[PATCH] x86: avoid check hlt for newer cpus
in [Kernel]
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From: Jacob Pan on 7 May 2010 18:10 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). http://lkml.org/lkml/2010/5/7/395 Signed-off-by: Jacob Pan <jacob.jun.pan(a)linux.intel.com> --- arch/x86/kernel/cpu/bugs.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 01a2652..36d9bcf 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 (paravirt_enabled() || boot_cpu_data.x86 > 5) return; printk(KERN_INFO "Checking 'hlt' instruction... "); -- 1.6.3.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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