Messages in this thread | | | Date | Wed, 26 Jul 2017 14:30:41 +0200 | From | Michal Hocko <> | Subject | Re: [RFC PATCH 3/5] mm, memory_hotplug: allocate memmap from the added memory range for sparse-vmemmap |
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On Wed 26-07-17 13:45:39, Heiko Carstens wrote: [...] > In general I do like your idea, however if I understand your patches > correctly we might have an ordering problem on s390: it is not possible to > access hot-added memory on s390 before it is online (MEM_GOING_ONLINE > succeeded).
Could you point me to the code please? I cannot seem to find the notifier which implements that.
> On MEM_GOING_ONLINE we ask the hypervisor to back the potential available > hot-added memory region with physical pages. Accessing those ranges before > that will result in an exception.
Can we make the range which backs the memmap range available? E.g from s390 specific __vmemmap_populate path?
> However with your approach the memory is still allocated when add_memory() > is being called, correct? That wouldn't be a change to the current > behaviour; except for the ordering problem outlined above.
Could you be more specific please? I do not change when the memmap is allocated.
-- Michal Hocko SUSE Labs
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