x86: udelay: Use this_cpu_read to avoid address calculation

The code will use a segment prefix instead of doing the lookup and
calculation.

Signed-off-by: Christoph Lameter <cl@linux.com>
Acked-by: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

diff --git a/arch/x86/lib/delay.c b/arch/x86/lib/delay.c
index ff485d3..fc45ba8 100644 (file)
--- a/arch/x86/lib/delay.c
+++ b/arch/x86/lib/delay.c
@@ -121,7 +121,7 @@ inline void __const_udelay(unsigned long xloops)
        asm("mull %%edx"
                :"=d" (xloops), "=&a" (d0)
                :"1" (xloops), "0"
-               (cpu_data(raw_smp_processor_id()).loops_per_jiffy * (HZ/4)));
+               (this_cpu_read(cpu_info.loops_per_jiffy) * (HZ/4)));
 
        __delay(++xloops);
 }