Re: [RFC][patch 0/2] mm: remove PageReserved

Nick Piggin
2005-08-09T04:59:53Z

Nigel Cunningham wrote:
> Hi.
>
> On Tue, 2005-08-09 at 07:09, Daniel Phillips wrote:
>
>>>It doesn't look like they'll be able to easily free up a page
>>>flag for 2 reasons. First, PageReserved will probably be kept
>>>around for at least one release. Second, swsusp and some arch
>>>code (ioremap) wants to know about struct pages that don't point
>>>to valid RAM - currently they use PageReserved, but we'll probably
>>>just introduce a PageValidRAM or something when PageReserved goes.
>
>
> Changing the e820 code so it sets PageNosave instead of PageReserved,
> along with a couple of modifications in swsusp itself should get rid of
> the swsusp dependency.
>

That would work for swsusp, but there are other users that want to
know if a struct page is valid ram (eg. ioremap), so in that case
swsusp would not be able to mess with the flag.

I do think swsusp should (and can, quite easily though I may have
missed something) consolidate PG_nosave and PG_nosave_free, however
that's out of the scope of this patch.

Thanks,
Nick

--
SUSE Labs, Novell Inc.

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