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Date: Tue, 8 Jan 2013 18:31:41 +0200
From: "Kirill A. Shutemov" <kirill@shutemov.name>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Hillf Danton <dhillf@gmail.com>, Hugh Dickins <hughd@google.com>,
        Dave Jones <davej@redhat.com>,
        Linux Kernel <linux-kernel@vger.kernel.org>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Mel Gorman <mgorman@suse.de>, Linux-MM <linux-mm@kvack.org>
Subject: Re: oops in copy_page_rep()
Message-ID: <20130108163141.GA27555@shutemov.name>
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On Tue, Jan 08, 2013 at 07:37:06AM -0800, Linus Torvalds wrote:
> On Tue, Jan 8, 2013 at 5:04 AM, Hillf Danton <dhillf@gmail.com> wrote:
> > On Tue, Jan 8, 2013 at 1:34 AM, Linus Torvalds
> > <torvalds@linux-foundation.org> wrote:
> >>
> >> Hmm. Is there some reason we never need to worry about it for the
> >> "pmd_numa()" case just above?
> >>
> >> A comment about this all might be a really good idea.
> >>
> > Yes Sir, added.
> 
> Heh. I was more thinking about why do_huge_pmd_wp_page() needs it, but
> do_huge_pmd_numa_page() does not.

It does. The check should be moved up.

> Also, do we actually need it for huge_pmd_set_accessed()? The
> *placement* of that thing confuses me. And because it confuses me, I'd
> like to understand it.

We need it for huge_pmd_set_accessed() too.

Looks like a mis-merge. The original patch for huge_pmd_set_accessed() was
correct: http://lkml.org/lkml/2012/10/25/402

-- 
 Kirill A. Shutemov