Re: [RFC PATCH 3/3] hugetlb: Lazy page table copies in fork()

[David Hildenbrand]

On 28.05.22 00:58, Mike Kravetz wrote:
> Lazy page table copying at fork time was introduced with commit
> d992895ba2b2 ("Lazy page table copies in fork()").  At the time,
> hugetlb was very new and did not support page faulting.  As a result,
> it was excluded.  When full page fault support was added for hugetlb,
> the exclusion was not removed.
> 
> Simply remove the check that prevents lazy copying of hugetlb page
> tables at fork.  Of course, like other mappings this only applies to
> shared mappings.
> 
> Lazy page table copying at fork will be less advantageous for hugetlb
> mappings because:
> - There are fewer page table entries with hugetlb
> - hugetlb pmds can be shared instead of copied
> 
> In any case, completely eliminating the copy at fork time shold speed
> things up.

+ make hugetlb less special, at least a tiny little bit


Acked-by: David Hildenbrand <david@xxxxxxxxxx>

-- 
Thanks,

David / dhildenb