1 files changed, 10 insertions, 0 deletions
diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
index 627767d6169..a65979a5f75 100644
--- a/arch/powerpc/mm/pgtable.c
+++ b/arch/powerpc/mm/pgtable.c
@@ -30,6 +30,14 @@
 #include <asm/tlbflush.h>
 #include <asm/tlb.h>
 
+#ifdef CONFIG_SMP
+
+/*
+ * Handle batching of page table freeing on SMP. Page tables are
+ * queued up and send to be freed later by RCU in order to avoid
+ * freeing a page table page that is being walked without locks
+ */
+
 static DEFINE_PER_CPU(struct pte_freelist_batch *, pte_freelist_cur);
 static unsigned long pte_freelist_forced_free;
 
@@ -116,6 +124,8 @@ void pte_free_finish(void)
 	*batchp = NULL;
 }
 
+#endif /* CONFIG_SMP */
+
 /*
  * Handle i/d cache flushing, called from set_pte_at() or ptep_set_access_flags()
  */