X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=blobdiff_plain;f=mm%2Fmemory_hotplug.c;h=19389cdc16a502f04726f4e12bab64cb8e4e1879;hb=fe8b7085cac3b0db03cdbb26d9309bc27325df0a;hp=0a54ffac8c682ae5c940642c6b5d45cfb22cada5;hpb=90568ecf561540fa330511e21fcd823b0c3829c6;p=linux.git

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 0a54ffac8c68..19389cdc16a5 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -574,7 +574,13 @@ EXPORT_SYMBOL_GPL(restore_online_page_callback);
 
 void generic_online_page(struct page *page, unsigned int order)
 {
-	kernel_map_pages(page, 1 << order, 1);
+	/*
+	 * Freeing the page with debug_pagealloc enabled will try to unmap it,
+	 * so we should map it first. This is better than introducing a special
+	 * case in page freeing fast path.
+	 */
+	if (debug_pagealloc_enabled_static())
+		kernel_map_pages(page, 1 << order, 1);
 	__free_pages_core(page, order);
 	totalram_pages_add(1UL << order);
 #ifdef CONFIG_HIGHMEM