Nick Piggin wrote:

I'm currently playing around with trying to reuse an existing flag
to get this information (instead of PageReserved). But it doesn't seem
like a big problem if we have to fall back to the above.

OK, with the attached patch (on top of the PageReserved removal patches)
things work nicely. However I'm not sure that I really like the use of
flags == 0xffffffff to indicate the page is unusable. For one thing it
may confuse things that walk physical pages, and for another it can
easily break if someone clears a flag of an 'unusable' page.

-- 
SUSE Labs, Novell Inc.