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Date: Mon, 2 Feb 2009 14:12:30 -0800 (PST)
From: Linus Torvalds <torvalds@linux-foundation.org>
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To: Mel Gorman <mel@csn.ul.ie>
cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
       Hugh Dickins <hugh@veritas.com>,
       Lee Schermerhorn <Lee.Schermerhorn@hp.com>, Greg KH <gregkh@suse.de>,
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       KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
       Mikos Szeredi <miklos@szeredi.hu>, Andy Whitcroft <apw@canonical.com>
Subject: Re: [PATCH] Fix OOPS in mmap_region() when merging adjacent VM_LOCKED
 file segments
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On Mon, 2 Feb 2009, Mel Gorman wrote:
> 
> Lets say someone does the following
> 
> 1. mmap(PROT_READ, MAP_PRIVATE) on a hugetlbfs file
> 	VM_ACCOUNT is not set for hugetlbfs
> 	VM_NORESERVE is not set because MAP_NORESERVE was not there

But isn't this exactly the thing that we have that odd "accountable" flag 
for, and we do the whole

	if (!accountable)
		vm_flags |= VM_NORESERVE;

in mmap_region() for?

So VM_NORESERVE _will_ be set.

				Linus