UBUNTU: SAUCE: Import aufs driver

[mirror_ubuntu-zesty-kernel.git] / mm / compaction.c

diff --git a/mm/compaction.c b/mm/compaction.c
index 223464227299557d2f3139f26fa08abcd04cc532..949198d012602002ca75fd47a03845e571eca53e 100644 (file)
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -818,6 +818,13 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
                    page_count(page) > page_mapcount(page))
                        goto isolate_fail;
 
+               /*
+                * Only allow to migrate anonymous pages in GFP_NOFS context
+                * because those do not depend on fs locks.
+                */
+               if (!(cc->gfp_mask & __GFP_FS) && page_mapping(page))
+                       goto isolate_fail;
+
                /* If we already hold the lock, we can skip some rechecking */
                if (!locked) {
                        locked = compact_trylock_irqsave(zone_lru_lock(zone),
@@ -1677,14 +1684,16 @@ enum compact_result try_to_compact_pages(gfp_t gfp_mask, unsigned int order,
                unsigned int alloc_flags, const struct alloc_context *ac,
                enum compact_priority prio)
 {
-       int may_enter_fs = gfp_mask & __GFP_FS;
        int may_perform_io = gfp_mask & __GFP_IO;
        struct zoneref *z;
        struct zone *zone;
        enum compact_result rc = COMPACT_SKIPPED;
 
-       /* Check if the GFP flags allow compaction */
-       if (!may_enter_fs || !may_perform_io)
+       /*
+        * Check if the GFP flags allow compaction - GFP_NOIO is really
+        * tricky context because the migration might require IO
+        */
+       if (!may_perform_io)
                return COMPACT_SKIPPED;
 
        trace_mm_compaction_try_to_compact_pages(order, gfp_mask, prio);
@@ -1751,6 +1760,7 @@ static void compact_node(int nid)
                .mode = MIGRATE_SYNC,
                .ignore_skip_hint = true,
                .whole_zone = true,
+               .gfp_mask = GFP_KERNEL,
        };
 
 
@@ -1876,6 +1886,7 @@ static void kcompactd_do_work(pg_data_t *pgdat)
                .classzone_idx = pgdat->kcompactd_classzone_idx,
                .mode = MIGRATE_SYNC_LIGHT,
                .ignore_skip_hint = true,
+               .gfp_mask = GFP_KERNEL,
 
        };
        trace_mm_compaction_kcompactd_wake(pgdat->node_id, cc.order,