diff --git a/arch/ia64/mm/fault.c b/arch/ia64/mm/fault.c
index af7eb087dca7af7df598e8c81c475e9b365f042c..d98ec49570b80f6e9d70a66d98e070ef19cc3dba 100644
--- a/arch/ia64/mm/fault.c
+++ b/arch/ia64/mm/fault.c
@@ -60,6 +60,9 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re
 	struct siginfo si;
 	unsigned long mask;
 
+	/* mmap_sem is performance critical.... */
+	prefetchw(&mm->mmap_sem);
+
 	/*
 	 * If we're in an interrupt or have no user context, we must not take the fault..
 	 */