From db7829c6cc32f3c0c9a324118d743acb1abff081 Mon Sep 17 00:00:00 2001 From: Brian Gerst Date: Thu, 9 Sep 2010 18:17:26 +0200 Subject: x86, percpu: Optimize this_cpu_ptr Allow arches to implement __this_cpu_ptr, and provide an x86 version. Before: movq $foo, %rax movq %gs:this_cpu_off, %rdx addq %rdx, %rax After: movq $foo, %rax addq %gs:this_cpu_off, %rax The benefit is doing it in one less instruction and not clobbering a temporary register. tj: * Beefed up the comment a bit and renamed in-macro temp variable to match neighboring macros. * Folded fix for const pointer case found in linux-next. * Fixed sparse notation. Signed-off-by: Brian Gerst Signed-off-by: Tejun Heo --- include/asm-generic/percpu.h | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'include/asm-generic') diff --git a/include/asm-generic/percpu.h b/include/asm-generic/percpu.h index 08923b6..ec64311 100644 --- a/include/asm-generic/percpu.h +++ b/include/asm-generic/percpu.h @@ -60,9 +60,14 @@ extern unsigned long __per_cpu_offset[NR_CPUS]; #define __raw_get_cpu_var(var) \ (*SHIFT_PERCPU_PTR(&(var), __my_cpu_offset)) -#define this_cpu_ptr(ptr) SHIFT_PERCPU_PTR(ptr, my_cpu_offset) +#ifndef __this_cpu_ptr #define __this_cpu_ptr(ptr) SHIFT_PERCPU_PTR(ptr, __my_cpu_offset) - +#endif +#ifdef CONFIG_DEBUG_PREEMPT +#define this_cpu_ptr(ptr) SHIFT_PERCPU_PTR(ptr, my_cpu_offset) +#else +#define this_cpu_ptr(ptr) __this_cpu_ptr(ptr) +#endif #ifdef CONFIG_HAVE_SETUP_PER_CPU_AREA extern void setup_per_cpu_areas(void); -- cgit v1.1