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Commit 2b107d93 authored by Jacob Pan's avatar Jacob Pan Committed by H. Peter Anvin
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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: default avatarJacob Pan <jacob.jun.pan@linux.intel.com>
LKML-Reference: <1273269585-14346-1-git-send-email-jacob.jun.pan@linux.intel.com>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
parent 722154e4

arch/x86/kernel/cpu/bugs.c

+1 −1
Original line number Original line Diff line number Diff line
@@ -86,7 +86,7 @@ static void __init check_fpu(void) 




static void __init check_hlt(void)

static void __init check_hlt(void)

{

{

	if (paravirt_enabled())

	if (boot_cpu_data.x86 >= 5 || paravirt_enabled())

		return;

		return;





	printk(KERN_INFO "Checking 'hlt' instruction... ");

	printk(KERN_INFO "Checking 'hlt' instruction... ");