Merge "mm, page_owner: don't grab zone->lock for init_pages_in_zone()"
diff --git a/mm/page_owner.c b/mm/page_owner.c
index fe850b9..c4381d93 100644
--- a/mm/page_owner.c
+++ b/mm/page_owner.c
@@ -554,11 +554,17 @@
continue;
/*
- * We are safe to check buddy flag and order, because
- * this is init stage and only single thread runs.
+ * To avoid having to grab zone->lock, be a little
+ * careful when reading buddy page order. The only
+ * danger is that we skip too much and potentially miss
+ * some early allocated pages, which is better than
+ * heavy lock contention.
*/
if (PageBuddy(page)) {
- pfn += (1UL << page_order(page)) - 1;
+ unsigned long order = page_order_unsafe(page);
+
+ if (order > 0 && order < MAX_ORDER)
+ pfn += (1UL << order) - 1;
continue;
}
@@ -577,6 +583,7 @@
set_page_owner(page, 0, 0);
count++;
}
+ cond_resched();
}
pr_info("Node %d, zone %8s: page owner found early allocated %lu pages\n",
@@ -587,15 +594,12 @@
{
struct zone *zone;
struct zone *node_zones = pgdat->node_zones;
- unsigned long flags;
for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
if (!populated_zone(zone))
continue;
- spin_lock_irqsave(&zone->lock, flags);
init_pages_in_zone(pgdat, zone);
- spin_unlock_irqrestore(&zone->lock, flags);
}
}