Re: [PATCH] mm: thp: register mm for khugepaged when merging vma for shmem

[Yang Shi]

On 6/21/18 3:10 PM, Kirill A. Shutemov wrote:
> On Fri, Jun 22, 2018 at 05:40:47AM +0800, Yang Shi wrote:
> > When merging anonymous page vma, if the size of vam can fit in at least
> s/vam/vma/
>
> > one hugepage, the mm will be registered for khugepaged for collapsing
> > THP in the future.
> >
> > But, it skips shmem vma. Doing so for shmem too when merging vma in
> > order to increase the odd to collapse hugepage by khugepaged.
> Good catch. Thanks.
>
> I think the fix incomplete. We shouldn't require vma->anon_vma for shmem,
> only for anonymous mappings. We don't support file-private THPs.

So you mean, shmem_file(vma->vm_file) && PageAnon(page)?

> > Also increase the count of shmem THP collapse. It looks missed before.
> Separate patch, please.

Sure.

Thanks,
Yang

>