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Date: Mon, 19 Nov 2001 16:08:36 -0800 (PST)
From: Linus Torvalds <torvalds@transmeta.com>
To: Rik van Riel <riel@conectiva.com.br>
cc: Rik van Riel <riel@marcelothewonderpenguin.com>,
        Marcelo Tosatti <marcelo@conectiva.com.br>,
        Simon Kirby <sim@netnation.com>, Andrea Arcangeli <andrea@suse.de>,
        lkml <linux-kernel@vger.kernel.org>
Subject: Re: VM-related Oops: 2.4.15pre1
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On Mon, 19 Nov 2001, Rik van Riel wrote:
>
> The thing is, the "exclusively owned" situation cannot
> be checked in any way, except maybe through the fact
> that page->mapping==NULL ...

Well, you also have to check that the page isn't on the LRU list, so it
would have to be something like

	!page->mapping && !PageLRU(page)

which I agree is ugly. It's much better to just move the page->flag
setting into the callers (and most of the callers _can_ trivially check
that they are exclusive owners, because most of them will just have
allocated the page ;)

		Linus

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