mm: initialize hotplugged pages as reserved

Commit 92923ca ("mm: meminit: only set page reserved in the memblock region") broke memory hotplug which expects the memmap for newly added sections to be reserved until onlined by online_pages_range(). This patch marks hotplugged pages as reserved when adding new zones. Signed-off-by: Mel Gorman <[email protected]> Reported-by: David Vrabel <[email protected]> Tested-by: David Vrabel <[email protected]> Cc: Nathan Zimmer <[email protected]> Cc: Robin Holt <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
kyagi · Aug 7, 2015 · e298ff7 · e298ff7
1 parent 32e5a2a
commit e298ff7
Showing 1 changed file with 9 additions and 1 deletion.
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
@@ -446,7 +446,7 @@ static int __meminit __add_zone(struct zone *zone, unsigned long phys_start_pfn)
 	int nr_pages = PAGES_PER_SECTION;
 	int nid = pgdat->node_id;
 	int zone_type;
-	unsigned long flags;
+	unsigned long flags, pfn;
 	int ret;
 
 	zone_type = zone - pgdat->node_zones;
@@ -461,6 +461,14 @@ static int __meminit __add_zone(struct zone *zone, unsigned long phys_start_pfn)
 	pgdat_resize_unlock(zone->zone_pgdat, &flags);
 	memmap_init_zone(nr_pages, nid, zone_type,
 			 phys_start_pfn, MEMMAP_HOTPLUG);
+
+	/* online_page_range is called later and expects pages reserved */
+	for (pfn = phys_start_pfn; pfn < phys_start_pfn + nr_pages; pfn++) {
+		if (!pfn_valid(pfn))
+			continue;
+
+		SetPageReserved(pfn_to_page(pfn));
+	}
 	return 0;
 }