From 909ea96468096b07fbb41aaf69be060d92bd9271 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Wed, 8 Dec 2010 16:22:55 +0100 Subject: core: Replace __get_cpu_var with __this_cpu_read if not used for an address. __get_cpu_var() can be replaced with this_cpu_read and will then use a single read instruction with implied address calculation to access the correct per cpu instance. However, the address of a per cpu variable passed to __this_cpu_read() cannot be determined (since it's an implied address conversion through segment prefixes). Therefore apply this only to uses of __get_cpu_var where the address of the variable is not used. Cc: Pekka Enberg Cc: Hugh Dickins Cc: Thomas Gleixner Acked-by: H. Peter Anvin Signed-off-by: Christoph Lameter Signed-off-by: Tejun Heo --- include/asm-generic/irq_regs.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'include/asm-generic') diff --git a/include/asm-generic/irq_regs.h b/include/asm-generic/irq_regs.h index 5ae1d07d4a12..6bf9355fa7eb 100644 --- a/include/asm-generic/irq_regs.h +++ b/include/asm-generic/irq_regs.h @@ -22,15 +22,15 @@ DECLARE_PER_CPU(struct pt_regs *, __irq_regs); static inline struct pt_regs *get_irq_regs(void) { - return __get_cpu_var(__irq_regs); + return __this_cpu_read(__irq_regs); } static inline struct pt_regs *set_irq_regs(struct pt_regs *new_regs) { - struct pt_regs *old_regs, **pp_regs = &__get_cpu_var(__irq_regs); + struct pt_regs *old_regs; - old_regs = *pp_regs; - *pp_regs = new_regs; + old_regs = __this_cpu_read(__irq_regs); + __this_cpu_write(__irq_regs, new_regs); return old_regs; } -- cgit v1.2.3