1 files changed, 15 insertions, 83 deletions

diff --git a/mm/compaction.c b/mm/compaction.c
index 6b807e466497..c62bd063d766 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -816,6 +816,7 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone,
 static int compact_finished(struct zone *zone,
                             struct compact_control *cc)
 {
+        unsigned int order;
         unsigned long watermark;
 
         if (fatal_signal_pending(current))
@@ -850,22 +851,16 @@ static int compact_finished(struct zone *zone,
                 return COMPACT_CONTINUE;
 
         /* Direct compactor: Is a suitable page free? */
-        if (cc->page) {
-                /* Was a suitable page captured? */
-                if (*cc->page)
+        for (order = cc->order; order < MAX_ORDER; order++) {
+                struct free_area *area = &zone->free_area[order];
+
+                /* Job done if page is free of the right migratetype */
+                if (!list_empty(&area->free_list[cc->migratetype]))
+                        return COMPACT_PARTIAL;
+
+                /* Job done if allocation would set block type */
+                if (cc->order >= pageblock_order && area->nr_free)
                         return COMPACT_PARTIAL;
-        } else {
-                unsigned int order;
-                for (order = cc->order; order < MAX_ORDER; order++) {
-                        struct free_area *area = &zone->free_area[cc->order];
-                        /* Job done if page is free of the right migratetype */
-                        if (!list_empty(&area->free_list[cc->migratetype]))
-                                return COMPACT_PARTIAL;
-
-                        /* Job done if allocation would set block type */
-                        if (cc->order >= pageblock_order && area->nr_free)
-                                return COMPACT_PARTIAL;
-                }
         }
 
         return COMPACT_CONTINUE;
@@ -921,60 +916,6 @@ unsigned long compaction_suitable(struct zone *zone, int order)
         return COMPACT_CONTINUE;
 }
 
-static void compact_capture_page(struct compact_control *cc)
-{
-        unsigned long flags;
-        int mtype, mtype_low, mtype_high;
-
-        if (!cc->page || *cc->page)
-                return;
-
-        /*
-         * For MIGRATE_MOVABLE allocations we capture a suitable page ASAP
-         * regardless of the migratetype of the freelist is is captured from.
-         * This is fine because the order for a high-order MIGRATE_MOVABLE
-         * allocation is typically at least a pageblock size and overall
-         * fragmentation is not impaired. Other allocation types must
-         * capture pages from their own migratelist because otherwise they
-         * could pollute other pageblocks like MIGRATE_MOVABLE with
-         * difficult to move pages and making fragmentation worse overall.
-         */
-        if (cc->migratetype == MIGRATE_MOVABLE) {
-                mtype_low = 0;
-                mtype_high = MIGRATE_PCPTYPES;
-        } else {
-                mtype_low = cc->migratetype;
-                mtype_high = cc->migratetype + 1;
-        }
-
-        /* Speculatively examine the free lists without zone lock */
-        for (mtype = mtype_low; mtype < mtype_high; mtype++) {
-                int order;
-                for (order = cc->order; order < MAX_ORDER; order++) {
-                        struct page *page;
-                        struct free_area *area;
-                        area = &(cc->zone->free_area[order]);
-                        if (list_empty(&area->free_list[mtype]))
-                                continue;
-
-                        /* Take the lock and attempt capture of the page */
-                        if (!compact_trylock_irqsave(&cc->zone->lock, &flags, cc))
-                                return;
-                        if (!list_empty(&area->free_list[mtype])) {
-                                page = list_entry(area->free_list[mtype].next,
-                                                        struct page, lru);
-                                if (capture_free_page(page, cc->order, mtype)) {
-                                        spin_unlock_irqrestore(&cc->zone->lock,
-                                                                        flags);
-                                        *cc->page = page;
-                                        return;
-                                }
-                        }
-                        spin_unlock_irqrestore(&cc->zone->lock, flags);
-                }
-        }
-}
-
 static int compact_zone(struct zone *zone, struct compact_control *cc)
 {
         int ret;
@@ -1054,9 +995,6 @@ static int compact_zone(struct zone *zone, struct compact_control *cc)
                                 goto out;
                         }
                 }
-
-                /* Capture a page now if it is a suitable size */
-                compact_capture_page(cc);
         }
 
 out:
@@ -1069,8 +1007,7 @@ out:
 
 static unsigned long compact_zone_order(struct zone *zone,
                                  int order, gfp_t gfp_mask,
-                                 bool sync, bool *contended,
-                                 struct page **page)
+                                 bool sync, bool *contended)
 {
         unsigned long ret;
         struct compact_control cc = {
@@ -1080,7 +1017,6 @@ static unsigned long compact_zone_order(struct zone *zone,
                 .migratetype = allocflags_to_migratetype(gfp_mask),
                 .zone = zone,
                 .sync = sync,
-                .page = page,
         };
         INIT_LIST_HEAD(&cc.freepages);
         INIT_LIST_HEAD(&cc.migratepages);
@@ -1110,7 +1046,7 @@ int sysctl_extfrag_threshold = 500;
  */
 unsigned long try_to_compact_pages(struct zonelist *zonelist,
                         int order, gfp_t gfp_mask, nodemask_t *nodemask,
-                        bool sync, bool *contended, struct page **page)
+                        bool sync, bool *contended)
 {
         enum zone_type high_zoneidx = gfp_zone(gfp_mask);
         int may_enter_fs = gfp_mask & __GFP_FS;
@@ -1136,7 +1072,7 @@ unsigned long try_to_compact_pages(struct zonelist *zonelist,
                 int status;
 
                 status = compact_zone_order(zone, order, gfp_mask, sync,
-                                                contended, page);
+                                                contended);
                 rc = max(status, rc);
 
                 /* If a normal allocation would succeed, stop compacting */
@@ -1192,7 +1128,6 @@ int compact_pgdat(pg_data_t *pgdat, int order)
         struct compact_control cc = {
                 .order = order,
                 .sync = false,
-                .page = NULL,
         };
 
         return __compact_pgdat(pgdat, &cc);
@@ -1203,14 +1138,13 @@ static int compact_node(int nid)
         struct compact_control cc = {
                 .order = -1,
                 .sync = true,
-                .page = NULL,
         };
 
         return __compact_pgdat(NODE_DATA(nid), &cc);
 }
 
 /* Compact all nodes in the system */
-static int compact_nodes(void)
+static void compact_nodes(void)
 {
         int nid;
 
@@ -1219,8 +1153,6 @@ static int compact_nodes(void)
 
         for_each_online_node(nid)
                 compact_node(nid);
-
-        return COMPACT_COMPLETE;
 }
 
 /* The written value is actually unused, all memory is compacted */
@@ -1231,7 +1163,7 @@ int sysctl_compaction_handler(struct ctl_table *table, int write,
                         void __user *buffer, size_t *length, loff_t *ppos)
 {
         if (write)
-                return compact_nodes();
+                compact_nodes();
 
         return 0;
 }