> Might as well change is_debug_stack() to use __this_cpu_read() instead > of __get_cpu_var().
Subject: x86: use this_cpu for debug_stack_usage Reduces overhead a bit and frees up a couple of registers. Signed-off-by: Christoph Lameter <[email protected]> Index: linux/arch/x86/include/asm/debugreg.h =================================================================== --- linux.orig/arch/x86/include/asm/debugreg.h 2013-08-06 13:52:23.740092873 -0500 +++ linux/arch/x86/include/asm/debugreg.h 2013-08-06 13:52:23.740092873 -0500 @@ -97,11 +97,11 @@ extern void hw_breakpoint_restore(void); DECLARE_PER_CPU(int, debug_stack_usage); static inline void debug_stack_usage_inc(void) { - __get_cpu_var(debug_stack_usage)++; + __this_cpu_inc(debug_stack_usage); } static inline void debug_stack_usage_dec(void) { - __get_cpu_var(debug_stack_usage)--; + __this_cpu_dec(debug_stack_usage); } int is_debug_stack(unsigned long addr); void debug_stack_set_zero(void); Index: linux/arch/x86/kernel/cpu/common.c =================================================================== --- linux.orig/arch/x86/kernel/cpu/common.c 2013-07-19 09:06:36.850047837 -0500 +++ linux/arch/x86/kernel/cpu/common.c 2013-08-06 13:54:36.426384889 -0500 @@ -1144,9 +1144,9 @@ DEFINE_PER_CPU(int, debug_stack_usage); int is_debug_stack(unsigned long addr) { - return __get_cpu_var(debug_stack_usage) || - (addr <= __get_cpu_var(debug_stack_addr) && - addr > (__get_cpu_var(debug_stack_addr) - DEBUG_STKSZ)); + return __this_cpu_read(debug_stack_usage) || + (addr <= __this_cpu_read(debug_stack_addr) && + addr > (__this_cpu_read(debug_stack_addr) - DEBUG_STKSZ)); } DEFINE_PER_CPU(u32, debug_idt_ctr); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
