From f039b754714a422959027cb18bb33760eb8153f0 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Wed, 2 May 2007 19:27:12 +0200 Subject: [PATCH] x86: Don't use MWAIT on AMD Family 10 It doesn't put the CPU into deeper sleep states, so it's better to use the standard idle loop to save power. But allow to reenable it anyways for benchmarking. I also removed the obsolete idle=halt on i386 Cc: andreas.herrmann@amd.com Signed-off-by: Andi Kleen --- arch/i386/kernel/cpu/amd.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'arch/i386/kernel/cpu/amd.c') diff --git a/arch/i386/kernel/cpu/amd.c b/arch/i386/kernel/cpu/amd.c index 2d47db482972..197cda62caa3 100644 --- a/arch/i386/kernel/cpu/amd.c +++ b/arch/i386/kernel/cpu/amd.c @@ -53,6 +53,8 @@ static __cpuinit int amd_apic_timer_broken(void) return 0; } +int force_mwait __cpuinitdata; + static void __cpuinit init_amd(struct cpuinfo_x86 *c) { u32 l, h; @@ -275,6 +277,9 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c) if (amd_apic_timer_broken()) set_bit(X86_FEATURE_LAPIC_TIMER_BROKEN, c->x86_capability); + + if (c->x86 == 0x10 && !force_mwait) + clear_bit(X86_FEATURE_MWAIT, c->x86_capability); } static unsigned int __cpuinit amd_size_cache(struct cpuinfo_x86 * c, unsigned int size) -- cgit v1.2.3