Date: Tue, 5 Jan 2010 09:28:36 +0900
From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
To: Christoph Lameter <cl@linux-foundation.org>
Cc: Rik van Riel <riel@redhat.com>, Peter Zijlstra <a.p.zijlstra@chello.nl>,
       "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
       Peter Zijlstra <peterz@infradead.org>,
       "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
       "linux-mm@kvack.org" <linux-mm@kvack.org>,
       "minchan.kim@gmail.com" <minchan.kim@gmail.com>,
       "hugh.dickins" <hugh.dickins@tiscali.co.uk>,
       Nick Piggin <nickpiggin@yahoo.com.au>, Ingo Molnar <mingo@elte.hu>,
       Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [RFC][PATCH 0/8] Speculative pagefault -v3
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	<4B42606F.3000906@redhat.com>
	<alpine.DEB.2.00.1001041558350.17041@router.home>
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On Mon, 4 Jan 2010 15:59:45 -0600 (CST)
Christoph Lameter <cl@linux-foundation.org> wrote:

> On Mon, 4 Jan 2010, Rik van Riel wrote:
> 
> > Fun, but why do we need this?
> >
> > What improvements did you measure?
> 
> If it measures up to Kame-sans approach then the possible pagefault rate
> will at least double ...
> 
On 4-core/2 socket machine ;)

More than page fault rate, important fact is that we can reduce cache contention
by skipping mmap_sem in some situation.

And I think we have some chances.

Thanks,
-Kame

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