From 0ffe984917b9cd6ecc19ffbc06f35869d8c18df8 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Tue, 28 Mar 2006 22:54:38 -0800 Subject: [PATCH] [IA64] Prefetch mmap_sem in ia64_do_page_fault() Take a hint from an x86_64 optimization by Arjan van de Ven and use it for ia64. See a9ba9a3b3897561d01e04cd21433746df46548c0 Prefetch the mmap_sem, which is critical for the performance of the page fault handler. Note: mm may be NULL but I guess that is safe. See 458f935527372499b714bf4f8e646a68bb0f52e3 Signed-off-by: Christoph Lameter Signed-off-by: Tony Luck --- arch/ia64/mm/fault.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/ia64/mm/fault.c b/arch/ia64/mm/fault.c index af7eb087dca7..d98ec49570b8 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.. */