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Date: Mon, 1 Aug 2005 15:02:49 -0700 (PDT)
From: Christoph Lameter <christoph@lameter.com>
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To: Richard Purdie <rpurdie@rpsys.net>
cc: Andrew Morton <akpm@osdl.org>, linux-kernel@vger.kernel.org
Subject: Re: 2.6.13-rc3-mm3
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On Mon, 1 Aug 2005, Richard Purdie wrote:

> cmpxchg_fail_flag_update 1359210189
> 
> That number rapidly increases and so it looks like something is failing
> and looping...

That looks like some trouble with the MMU. The time between pte read and 
write has been shortened through the page fault scalability patches. 

Does this patch fix it?

Index: linux-2.6.13-rc4-mm1/mm/memory.c
===================================================================
--- linux-2.6.13-rc4-mm1.orig/mm/memory.c	2005-08-01 12:59:49.000000000 -0700
+++ linux-2.6.13-rc4-mm1/mm/memory.c	2005-08-01 15:02:19.000000000 -0700
@@ -2105,6 +2105,7 @@
 		lazy_mmu_prot_update(entry);
 	} else {
 		inc_page_state(cmpxchg_fail_flag_update);
+		set_pte_at(mm, address, pte, new_entry);
 	}
 
 	pte_unmap(pte);