Re: [PATCH 4/4] x86: use pte_none() to test for empty PTE

From	Dave Hansen <dave.hansen@intel.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH 4/4] x86: use pte_none() to test for empty PTE
Date	2016-07-13 18:40 +0200
Message-ID	<rUvmy-5za-19@gated-at.bofh.it> (permalink)
References	<rSrGp-5Fj-5@gated-at.bofh.it> <rSrQ5-5JH-5@gated-at.bofh.it> <rUugO-4RD-27@gated-at.bofh.it> <rUuJQ-53V-23@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On 07/13/2016 08:49 AM, Julia Lawall wrote:
> My results are below.  There are a couple of cases in arch/mn10300/mm that
> were not in the original patch.

Yeah, so mn10300 is obviously unaffected by the erratum in question, and
I didn't look for non-x86 architectures for this patch.

But, this code definitely _looks_ like it should be using pte_none(),
especially since mn10300 defines it the same way as x86 (well, as x86
_did_ before this series).

	#define pte_none(x)		(!pte_val(x))

> diff -u -p a/arch/mn10300/mm/cache-inv-icache.c b/arch/mn10300/mm/cache-inv-icache.c
> --- a/arch/mn10300/mm/cache-inv-icache.c
> +++ b/arch/mn10300/mm/cache-inv-icache.c
> @@ -45,11 +45,11 @@ static void flush_icache_page_range(unsi
>  		return;
> 
>  	pud = pud_offset(pgd, start);
> -	if (!pud || !pud_val(*pud))
> +	if (!pud || pud_none(*pud))
>  		return;
> 
>  	pmd = pmd_offset(pud, start);
> -	if (!pmd || !pmd_val(*pmd))
> +	if (!pmd || pmd_none(*pmd))
>  		return;

Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

Re: [PATCH 4/4] x86: use pte_none() to test for empty PTE Michal Hocko <mhocko@kernel.org> - 2016-07-13 17:40 +0200
  Re: [PATCH 4/4] x86: use pte_none() to test for empty PTE Julia Lawall <julia.lawall@lip6.fr> - 2016-07-13 18:00 +0200
    Re: [PATCH 4/4] x86: use pte_none() to test for empty PTE Dave Hansen <dave.hansen@intel.com> - 2016-07-13 18:40 +0200

csiph-web