zone->zone_start_pfn;
+	cc->free_pfn = cc->migrate_pfn + zone->spanned_pages;
+	cc->free_pfn &= ~(pageblock_nr_pages-1);
+
+	migrate_prep_local();
+
+	while ((ret = compact_finished(zone, cc)) == COMPACT_CONTINUE) {
+		unsigned long nr_migrate, nr_remaining;
+		int err;
+
+		switch (isolate_migratepages(zone, cc)) {
+		case ISOLATE_ABORT:
+			ret = COMPACT_PARTIAL;
+			goto out;
+		case ISOLATE_NONE:
+			continue;
+		case ISOLATE_SUCCESS:
+			;
+		}
+
+		nr_migrate = cc->nr_migratepages;
+		err = migrate_pages(&cc->migratepages, compaction_alloc,
+				(unsigned long)cc, false,
+				cc->sync ? MIGRATE_SYNC_LIGHT : MIGRATE_ASYNC);
+		update_nr_listpages(cc);
+		nr_remaining = cc->nr_migratepages;
+
+		count_vm_event(COMPACTBLOCKS);
+		count_vm_events(COMPACTPAGES, nr_migrate - nr_remaining);
+		if (nr_remaining)
+			count_vm_events(COMPACTPAGEFAILED, nr_remaining);
+		trace_mm_compaction_migratepages(nr_migrate - nr_remaining,
+						nr_remaining);
+
+		/* Release LRU pages not migrated */
+		if (err) {
+			putback_lru_pages(&cc->migratepages);
+			cc->nr_migratepages = 0;
+			if (err == -ENOMEM) {
+				ret = COMPACT_PARTIAL;
+				goto out;
+			}
+		}
+	}
+
+out:
+	/* Release free pages and check accounting */
+	cc->nr_freepages -= release_freepages(&cc->freepages);
+	VM_BUG_ON(cc->nr_freepages != 0);
+
+	return ret;
+}
+
+static unsigned long compact_zone_order(struct zone *zone,
+				 int order, gfp_t gfp_mask,
+				 bool sync)
+{
+	struct compact_control cc = {
+		.nr_freepages = 0,
+		.nr_migratepages = 0,
+		.order = order,
+		.migratetype = allocflags_to_migratetype(gfp_mask),
+		.zone = zone,
+		.sync = sync,
+	};
+	INIT_LIST_HEAD(&cc.freepages);
+	INIT_LIST_HEAD(&cc.migratepages);
+
+	return compact_zone(zone, &cc);
+}
+
+int sysctl_extfrag_threshold = 500;
+
+/**
+ * try_to_compact_pages - Direct compact to satisfy a high-order allocation
+ * @zonelist: The zonelist used for the current allocation
+ * @order: The order of the current allocation
+ * @gfp_mask: The GFP mask of the current allocation
+ * @nodemask: The allowed nodes to allocate from
+ * @sync: Whether migration is synchronous or not
+ *
+ * This is the main entry point for direct page compaction.
+ */
+unsigned long try_to_compact_pages(struct zonelist *zonelist,
+			int order, gfp_t gfp_mask, nodemask_t *nodemask,
+			bool sync)
+{
+	enum zone_type high_zoneidx = gfp_zone(gfp_mask);
+	int may_enter_fs = gfp_mask & __GFP_FS;
+	int may_perform_io = gfp_mask & __GFP_IO;
+	struct zoneref *z;
+	struct zone *zone;
+	int rc = COMPACT_SKIPPED;
+
+	/*
+	 * Check whether it is worth even starting compaction. The order check is
+	 * made because an assumption is made that the page allocator can satisfy
+	 * the "cheaper" orders without taking special steps
+	 */
+	if (!order || !may_enter_fs || !may_perform_io)
+		return rc;
+
+	count_vm_event(COMPACTSTALL);
+
+	/* Compact each zone in the list */
+	for_each_zone_zonelist_nodemask(zone, z, zonelist, high_zoneidx,
+								nodemask) {
+		int status;
+
+		status = compact_zone_order(zone, order, gfp_mask, sync);
+		rc = max(status, rc);
+
+		/* If a normal allocation would succeed, stop compacting */
+		if (zone_watermark_ok(zone, order, low_wmark_pages(zone), 0, 0))
+			break;
+	}
+
+	return rc;
+}
+
+
+/* Compact all zones within a node */
+static int __compact_pgdat(pg_data_t *pgdat, struct compact_control *cc)
+{
+	int zoneid;
+	struct zone *zone;
+
+	for (zoneid = 0; zoneid < MAX_NR_ZONES; zoneid++) {
+
+		zone = &pgdat->node_zones[zoneid];
+		if (!populated_zone(zone))
+			continue;
+
+		cc->nr_freepages = 0;
+		cc->nr_migratepages = 0;
+		cc->zone = zone;
+		INIT_LIST_HEAD(&cc->freepages);
+		INIT_LIST_HEAD(&cc->migratepages);
+
+		if (cc->order == -1 || !compaction_deferred(zone, cc->order))
+			compact_zone(zone, cc);
+
+		if (cc->order > 0) {
+			int ok = zone_watermark_ok(zone, cc->order,
+						low_wmark_pages(zone), 0, 0);
+			if (ok && cc->order > zone->compact_order_failed)
+				zone->compact_order_failed = cc->order + 1;
+			/* Currently async compaction is never deferred. */
+			else if (!ok && cc->sync)
+				defer_compaction(zone, cc->order);
+		}
+
+		VM_BUG_ON(!list_empty(&cc->freepages));
+		VM_BUG_ON(!list_empty(&cc->migratepages));
+	}
+
+	return 0;
+}
+
+int compact_pgdat(pg_data_t *pgdat, int order)
+{
+	struct compact_control cc = {
+		.order = order,
+		.sync = false,
+	};
+
+	return __compact_pgdat(pgdat, &cc);
+}
+
+static int compact_node(int nid)
+{
+	struct compact_control cc = {
+		.order = -1,
+		.sync = true,
+	};
+
+	return __compact_pgdat(NODE_DATA(nid), &cc);
+}
+
+/* Compact all nodes in the system */
+static void compact_nodes(void)
+{
+	int nid;
+
+	/* Flush pending updates to the LRU lists */
+	lru_add_drain_all();
+
+	for_each_online_node(nid)
+		compact_node(nid);
+}
+
+/* The written value is actually unused, all memory is compacted */
+int sysctl_compact_memory;
+
+/* This is the entry point for compacting all nodes via /proc/sys/vm */
+int sysctl_compaction_handler(struct ctl_table *table, int write,
+			void __user *buffer, size_t *length, loff_t *ppos)
+{
+	if (write)
+		compact_nodes();
+
+	return 0;
+}
+
+int sysctl_extfrag_handler(struct ctl_table *table, int write,
+			void __user *buffer, size_t *length, loff_t *ppos)
+{
+	proc_dointvec_minmax(table, write, buffer, length, ppos);
+
+	return 0;
+}
+
+#if defined(CONFIG_SYSFS) && defined(CONFIG_NUMA)
+ssize_t sysfs_compact_node(struct device *dev,
+			struct device_attribute *attr,
+			const char *buf, size_t count)
+{
+	int nid = dev->id;
+
+	if (nid >= 0 && nid < nr_node_ids && node_online(nid)) {
+		/* Flush pending updates to the LRU lists */
+		lru_add_drain_all();
+
+		compact_node(nid);
+	}
+
+	return count;
+}
+static DEVICE_ATTR(compact, S_IWUSR, NULL, sysfs_compact_node);
+
+int compaction_register_node(struct node *node)
+{
+	return device_create_file(&node->dev, &dev_attr_compact);
+}
+
+void compaction_unregister_node(struct node *node)
+{
+	return device_remove_file(&node->dev, &dev_attr_compact);
+}
+#endif /* CONFIG_SYSFS && CONFIG_NUMA */