Messages in this thread | | | Date | Thu, 18 Mar 2021 09:27:48 +0100 | From | Oscar Salvador <> | Subject | Re: [PATCH v4 1/5] mm,memory_hotplug: Allocate memmap from the added memory range |
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On Wed, Mar 17, 2021 at 03:35:41PM +0100, David Hildenbrand wrote: > Just assume you have two ranges > > [ ZONE_DEVICE 0 ][ ZONE_DEVICE 1] > > If the vmemmap of ZONE_DEVICE 1 could be taken from the altmap of > ZONE_DEVICE 0, we could be in trouble, as both parts can be > removed/repurposed independently ...
I have to say my knowledge about ZONE_DEVICE and its intrinsencs tend to 0, that is why I thought it might not matter, but I agree that this is only asking for trouble.
> If we check for > > IS_ALIGNED(nr_vmemmap_pages, PMD_SIZE), please add a proper TODO comment > that this is most probably the wrong place to take care of this.
Sure, I will stuff the check in there and place a big TODO comment so we do not forget about addressing this issue the right way.
I will prepare a v5 (hopefully the last one) and do some more testing before sending it out.
Thanks David!
-- Oscar Salvador SUSE L3
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