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Date: Fri, 11 May 2007 09:17:44 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
       Oleg Nesterov <oleg@tv-sign.ru>, Ingo Molnar <mingo@elte.hu>,
       Thomas Gleixner <tglx@linutronix.de>, Nick Piggin <npiggin@suse.de>
Subject: Re: [PATCH 2/2] mm: change mmap_sem over to the scalable rw_mutex
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	<20070511132321.984615201@chello.nl>
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On Fri, 11 May 2007 15:15:43 +0200 Peter Zijlstra <a.p.zijlstra@chello.nl> wrote:

> -	down_write(&current->mm->mmap_sem);
> +	rw_mutex_write_lock(&current->mm->mmap_lock);

y'know, this is such an important lock and people have had such problems
with it and so many different schemes and ideas have popped up that I'm
kinda thinking that we should wrap it:

	write_lock_mm(struct mm_struct *mm);
	write_unlock_mm(struct mm_struct *mm);
	read_lock_mm(struct mm_struct *mm);
	read_unlock_mm(struct mm_struct *mm);

so that further experimentations become easier?