Date: Fri, 30 Jan 2009 13:25:41 -0800 (PST)
From: Linus Torvalds <torvalds@linux-foundation.org>
To: Hugh Dickins <hugh@veritas.com>
cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>, Greg KH <gregkh@suse.de>,
       Maksim Yevmenkin <maksim.yevmenkin@gmail.com>,
       linux-kernel <linux-kernel@vger.kernel.org>,
       Nick Piggin <npiggin@suse.de>,
       Andrew Morton <akpm@linux-foundation.org>, will@crowder-design.com,
       Rik van Riel <riel@redhat.com>,
       KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
       KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
       Mikos Szeredi <miklos@szeredi.hu>
Subject: Re: [PATCH] Fix OOPS in mmap_region() when merging adjacent VM_LOCKED
 file segments
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On Fri, 30 Jan 2009, Hugh Dickins wrote:
> 
> But I'm caring more about that VM_ACCOUNT...

The bright side here is that I think the VM_ACCOUNT bit differences only 
really happen for MAP_SHARED file mappings. For MAP_SHARED anon mappings 
we already don't share (for other reasons), and for private mappings 
VM_ACCOUNT looks stable (ie it's reliably either set or not, and stays 
that way).

So the impact is reasonably low. But it would definitely be good to clean 
up that whole VM_ACCOUNT logic, and incidentally then fix that merging 
issue at the same time.

			Linus
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