summaryrefslogtreecommitdiff
path: root/mm/page_alloc.c
diff options
context:
space:
mode:
Diffstat (limited to 'mm/page_alloc.c')
-rw-r--r--mm/page_alloc.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 7a2853b7967d..a887ba2cc91d 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1855,6 +1855,14 @@ static bool can_steal_fallback(unsigned int order, int start_mt)
if (order >= pageblock_order)
return true;
+ /*
+ * Movable pages won't cause permanent fragmentation, so when you alloc
+ * small pages, you just need to temporarily steal unmovable or
+ * reclaimable pages that are closest to the request size. After a
+ * while, memory compaction may occur to form large contiguous pages,
+ * and the next movable allocation may not need to steal. Unmovable and
+ * reclaimable allocations need to actually steal pages.
+ */
if (order >= pageblock_order / 2 ||
start_mt == MIGRATE_RECLAIMABLE ||
start_mt == MIGRATE_UNMOVABLE ||