9 files changed, 63 insertions, 34 deletions

diff --git a/include/linux/compaction.h b/include/linux/compaction.h
index 2592883d862..72cba403478 100644
--- a/include/linux/compaction.h
+++ b/include/linux/compaction.h
@@ -21,10 +21,11 @@ extern int sysctl_extfrag_handler(struct ctl_table *table, int write,
 
 extern int fragmentation_index(struct zone *zone, unsigned int order);
 extern unsigned long try_to_compact_pages(struct zonelist *zonelist,
-                        int order, gfp_t gfp_mask, nodemask_t *mask);
+                        int order, gfp_t gfp_mask, nodemask_t *mask,
+                        bool sync);
 extern unsigned long compaction_suitable(struct zone *zone, int order);
 extern unsigned long compact_zone_order(struct zone *zone, int order,
-                                                gfp_t gfp_mask);
+                                                gfp_t gfp_mask, bool sync);
 
 /* Do not skip compaction more than 64 times */
 #define COMPACT_MAX_DEFER_SHIFT 6
@@ -57,7 +58,8 @@ static inline bool compaction_deferred(struct zone *zone)
 
 #else
 static inline unsigned long try_to_compact_pages(struct zonelist *zonelist,
-                        int order, gfp_t gfp_mask, nodemask_t *nodemask)
+                        int order, gfp_t gfp_mask, nodemask_t *nodemask,
+                        bool sync)
 {
         return COMPACT_CONTINUE;
 }
@@ -68,7 +70,7 @@ static inline unsigned long compaction_suitable(struct zone *zone, int order)
 }
 
 static inline unsigned long compact_zone_order(struct zone *zone, int order,
-                                                gfp_t gfp_mask)
+                                                gfp_t gfp_mask, bool sync)
 {
         return 0;
 }
diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index 085527fb826..fa31902803f 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -13,9 +13,11 @@ extern void putback_lru_pages(struct list_head *l);
 extern int migrate_page(struct address_space *,
                         struct page *, struct page *);
 extern int migrate_pages(struct list_head *l, new_page_t x,
-                        unsigned long private, int offlining);
+                        unsigned long private, int offlining,
+                        bool sync);
 extern int migrate_huge_pages(struct list_head *l, new_page_t x,
-                        unsigned long private, int offlining);
+                        unsigned long private, int offlining,
+                        bool sync);
 
 extern int fail_migrate_page(struct address_space *,
                         struct page *, struct page *);
@@ -33,9 +35,11 @@ extern int migrate_huge_page_move_mapping(struct address_space *mapping,
 
 static inline void putback_lru_pages(struct list_head *l) {}
 static inline int migrate_pages(struct list_head *l, new_page_t x,
-                unsigned long private, int offlining) { return -ENOSYS; }
+                unsigned long private, int offlining,
+                bool sync) { return -ENOSYS; }
 static inline int migrate_huge_pages(struct list_head *l, new_page_t x,
-                unsigned long private, int offlining) { return -ENOSYS; }
+                unsigned long private, int offlining,
+                bool sync) { return -ENOSYS; }
 
 static inline int migrate_prep(void) { return -ENOSYS; }
 static inline int migrate_prep_local(void) { return -ENOSYS; }
diff --git a/mm/compaction.c b/mm/compaction.c
index 8fe917ec7c1..47fca106934 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -33,6 +33,7 @@ struct compact_control {
         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 */
 
         /* Account for isolated anon and file pages */
         unsigned long nr_anon;
@@ -455,7 +456,8 @@ static int compact_zone(struct zone *zone, struct compact_control *cc)
 
                 nr_migrate = cc->nr_migratepages;
                 migrate_pages(&cc->migratepages, compaction_alloc,
-                                                (unsigned long)cc, 0);
+                                (unsigned long)cc, 0,
+                                cc->sync);
                 update_nr_listpages(cc);
                 nr_remaining = cc->nr_migratepages;
 
@@ -482,7 +484,8 @@ static int compact_zone(struct zone *zone, struct compact_control *cc)
 }
 
 unsigned long compact_zone_order(struct zone *zone,
-                                                int order, gfp_t gfp_mask)
+                                                int order, gfp_t gfp_mask,
+                                                bool sync)
 {
         struct compact_control cc = {
                 .nr_freepages = 0,
@@ -490,6 +493,7 @@ unsigned long compact_zone_order(struct zone *zone,
                 .order = order,
                 .migratetype = allocflags_to_migratetype(gfp_mask),
                 .zone = zone,
+                .sync = sync,
         };
         INIT_LIST_HEAD(&cc.freepages);
         INIT_LIST_HEAD(&cc.migratepages);
@@ -505,11 +509,13 @@ int sysctl_extfrag_threshold = 500;
  * @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)
+                        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;
@@ -533,7 +539,7 @@ unsigned long try_to_compact_pages(struct zonelist *zonelist,
                                                                 nodemask) {
                 int status;
 
-                status = compact_zone_order(zone, order, gfp_mask);
+                status = compact_zone_order(zone, order, gfp_mask, sync);
                 rc = max(status, rc);
 
                 /* If a normal allocation would succeed, stop compacting */
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 46ab2c044b0..2323a8039a9 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1290,9 +1290,10 @@ static int soft_offline_huge_page(struct page *page, int flags)
         /* Keep page count to indicate a given hugepage is isolated. */
 
         list_add(&hpage->lru, &pagelist);
-        ret = migrate_huge_pages(&pagelist, new_page, MPOL_MF_MOVE_ALL, 0);
+        ret = migrate_huge_pages(&pagelist, new_page, MPOL_MF_MOVE_ALL, 0,
+                                true);
         if (ret) {
-                        putback_lru_pages(&pagelist);
+                putback_lru_pages(&pagelist);
                 pr_debug("soft offline: %#lx: migration failed %d, type %lx\n",
                          pfn, ret, page->flags);
                 if (ret > 0)
@@ -1413,7 +1414,8 @@ int soft_offline_page(struct page *page, int flags)
                 LIST_HEAD(pagelist);
 
                 list_add(&page->lru, &pagelist);
-                ret = migrate_pages(&pagelist, new_page, MPOL_MF_MOVE_ALL, 0);
+                ret = migrate_pages(&pagelist, new_page, MPOL_MF_MOVE_ALL,
+                                                                0, true);
                 if (ret) {
                         pr_info("soft offline: %#lx: migration failed %d, type %lx\n",
                                 pfn, ret, page->flags);
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 2c6523af547..584fc5588fd 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -733,7 +733,8 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
                         goto out;
                 }
                 /* this function returns # of failed pages */
-                ret = migrate_pages(&source, hotremove_migrate_alloc, 0, 1);
+                ret = migrate_pages(&source, hotremove_migrate_alloc, 0,
+                                                                1, true);
                 if (ret)
                         putback_lru_pages(&source);
         }
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 11ff260fb28..9db27459308 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -935,7 +935,7 @@ static int migrate_to_node(struct mm_struct *mm, int source, int dest,
                 return PTR_ERR(vma);
 
         if (!list_empty(&pagelist)) {
-                err = migrate_pages(&pagelist, new_node_page, dest, 0);
+                err = migrate_pages(&pagelist, new_node_page, dest, 0, true);
                 if (err)
                         putback_lru_pages(&pagelist);
         }
@@ -1155,7 +1155,7 @@ static long do_mbind(unsigned long start, unsigned long len,
 
                 if (!list_empty(&pagelist)) {
                         nr_failed = migrate_pages(&pagelist, new_vma_page,
-                                                (unsigned long)vma, 0);
+                                                (unsigned long)vma, 0, true);
                         if (nr_failed)
                                 putback_lru_pages(&pagelist);
                 }
diff --git a/mm/migrate.c b/mm/migrate.c
index 94875b26592..dc47f6c4035 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -614,7 +614,7 @@ static int move_to_new_page(struct page *newpage, struct page *page,
  * to the newly allocated page in newpage.
  */
 static int unmap_and_move(new_page_t get_new_page, unsigned long private,
-                        struct page *page, int force, int offlining)
+                        struct page *page, int force, int offlining, bool sync)
 {
         int rc = 0;
         int *result = NULL;
@@ -682,7 +682,7 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private,
         BUG_ON(charge);
 
         if (PageWriteback(page)) {
-                if (!force)
+                if (!force || !sync)
                         goto uncharge;
                 wait_on_page_writeback(page);
         }
@@ -827,7 +827,7 @@ move_newpage:
  */
 static int unmap_and_move_huge_page(new_page_t get_new_page,
                                 unsigned long private, struct page *hpage,
-                                int force, int offlining)
+                                int force, int offlining, bool sync)
 {
         int rc = 0;
         int *result = NULL;
@@ -841,7 +841,7 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
         rc = -EAGAIN;
 
         if (!trylock_page(hpage)) {
-                if (!force)
+                if (!force || !sync)
                         goto out;
                 lock_page(hpage);
         }
@@ -909,7 +909,8 @@ out:
  * Return: Number of pages not migrated or error code.
  */
 int migrate_pages(struct list_head *from,
-                new_page_t get_new_page, unsigned long private, int offlining)
+                new_page_t get_new_page, unsigned long private, int offlining,
+                bool sync)
 {
         int retry = 1;
         int nr_failed = 0;
@@ -929,7 +930,8 @@ int migrate_pages(struct list_head *from,
                         cond_resched();
 
                         rc = unmap_and_move(get_new_page, private,
-                                                page, pass > 2, offlining);
+                                                page, pass > 2, offlining,
+                                                sync);
 
                         switch(rc) {
                         case -ENOMEM:
@@ -958,7 +960,8 @@ out:
 }
 
 int migrate_huge_pages(struct list_head *from,
-                new_page_t get_new_page, unsigned long private, int offlining)
+                new_page_t get_new_page, unsigned long private, int offlining,
+                bool sync)
 {
         int retry = 1;
         int nr_failed = 0;
@@ -974,7 +977,8 @@ int migrate_huge_pages(struct list_head *from,
                         cond_resched();
 
                         rc = unmap_and_move_huge_page(get_new_page,
-                                        private, page, pass > 2, offlining);
+                                        private, page, pass > 2, offlining,
+                                        sync);
 
                         switch(rc) {
                         case -ENOMEM:
@@ -1107,7 +1111,7 @@ set_status:
         err = 0;
         if (!list_empty(&pagelist)) {
                 err = migrate_pages(&pagelist, new_page_node,
-                                (unsigned long)pm, 0);
+                                (unsigned long)pm, 0, true);
                 if (err)
                         putback_lru_pages(&pagelist);
         }
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 03a66a31bfc..0fd486467b4 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1812,7 +1812,8 @@ static struct page *
 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
         struct zonelist *zonelist, enum zone_type high_zoneidx,
         nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
-        int migratetype, unsigned long *did_some_progress)
+        int migratetype, unsigned long *did_some_progress,
+        bool sync_migration)
 {
         struct page *page;
         struct task_struct *tsk = current;
@@ -1822,7 +1823,7 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
 
         tsk->flags |= PF_MEMALLOC;
         *did_some_progress = try_to_compact_pages(zonelist, order, gfp_mask,
-                                                                nodemask);
+                                                nodemask, sync_migration);
         tsk->flags &= ~PF_MEMALLOC;
         if (*did_some_progress != COMPACT_SKIPPED) {
 
@@ -1859,7 +1860,8 @@ static inline struct page *
 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
         struct zonelist *zonelist, enum zone_type high_zoneidx,
         nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
-        int migratetype, unsigned long *did_some_progress)
+        int migratetype, unsigned long *did_some_progress,
+        bool sync_migration)
 {
         return NULL;
 }
@@ -2001,6 +2003,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
         unsigned long pages_reclaimed = 0;
         unsigned long did_some_progress;
         struct task_struct *p = current;
+        bool sync_migration = false;
 
         /*
          * In the slowpath, we sanity check order to avoid ever trying to
@@ -2063,14 +2066,19 @@ rebalance:
         if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
                 goto nopage;
 
-        /* Try direct compaction */
+        /*
+         * Try direct compaction. The first pass is asynchronous. Subsequent
+         * attempts after direct reclaim are synchronous
+         */
         page = __alloc_pages_direct_compact(gfp_mask, order,
                                         zonelist, high_zoneidx,
                                         nodemask,
                                         alloc_flags, preferred_zone,
-                                        migratetype, &did_some_progress);
+                                        migratetype, &did_some_progress,
+                                        sync_migration);
         if (page)
                 goto got_pg;
+        sync_migration = true;
 
         /* Try direct reclaim and then allocating */
         page = __alloc_pages_direct_reclaim(gfp_mask, order,
@@ -2134,7 +2142,8 @@ rebalance:
                                         zonelist, high_zoneidx,
                                         nodemask,
                                         alloc_flags, preferred_zone,
-                                        migratetype, &did_some_progress);
+                                        migratetype, &did_some_progress,
+                                        sync_migration);
                 if (page)
                         goto got_pg;
         }
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 10ebd74a423..8320d115c85 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2377,7 +2377,8 @@ loop_again:
                          * would ordinarily call try_to_compact_pages()
                          */
                         if (sc.order > PAGE_ALLOC_COSTLY_ORDER)
-                                compact_zone_order(zone, sc.order, sc.gfp_mask);
+                                compact_zone_order(zone, sc.order, sc.gfp_mask,
+                                                        false);
 
                         if (!zone_watermark_ok_safe(zone, order,
                                         high_wmark_pages(zone), end_zone, 0)) {