mm, compaction: make whole_zone flag ignore cached scanner positions

[cascardo/linux.git] / mm / compaction.c

diff --git a/mm/compaction.c b/mm/compaction.c
index 9affb29..c684ca1 100644 (file)
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1492,23 +1492,29 @@ static enum compact_result compact_zone(struct zone *zone, struct compact_contro
 
        /*
         * Setup to move all movable pages to the end of the zone. Used cached
-        * information on where the scanners should start but check that it
-        * is initialised by ensuring the values are within zone boundaries.
+        * information on where the scanners should start (unless we explicitly
+        * want to compact the whole zone), but check that it is initialised
+        * by ensuring the values are within zone boundaries.
         */
-       cc->migrate_pfn = zone->compact_cached_migrate_pfn[sync];
-       cc->free_pfn = zone->compact_cached_free_pfn;
-       if (cc->free_pfn < start_pfn || cc->free_pfn >= end_pfn) {
-               cc->free_pfn = pageblock_start_pfn(end_pfn - 1);
-               zone->compact_cached_free_pfn = cc->free_pfn;
-       }
-       if (cc->migrate_pfn < start_pfn || cc->migrate_pfn >= end_pfn) {
+       if (cc->whole_zone) {
                cc->migrate_pfn = start_pfn;
-               zone->compact_cached_migrate_pfn[0] = cc->migrate_pfn;
-               zone->compact_cached_migrate_pfn[1] = cc->migrate_pfn;
-       }
+               cc->free_pfn = pageblock_start_pfn(end_pfn - 1);
+       } else {
+               cc->migrate_pfn = zone->compact_cached_migrate_pfn[sync];
+               cc->free_pfn = zone->compact_cached_free_pfn;
+               if (cc->free_pfn < start_pfn || cc->free_pfn >= end_pfn) {
+                       cc->free_pfn = pageblock_start_pfn(end_pfn - 1);
+                       zone->compact_cached_free_pfn = cc->free_pfn;
+               }
+               if (cc->migrate_pfn < start_pfn || cc->migrate_pfn >= end_pfn) {
+                       cc->migrate_pfn = start_pfn;
+                       zone->compact_cached_migrate_pfn[0] = cc->migrate_pfn;
+                       zone->compact_cached_migrate_pfn[1] = cc->migrate_pfn;
+               }
 
-       if (cc->migrate_pfn == start_pfn)
-               cc->whole_zone = true;
+               if (cc->migrate_pfn == start_pfn)
+                       cc->whole_zone = true;
+       }
 
        cc->last_migrated_pfn = 0;
 
@@ -1747,14 +1753,6 @@ static void __compact_pgdat(pg_data_t *pgdat, struct compact_control *cc)
                INIT_LIST_HEAD(&cc->freepages);
                INIT_LIST_HEAD(&cc->migratepages);
 
-               /*
-                * When called via /proc/sys/vm/compact_memory
-                * this makes sure we compact the whole zone regardless of
-                * cached scanner positions.
-                */
-               if (is_via_compact_memory(cc->order))
-                       __reset_isolation_suitable(zone);
-
                if (is_via_compact_memory(cc->order) ||
                                !compaction_deferred(zone, cc->order))
                        compact_zone(zone, cc);
@@ -1790,6 +1788,7 @@ static void compact_node(int nid)
                .order = -1,
                .mode = MIGRATE_SYNC,
                .ignore_skip_hint = true,
+               .whole_zone = true,
        };
 
        __compact_pgdat(NODE_DATA(nid), &cc);