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Date: Thu, 13 Sep 2012 15:46:30 -0700
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Subject: Re: BUG at mm/huge_memory.c:1428!
From: Michel Lespinasse <walken@google.com>
To: Jiri Slaby <jslaby@suse.cz>
Cc: linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Jiri Slaby <jirislaby@gmail.com>
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On Thu, Sep 13, 2012 at 11:14 AM, Jiri Slaby <jslaby@suse.cz> wrote:
> Hi,
>
> I've just get the following BUG with today's -next. It happens every
> time I try to update packages.
>
> kernel BUG at mm/huge_memory.c:1428!

That is very likely my bug.

Do you have the message that should be printed right above the bug ?
(                printk(KERN_ERR "mapcount %d page_mapcount %d\n",
                       mapcount, page_mapcount(page));
)

Do you get any errors if building with CONFIG_DEBUG_VM and CONFIG_DEBUG_VM_RB ?

Does it go away if you revert "mm: avoid taking rmap locks in
move_ptes()" (cc0eac2e50f036d4d798b18679ca2ae3c4828105 in the -next
version I have here) ?

-- 
Michel "Walken" Lespinasse
A program is never fully debugged until the last user dies.