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Date: Fri, 10 Dec 2004 16:19:56 +1100
From: Nick Piggin <nickpiggin@yahoo.com.au>
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To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Hugh Dickins <hugh@veritas.com>, Christoph Lameter <clameter@sgi.com>,
       Linus Torvalds <torvalds@osdl.org>, Andrew Morton <akpm@osdl.org>,
       linux-mm@kvack.org, linux-ia64@vger.kernel.org,
       Linux Kernel list <linux-kernel@vger.kernel.org>
Subject: Re: page fault scalability patch V12 [0/7]: Overview and	performance
 tests
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Benjamin Herrenschmidt wrote:
> On Fri, 2004-12-10 at 15:54 +1100, Nick Piggin wrote:
> 
>>Nick Piggin wrote:
>>
>>The page-freed-before-update_mmu_cache issue can be solved in that way,
>>not the set_pte and update_mmu_cache not performed under the same ptl
>>section issue that you raised.
> 
> 
> What is the problem with update_mmu_cache ? It doesn't need to be done
> in the same lock section since it's approx. equivalent to a HW fault,
> which doesn't take the ptl...
> 

I don't think a problem has been observed, I think Hugh was just raising
it as a general issue.