Re: [PATCH 5/6] mm, memory_hotplug: do not associate hotadded memory to zones until online

From: Michal Hocko
Date: Fri Mar 31 2017 - 02:50:20 EST


On Fri 31-03-17 14:18:08, Hillf Danton wrote:
>
> On March 30, 2017 7:55 PM Michal Hocko wrote:
> >
> > +static void __meminit resize_zone_range(struct zone *zone, unsigned long start_pfn,
> > + unsigned long nr_pages)
> > +{
> > + unsigned long old_end_pfn = zone_end_pfn(zone);
> > +
> > + if (start_pfn < zone->zone_start_pfn)
> > + zone->zone_start_pfn = start_pfn;
> > +
> > + zone->spanned_pages = max(start_pfn + nr_pages, old_end_pfn) - zone->zone_start_pfn;
> > +}
> The implementation above implies zone can only go bigger.

yes, we do not shrink zones currently and I see no poit in doing that
right now.

> Can we resize zone with the given data?

Why couldn't we?

--
Michal Hocko
SUSE Labs