Re: [RFC PATCH 0/5] mm, memory_hotplug: allocate memmap from hotadded memory

From	Michal Hocko <mhocko@kernel.org>
Newsgroups	linux.kernel
Subject	Re: [RFC PATCH 0/5] mm, memory_hotplug: allocate memmap from hotadded memory
Date	2017-07-28 14:10 +0200
Message-ID	<u8cfD-3AM-1@gated-at.bofh.it> (permalink)
References	<u7q1j-6pF-3@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Wed 26-07-17 10:33:28, Michal Hocko wrote:
[...]
> There is also one potential drawback, though. If somebody uses memory
> hotplug for 1G (gigantic) hugetlb pages then this scheme will not work
> for them obviously because each memory section will contain 2MB reserved
> area.

Actually I am wrong here. It is not each section in general. I have
completely forgot that we do large memblocks on x86_64 with a lot of
memory and then we hotadd 2GB memblocks and the altmap will allocate
from the beginign of the _memblock_ and so all the memmaps will end up
in the first memory section.
-- 
Michal Hocko
SUSE Labs

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[RFC PATCH 0/5] mm, memory_hotplug: allocate memmap from hotadded memory Michal Hocko <mhocko@kernel.org> - 2017-07-26 10:40 +0200
  [RFC PATCH 4/5] mm, sparse: complain about implicit altmap usage in vmemmap_populate Michal Hocko <mhocko@kernel.org> - 2017-07-26 10:40 +0200
  [RFC PATCH 1/5] mm, memory_hotplug: cleanup memory offline path Michal Hocko <mhocko@kernel.org> - 2017-07-26 10:40 +0200
  Re: [RFC PATCH 0/5] mm, memory_hotplug: allocate memmap from  hotadded memory Michal Hocko <mhocko@kernel.org> - 2017-07-26 13:50 +0200
  Re: [RFC PATCH 0/5] mm, memory_hotplug: allocate memmap from  hotadded memory Jerome Glisse <jglisse@redhat.com> - 2017-07-26 23:10 +0200
    Re: [RFC PATCH 0/5] mm, memory_hotplug: allocate memmap from  hotadded memory Michal Hocko <mhocko@kernel.org> - 2017-07-27 09:00 +0200
      Re: [RFC PATCH 0/5] mm, memory_hotplug: allocate memmap from  hotadded memory Michal Hocko <mhocko@kernel.org> - 2017-07-28 14:20 +0200
  Re: [RFC PATCH 0/5] mm, memory_hotplug: allocate memmap from  hotadded memory Michal Hocko <mhocko@kernel.org> - 2017-07-28 14:10 +0200

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