diff --git a/[refs] b/[refs]
index c23dc38167b5..74bb6870c24d 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 161ec53c702ce9df2f439804dfb9331807066daa
+refs/heads/master: 509731336313b3799cf03071d72c64fa6383895e
diff --git a/trunk/arch/x86/kernel/alternative.c b/trunk/arch/x86/kernel/alternative.c
index 4a234677e213..f4fe15ddcf94 100644
--- a/trunk/arch/x86/kernel/alternative.c
+++ b/trunk/arch/x86/kernel/alternative.c
@@ -210,6 +210,15 @@ void __init_or_module apply_alternatives(struct alt_instr *start,
 	u8 insnbuf[MAX_PATCH_LEN];
 
 	DPRINTK("%s: alt table %p -> %p\n", __func__, start, end);
+	/*
+	 * The scan order should be from start to end. A later scanned
+	 * alternative code can overwrite a previous scanned alternative code.
+	 * Some kernel functions (e.g. memcpy, memset, etc) use this order to
+	 * patch code.
+	 *
+	 * So be careful if you want to change the scan order to any other
+	 * order.
+	 */
 	for (a = start; a < end; a++) {
 		u8 *instr = a->instr;
 		BUG_ON(a->replacementlen > a->instrlen);