From mboxrd@z Thu Jan  1 00:00:00 1970
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Subject: Re: [PATCH 1 of 4] mm: add a ptep_modify_prot transaction
	abstraction
Date: Thu, 19 Jun 2008 10:39:31 +1000
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To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>, xen-devel <xen-devel@lists.xensource.com>, Peter Zijlstra <a.p.zijlstra@chello.nl>, kvm-devel <kvm-devel@lists.sourceforge.net>, x86@kernel.org, LKML <linux-kernel@vger.kernel.org>, Virtualization Mailing List <virtualization@lists.osdl.org>, Hugh Dickins <hugh@veritas.com>, Ingo Molnar <mingo@elte.hu>, Thomas Gleixner <tglx@linutronix.de>
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On Wed, 2008-06-18 at 17:24 -0700, Linus Torvalds wrote:
> 
> On Wed, 18 Jun 2008, Jeremy Fitzhardinge wrote:
> >
> > Along the lines of:
> 
> Hell no. There's a reason we have a special set_wrprotect() thing. We can 
> do it more efficiently on native hardware by just clearing the bit 
> atomically. No need to do the cmpxchg games.

But we can't batch ... 

Ben.