[PATCH] Optimize PDA accesses slightly

[safe/jmp/linux-2.6] / arch / x86_64 / kernel / setup64.c

diff --git a/arch/x86_64/kernel/setup64.c b/arch/x86_64/kernel/setup64.c
index e85cfbb..4913617 100644 (file)
--- a/arch/x86_64/kernel/setup64.c
+++ b/arch/x86_64/kernel/setup64.c
@@ -121,7 +121,10 @@ void pda_init(int cpu)
 
        /* Setup up data that may be needed in __get_free_pages early */
        asm volatile("movl %0,%%fs ; movl %0,%%gs" :: "r" (0)); 
+       /* Memory clobbers used to order PDA accessed */
+       mb();
        wrmsrl(MSR_GS_BASE, pda);
+       mb();
 
        pda->cpunumber = cpu; 
        pda->irqcount = -1;