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Subject: Re: 2.6.13-rc3-mm3
From: Richard Purdie <rpurdie@rpsys.net>
To: Christoph Lameter <christoph@lameter.com>
Cc: Andrew Morton <akpm@osdl.org>, linux-kernel@vger.kernel.org,
       nickpiggin@yahoo.com.au
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Date: Sun, 07 Aug 2005 14:44:35 +0100
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On Fri, 2005-08-05 at 08:17 -0700, Christoph Lameter wrote:
> On Thu, 4 Aug 2005, Richard Purdie wrote:
> > 
> > We know the the failure case can be identified by the
> > cmpxchg_fail_flag_update condition being met. Can you provide me with a
> > patch to dump useful debugging information when that occurs?
> 
> Well yes simply print out the information available in that context.
> 
> +		printk(KERN_CRIT "cmpxchg fail mm=%p vma=%p addr=%lx write=%d ptep=%p pmd=%p entry=%lx new=%lx\n",
> +				mm, vma, address, write_access, pte, pmd, pte_val(entry), pte_val(new_entry));

Ok, this results in an infinite loop of one message with no change to
the numbers:

cmpxchg fail mm=c3455ae0 vma=c355517c addr=4025f000 write=2048
ptep=c2f0597c pmd=c2b79008 entry=88000f7 new=8800077

Richard