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From: Dave Hansen <dave.hansen@intel.com>
To: Julia Lawall <julia.lawall@lip6.fr>, Michal Hocko <mhocko@kernel.org>
Cc: linux-kernel@vger.kernel.org, x86@kernel.org, linux-mm@kvack.org,
	torvalds@linux-foundation.org, akpm@linux-foundation.org,
	bp@alien8.de, ak@linux.intel.com, dave.hansen@intel.com,
	David Howells <dhowells@redhat.com>
Subject: Re: [PATCH 4/4] x86: use pte_none() to test for empty PTE
Date: Wed, 13 Jul 2016 09:28:18 -0700	[thread overview]
Message-ID: <57866C22.4040402@intel.com> (raw)
In-Reply-To: <alpine.DEB.2.10.1607131746570.2959@hadrien>

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;


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WARNING: multiple messages have this Message-ID (diff)
From: Dave Hansen <dave.hansen@intel.com>
To: Julia Lawall <julia.lawall@lip6.fr>, Michal Hocko <mhocko@kernel.org>
Cc: linux-kernel@vger.kernel.org, x86@kernel.org, linux-mm@kvack.org,
	torvalds@linux-foundation.org, akpm@linux-foundation.org,
	bp@alien8.de, ak@linux.intel.com, dave.hansen@intel.com,
	David Howells <dhowells@redhat.com>
Subject: Re: [PATCH 4/4] x86: use pte_none() to test for empty PTE
Date: Wed, 13 Jul 2016 09:28:18 -0700	[thread overview]
Message-ID: <57866C22.4040402@intel.com> (raw)
In-Reply-To: <alpine.DEB.2.10.1607131746570.2959@hadrien>

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;

  reply	other threads:[~2016-07-13 16:29 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-07-08  0:19 [PATCH 0/4] [RFC][v4] Workaround for Xeon Phi PTE A/D bits erratum Dave Hansen
2016-07-08  0:19 ` Dave Hansen
2016-07-08  0:19 ` [PATCH 1/4] x86, swap: move swap offset/type up in PTE to work around erratum Dave Hansen
2016-07-08  0:19   ` Dave Hansen
2016-07-13  8:03   ` [tip:x86/mm] x86/mm: Move " tip-bot for Dave Hansen
2016-07-13 15:19   ` [PATCH 1/4] x86, swap: move " Michal Hocko
2016-07-13 15:19     ` Michal Hocko
2016-07-08  0:19 ` [PATCH 2/4] x86, pagetable: ignore A/D bits in pte/pmd/pud_none() Dave Hansen
2016-07-08  0:19   ` Dave Hansen
2016-07-13  8:03   ` [tip:x86/mm] x86/mm: Ignore " tip-bot for Dave Hansen
2016-07-13 15:21   ` [PATCH 2/4] x86, pagetable: ignore " Michal Hocko
2016-07-13 15:21     ` Michal Hocko
2016-07-13 15:47     ` Dave Hansen
2016-07-13 15:47       ` Dave Hansen
2016-07-14  6:13       ` Michal Hocko
2016-07-14  6:13         ` Michal Hocko
2016-07-08  0:19 ` [PATCH 3/4] x86: disallow running with 32-bit PTEs to work around erratum Dave Hansen
2016-07-08  0:19   ` Dave Hansen
2016-07-13  8:04   ` [tip:x86/mm] x86/mm: Disallow " tip-bot for Dave Hansen
2016-07-08  0:19 ` [PATCH 4/4] x86: use pte_none() to test for empty PTE Dave Hansen
2016-07-08  0:19   ` Dave Hansen
2016-07-13  8:04   ` [tip:x86/mm] x86/mm: Use " tip-bot for Dave Hansen
2016-07-13 15:18   ` [PATCH 4/4] x86: use " Michal Hocko
2016-07-13 15:18     ` Michal Hocko
2016-07-13 15:23     ` Julia Lawall
2016-07-13 15:23       ` Julia Lawall
2016-07-13 15:49     ` Julia Lawall
2016-07-13 15:49       ` Julia Lawall
2016-07-13 16:28       ` Dave Hansen [this message]
2016-07-13 16:28         ` Dave Hansen
2016-07-14 13:47   ` Vlastimil Babka
2016-07-14 13:47     ` Vlastimil Babka
2016-07-14 14:24     ` Dave Hansen
2016-07-14 14:24       ` Dave Hansen
2016-07-14 14:50       ` David Vrabel
2016-07-14 14:50         ` David Vrabel
2016-07-13  9:54 ` [PATCH 0/4] [RFC][v4] Workaround for Xeon Phi PTE A/D bits erratum Vlastimil Babka
2016-07-13  9:54   ` Vlastimil Babka
  -- strict thread matches above, loose matches on Subject: below --
2016-07-01 17:46 Dave Hansen
2016-07-01 17:47 ` [PATCH 4/4] x86: use pte_none() to test for empty PTE Dave Hansen
2016-07-01 17:47   ` Dave Hansen

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