From da5e09a1b3e5a9fc0b15a3feb64e921ccc55ba74 Mon Sep 17 00:00:00 2001 From: Zhao Yakui Date: Tue, 24 Jun 2008 18:01:09 +0800 Subject: ACPI : Create "idle=nomwait" bootparam "idle=nomwait" disables the use of the MWAIT instruction from both C1 (C1_FFH) and deeper (C2C3_FFH) C-states. When MWAIT is unavailable, the BIOS and OS generally negotiate to use the HALT instruction for C1, and use IO accesses for deeper C-states. This option is useful for power and performance comparisons, and also to work around BIOS bugs where broken MWAIT support is advertised. http://bugzilla.kernel.org/show_bug.cgi?id=10807 http://bugzilla.kernel.org/show_bug.cgi?id=10914 Signed-off-by: Zhao Yakui Signed-off-by: Li Shaohua Signed-off-by: Len Brown Signed-off-by: Andi Kleen --- include/asm-ia64/processor.h | 1 + include/asm-x86/processor.h | 1 + 2 files changed, 2 insertions(+) (limited to 'include') diff --git a/include/asm-ia64/processor.h b/include/asm-ia64/processor.h index f36e28a5f61e..f88fa054d01d 100644 --- a/include/asm-ia64/processor.h +++ b/include/asm-ia64/processor.h @@ -764,6 +764,7 @@ prefetchw (const void *x) extern unsigned long boot_option_idle_override; extern unsigned long idle_halt; +extern unsigned long idle_nomwait; #endif /* !__ASSEMBLY__ */ diff --git a/include/asm-x86/processor.h b/include/asm-x86/processor.h index bc221623248e..55402d2ab938 100644 --- a/include/asm-x86/processor.h +++ b/include/asm-x86/processor.h @@ -728,6 +728,7 @@ extern void select_idle_routine(const struct cpuinfo_x86 *c); extern unsigned long boot_option_idle_override; extern unsigned long idle_halt; +extern unsigned long idle_nomwait; extern void enable_sep_cpu(void); extern int sysenter_setup(void); -- cgit v1.2.3