Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1697790

Re: gigantic hugepages vs. movable zones

Show all headers | View raw

On 07/27/2017 12:58 PM, Michal Hocko wrote:
> On Thu 27-07-17 07:52:08, Aneesh Kumar K.V wrote:
>> Michal Hocko <mhocko@kernel.org> writes:
>>
>>> Hi,
>>> I've just noticed that alloc_gigantic_page ignores movability of the
>>> gigantic page and it uses any existing zone. Considering that
>>> hugepage_migration_supported only supports 2MB and pgd level hugepages
>>> then 1GB pages are not migratable and as such allocating them from a
>>> movable zone will break the basic expectation of this zone. Standard
>>> hugetlb allocations try to avoid that by using htlb_alloc_mask and I
>>> believe we should do the same for gigantic pages as well.
>>>
>>> I suspect this behavior is not intentional. What do you think about the
>>> following untested patch?
>>
>>
>> I also noticed an unrelated issue with the usage of
>> start_isolate_page_range. On error we set the migrate type to
>> MIGRATE_MOVABLE.
> 
> Why that should be a problem? I think it is perfectly OK to have
> MIGRATE_MOVABLE pageblocks inside kernel zones.
> 

we can pick pages with migrate type movable and if we fail to isolate 
won't we set the migrate type of that pages to MOVABLE ?

-aneesh

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

gigantic hugepages vs. movable zones Michal Hocko <mhocko@kernel.org> - 2017-07-26 13:00 +0200
  Re: gigantic hugepages vs. movable zones "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> - 2017-07-27 04:30 +0200
    Re: gigantic hugepages vs. movable zones Michal Hocko <mhocko@kernel.org> - 2017-07-27 09:30 +0200
      Re: gigantic hugepages vs. movable zones "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> - 2017-07-27 10:10 +0200
        Re: gigantic hugepages vs. movable zones Michal Hocko <mhocko@kernel.org> - 2017-07-27 10:20 +0200
          Re: gigantic hugepages vs. movable zones Michal Hocko <mhocko@kernel.org> - 2017-07-27 10:30 +0200
            Re: gigantic hugepages vs. movable zones Vlastimil Babka <vbabka@suse.cz> - 2017-07-27 14:00 +0200
  Re: gigantic hugepages vs. movable zones Mike Kravetz <mike.kravetz@oracle.com> - 2017-07-28 22:50 +0200
    Re: gigantic hugepages vs. movable zones Michal Hocko <mhocko@kernel.org> - 2017-07-31 08:50 +0200

csiph-web