linux-kernel - Re: [PATCH v3 4/7] x86/tlb: add tlb flush all factor for specific CPUs

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Message-ID: <4FA93946.2000302@zytor.com>
Date:	Tue, 08 May 2012 08:18:30 -0700
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Alex Shi <alex.shi@...el.com>
CC:	mgorman@...e.de, npiggin@...il.com, tglx@...utronix.de,
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Subject: Re: [PATCH v3 4/7] x86/tlb: add tlb flush all factor for specific
 CPUs

On 05/08/2012 07:03 AM, Alex Shi wrote:
>  
> -	if (!cpu_has_invlpg || vma->vm_flags & VM_HUGETLB) {
> +	if (!cpu_has_invlpg || vma->vm_flags & VM_HUGETLB
> +				|| !tlb_flushall_factor) {

OK nevermind on the division by zero, but this yet another test being
performed.

If nothing else you could fold these tests and make tlb_flushall_factor
zero if !cpu_has_invlpg.

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.

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