Re: [PATCH v10 1/4] mm: hugetlb_vmemmap: disable hugetlb_optimize_vmemmap when struct page crosses page boundaries

From: David Hildenbrand
Date: Thu May 12 2022 - 03:35:27 EST


On 09.05.22 08:27, Muchun Song wrote:
> If the size of "struct page" is not the power of two but with the feature
> of minimizing overhead of struct page associated with each HugeTLB is
> enabled, then the vmemmap pages of HugeTLB will be corrupted after
> remapping (panic is about to happen in theory). But this only exists when
> !CONFIG_MEMCG && !CONFIG_SLUB on x86_64. However, it is not a conventional
> configuration nowadays. So it is not a real word issue, just the result
> of a code review.
>
> But we cannot prevent anyone from configuring that combined configure.
> This hugetlb_optimize_vmemmap should be disable in this case to fix this
> issue.
>
> Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
> Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>

Acked-by: David Hildenbrand <david@xxxxxxxxxx>


--
Thanks,

David / dhildenb