Messages in this thread |  | | | From | "Rafael J. Wysocki" <> | | Subject | Re: [linux-pm] [PATCH] hibernation should work ok with memory hotplug | | Date | Tue, 4 Nov 2008 08:08:35 +0100 |
On Tuesday, 4 of November 2008, Nigel Cunningham wrote:
> Hi.> > On Mon, 2008-11-03 at 14:34 -0800, Dave Hansen wrote:
> > A node might have a node_start_pfn=0 and a node_end_pfn=100 (and it may
> > have only one zone). But, there may be another node with
> > node_start_pfn=10 and a node_end_pfn=20. This loop:
> > > > for_each_zone(zone) {
> > ...
> > for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
> > if (page_is_saveable(zone, pfn))
> > memory_bm_set_bit(orig_bm, pfn);
> > }
> >
> > will walk over the smaller node's pfn range multiple times. Is this OK?
> >
> > I think all you have to do to fix it is check page_zone(page) == zone
> > and skip out if they don't match.> > So pfn 10 in the first node refers to the same memory as pfn 10 in the
> second node?
A pfn always refers to specific page frame and/or struct page, so yes.
However, in one of the nodes these pfns are sort of "invalid" (they point
to struct pages belonging to other zones). AFAICS.
Thanks,
Rafael
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