Be more agressive about stealing when MIGRATE_RECLAIMABLE allocations fallback
MIGRATE_RECLAIMABLE allocations tend to be very bursty in nature like when
updatedb starts. It is likely this will occur in situations where MAX_ORDER
blocks of pages are not free. This means that updatedb can scatter
MIGRATE_RECLAIMABLE pages throughout the address space. This patch is more
agressive about stealing blocks of pages for MIGRATE_RECLAIMABLE.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index e1d87ee..b864584 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -821,11 +821,23 @@
/*
* If breaking a large block of pages, move all free
- * pages to the preferred allocation list
+ * pages to the preferred allocation list. If falling
+ * back for a reclaimable kernel allocation, be more
+ * agressive about taking ownership of free pages
*/
- if (unlikely(current_order >= MAX_ORDER / 2)) {
+ if (unlikely(current_order >= MAX_ORDER / 2) ||
+ start_migratetype == MIGRATE_RECLAIMABLE) {
+ unsigned long pages;
+ pages = move_freepages_block(zone, page,
+ start_migratetype);
+
+ /* Claim the whole block if over half of it is free */
+ if ((pages << current_order) >= (1 << (MAX_ORDER-2)) &&
+ migratetype != MIGRATE_HIGHATOMIC)
+ set_pageblock_migratetype(page,
+ start_migratetype);
+
migratetype = start_migratetype;
- move_freepages_block(zone, page, migratetype);
}
/* Remove the page from the freelists */