Re: [PATCH v12 1/7] mm: hugetlb_vmemmap: disable hugetlb_optimize_vmemmap when struct page crosses page boundaries

[Oscar Salvador]

On Mon, May 16, 2022 at 06:22:05PM +0800, 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>

Reviewed-by: Oscar Salvador <osalvador@xxxxxxx>

-- 
Oscar Salvador
SUSE Labs