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Date: Thu, 22 Apr 2010 10:14:04 -0500 (CDT)
From: Christoph Lameter <cl@linux.com>
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To: Minchan Kim <minchan.kim@gmail.com>
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Subject: Re: [PATCH 04/14] mm,migration: Allow the migration of PageSwapCache
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On Thu, 22 Apr 2010, Minchan Kim wrote:

> For further optimization, we can hold vma->adjust_lock if vma_address
> returns -EFAULT. But I hope we redesigns it without new locking.
> But I don't have good idea, now. :(

You could make it atomic through the use of RCU.

Create a new vma entry with the changed parameters and then atomically
switch to the new vma.

Problem is that you have some list_heads in there.

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