From 2b107d93635616db0c3f893c8cc2e6d5cd8d77b2 Mon Sep 17 00:00:00 2001 From: Jacob Pan Date: Fri, 7 May 2010 14:59:45 -0700 Subject: [PATCH] x86: Avoid check hlt for newer cpus Check hlt instruction was targeted for some older CPUs. It is an expensive operation in that it takes 4 ticks to break out the check. We can avoid such check completely for newer x86 cpus (family >= 5). [ hpa: corrected family > 5 to family >= 5 ] Signed-off-by: Jacob Pan LKML-Reference: <1273269585-14346-1-git-send-email-jacob.jun.pan@linux.intel.com> Signed-off-by: H. Peter Anvin --- arch/x86/kernel/cpu/bugs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 01a26521239..c39576cb301 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -86,7 +86,7 @@ static void __init check_fpu(void) static void __init check_hlt(void) { - if (paravirt_enabled()) + if (boot_cpu_data.x86 >= 5 || paravirt_enabled()) return; printk(KERN_INFO "Checking 'hlt' instruction... "); -- 2.39.3