diff --git a/[refs] b/[refs]
index 79114af6c987..61bb9271443a 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: a4936044001694f033fe4ea94d6034d51a6b465c
+refs/heads/master: b7c84c6ada2be942eca6722edb2cfaad412cd5de
diff --git a/trunk/mm/page_alloc.c b/trunk/mm/page_alloc.c
index 206920796f5f..559336de9687 100644
--- a/trunk/mm/page_alloc.c
+++ b/trunk/mm/page_alloc.c
@@ -1742,10 +1742,17 @@ inline void setup_pageset(struct per_cpu_pageset *p, unsigned long batch)
  * with interrupts disabled.
  *
  * Some NUMA counter updates may also be caught by the boot pagesets.
- * These will be discarded when bootup is complete.
+ *
+ * The boot_pagesets must be kept even after bootup is complete for
+ * unused processors and/or zones. They do play a role for bootstrapping
+ * hotplugged processors.
+ *
+ * zoneinfo_show() and maybe other functions do
+ * not check if the processor is online before following the pageset pointer.
+ * Other parts of the kernel may not check if the zone is available.
  */
 static struct per_cpu_pageset
-	boot_pageset[NR_CPUS] __initdata;
+	boot_pageset[NR_CPUS];
 
 /*
  * Dynamically allocate memory for the