From: Mel Gorman <mgorman@suse.de>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rik van Riel <riel@redhat.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Hugh Dickins <hughd@google.com>,
Linux Kernel <linux-kernel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>, Ingo Molnar <mingo@redhat.com>,
Paul Mackerras <paulus@samba.org>,
Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>,
Sasha Levin <sasha.levin@oracle.com>,
Dave Jones <davej@redhat.com>,
LinuxPPC-dev <linuxppc-dev@lists.ozlabs.org>,
Kirill Shutemov <kirill.shutemov@linux.intel.com>
Subject: Re: [PATCH 02/10] mm: Add p[te|md] protnone helpers for use by NUMA balancing
Date: Tue, 2 Dec 2014 10:12:10 +0000 [thread overview]
Message-ID: <20141202101210.GA6043@suse.de> (raw)
In-Reply-To: <1417473519.7182.6.camel@kernel.crashing.org>
On Tue, Dec 02, 2014 at 09:38:39AM +1100, Benjamin Herrenschmidt wrote:
> On Fri, 2014-11-21 at 13:57 +0000, Mel Gorman wrote:
>
> > #ifdef CONFIG_NUMA_BALANCING
> > +/*
> > + * These work without NUMA balancing but the kernel does not care. See the
> > + * comment in include/asm-generic/pgtable.h
> > + */
> > +static inline int pte_protnone(pte_t pte)
> > +{
> > + return (pte_val(pte) &
> > + (_PAGE_PRESENT | _PAGE_USER)) == _PAGE_PRESENT;
> > +}
>
> I would add a comment clarifying that this only works for user pages,
> ie, this accessor will always return "true" for a kernel page on ppc.
>
diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
index 490bd6d..7b889a3 100644
--- a/arch/powerpc/include/asm/pgtable.h
+++ b/arch/powerpc/include/asm/pgtable.h
@@ -41,7 +41,8 @@ static inline pgprot_t pte_pgprot(pte_t pte) { return __pgprot(pte_val(pte) & PA
#ifdef CONFIG_NUMA_BALANCING
/*
* These work without NUMA balancing but the kernel does not care. See the
- * comment in include/asm-generic/pgtable.h
+ * comment in include/asm-generic/pgtable.h . On powerpc, this will only
+ * work for user pages and always return true for kernel pages.
*/
static inline int pte_protnone(pte_t pte)
{
--
Mel Gorman
SUSE Labs
next prev parent reply other threads:[~2014-12-02 10:12 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-21 13:57 [PATCH 0/10] Replace _PAGE_NUMA with PAGE_NONE protections v3 Mel Gorman
2014-11-21 13:57 ` [PATCH 01/10] mm: numa: Do not dereference pmd outside of the lock during NUMA hinting fault Mel Gorman
2014-11-21 13:57 ` [PATCH 02/10] mm: Add p[te|md] protnone helpers for use by NUMA balancing Mel Gorman
2014-12-01 22:38 ` Benjamin Herrenschmidt
2014-12-02 10:12 ` Mel Gorman [this message]
2014-11-21 13:57 ` [PATCH 03/10] mm: Convert p[te|md]_numa users to p[te|md]_protnone_numa Mel Gorman
2014-12-01 22:42 ` Benjamin Herrenschmidt
2014-12-02 7:27 ` Aneesh Kumar K.V
2014-12-02 20:11 ` Benjamin Herrenschmidt
2014-12-03 15:23 ` Aneesh Kumar K.V
2014-12-03 15:52 ` Mel Gorman
2014-12-03 17:20 ` Aneesh Kumar K.V
2014-12-04 11:17 ` Mel Gorman
2014-12-03 21:01 ` Benjamin Herrenschmidt
2014-12-04 11:15 ` Mel Gorman
2014-12-01 22:44 ` Benjamin Herrenschmidt
2014-12-02 7:31 ` Aneesh Kumar K.V
2014-12-02 20:13 ` Benjamin Herrenschmidt
2014-11-21 13:57 ` [PATCH 04/10] ppc64: Add paranoid warnings for unexpected DSISR_PROTFAULT Mel Gorman
2014-11-21 13:57 ` [PATCH 05/10] mm: Convert p[te|md]_mknonnuma and remaining page table manipulations Mel Gorman
2014-11-21 13:57 ` [PATCH 06/10] mm: Remove remaining references to NUMA hinting bits and helpers Mel Gorman
2014-11-21 13:57 ` [PATCH 07/10] mm: numa: Do not trap faults on the huge zero page Mel Gorman
2014-11-21 13:57 ` [PATCH 08/10] x86: mm: Restore original pte_special check Mel Gorman
2014-11-21 13:57 ` [PATCH 09/10] mm: numa: Add paranoid check around pte_protnone_numa Mel Gorman
2014-11-21 13:57 ` [PATCH 10/10] mm: numa: Avoid unnecessary TLB flushes when setting NUMA hinting entries Mel Gorman
-- strict thread matches above, loose matches on Subject: below --
2015-01-05 10:54 [PATCH 0/10] Replace _PAGE_NUMA with PAGE_NONE protections v5 Mel Gorman
2015-01-05 10:54 ` [PATCH 02/10] mm: Add p[te|md] protnone helpers for use by NUMA balancing Mel Gorman
2014-12-04 11:24 [PATCH 0/10] Replace _PAGE_NUMA with PAGE_NONE protections v4 Mel Gorman
2014-12-04 11:24 ` [PATCH 02/10] mm: Add p[te|md] protnone helpers for use by NUMA balancing Mel Gorman
2014-11-20 10:19 [PATCH 0/10] Replace _PAGE_NUMA with PAGE_NONE protections v2 Mel Gorman
2014-11-20 10:19 ` [PATCH 02/10] mm: Add p[te|md] protnone helpers for use by NUMA balancing Mel Gorman
2014-11-20 19:54 ` Linus Torvalds
2014-11-21 9:35 ` Mel Gorman
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