From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Mel Gorman <mgorman@suse.de>
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>,
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 03/10] mm: Convert p[te|md]_numa users to p[te|md]_protnone_numa
Date: Tue, 02 Dec 2014 12:57:00 +0530 [thread overview]
Message-ID: <87k32ah5q3.fsf@linux.vnet.ibm.com> (raw)
In-Reply-To: <1417473762.7182.8.camel@kernel.crashing.org>
Benjamin Herrenschmidt <benh@kernel.crashing.org> writes:
> On Fri, 2014-11-21 at 13:57 +0000, Mel Gorman wrote:
>> Convert existing users of pte_numa and friends to the new helper. Note
>> that the kernel is broken after this patch is applied until the other
>> page table modifiers are also altered. This patch layout is to make
>> review easier.
>
> Aneesh, the removal of the DSISR_PROTFAULT checks, I wonder if we might
> break something here ... (I know, I asked for them to be removed :-)
>
That is the reason I converted that to a WARN_ON in later patch.
> IE, we basically bounce all protection checks to the "normal" VMA
> protection checking, so far so good...
>
> But what about the subpage protection stuff ? Will that still work ?
>
I did look at that before. So if we had subpage access limitted, when we
take a fault for that subpage, we bail out early in hash_page_mm. (with
rc = 2). low_hash_fault handle that case directly. We will not end up
calling do_page_fault.
Now, hash_preload can possibly insert an hpte in hash page table even if
the access is not allowed by the pte permissions. But i guess even that
is ok. because we will fault again, end-up calling hash_page_mm where we
handle that part correctly.
-aneesh
next prev parent reply other threads:[~2014-12-02 7:27 UTC|newest]
Thread overview: 31+ 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
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 [this message]
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 03/10] mm: Convert p[te|md]_numa users to p[te|md]_protnone_numa 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 03/10] mm: Convert p[te|md]_numa users to p[te|md]_protnone_numa 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 03/10] mm: Convert p[te|md]_numa users to p[te|md]_protnone_numa Mel Gorman
2014-11-20 10:38 ` David Laight
2014-11-20 10:47 ` Mel Gorman
2014-11-21 5:28 ` Aneesh Kumar K.V
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