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Date: Fri, 1 May 2009 21:59:41 +0200
From: Ingo Molnar <mingo@elte.hu>
To: Christoph Lameter <cl@linux.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
       Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>,
       Andrew Morton <akpm@linux-foundation.org>,
       Nick Piggin <nickpiggin@yahoo.com.au>,
       KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
       Peter Zijlstra <a.p.zijlstra@chello.nl>, thomas.pi@arcor.dea,
       Yuriy Lalym <ylalym@gmail.com>,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
       ltt-dev@lists.casi.polymtl.ca, Tejun Heo <tj@kernel.org>
Subject: Re: [PATCH] Fix dirty page accounting in
	redirty_page_for_writepage()
Message-ID: <20090501195941.GA28264@elte.hu>
References: <20090430143819.GF14696@elte.hu> <alpine.DEB.1.10.0904301042170.4028@qirst.com> <20090430150142.GC20580@elte.hu> <alpine.DEB.1.10.0904301114440.4028@qirst.com> <20090430154255.GA3714@elte.hu> <alpine.DEB.1.10.0904301142140.4028@qirst.com> <20090430160606.GA5913@elte.hu> <alpine.LFD.2.00.0904300914110.3395@localhost.localdomain> <20090430172341.GA11865@elte.hu> <alpine.DEB.1.10.0904301406210.11923@qirst.com>
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* Christoph Lameter <cl@linux.com> wrote:

> On Thu, 30 Apr 2009, Ingo Molnar wrote:
> 
> > So we introduced preemption-safety in the v2 version of that commit.
> >
> > This non-atomicity will 1) either not matter 2) will be 
> > irq-atomic by virtue of being within a critical section 3) can 
> > be made atomic in the few remaining cases.
> >
> > And maybe, at most, introduce an opt-in API: 
> > percpu_add_irqsafe().
> 
> Plus percpu_add_preemptsafe().

Ok - that would be easy. Would you be interested in doing that and 
would you be interested in resurrecting your old patches? They are 
genuinely useful IMHO.

	Ingo