Re: [PATCH 1/1] mm: compaction: avoid fast_isolate_around() to set pageblock_skip on reserved pages

[Mel Gorman]

On Wed, Nov 25, 2020 at 03:42:37PM +0100, David Hildenbrand wrote:
> > Now the loop is for interesection of [zone_start_pfn, zone_end_pfn] with
> > memblock.memory and for x86 reserved ranges are not in memblock.memory,
> > so the memmap for them remains semi-initialized.
> 
> As far as I understood Mel, rounding these ranges up/down to cover full
> MAX_ORDER blocks/pageblocks might work.
> 

Yes, round down the lower end of the hole and round up the higher end to
the MAX_ORDER boundary for the purposes of having valid zone/node
linkages even if the underlying page is PageReserved.

-- 
Mel Gorman
SUSE Labs