Re: 答复: 答复: [PATCH V2] vfio dma_map/unmap: optimized for hugetlbfs pages

[Jason Wang]

On 2020/8/28 下午10:24, Peter Xu wrote:
> On Fri, Aug 28, 2020 at 09:23:08AM +0000, Maoming (maoming, Cloud Infrastructure Service Product Dept.) wrote:
> > In hugetlb_put_pfn(), I delete unpin_user_pages_dirty_lock() and use some simple code to put hugetlb pages.
> > Is this right?
> I think we should still use the APIs because of the the same reason.  However
> again I don't know the performance impact of that to your patch, but I still
> think that could be done inside gup itself when needed (e.g., a special path
> for hugetlbfs for [un]pinning continuous pages; though if that's the case that
> could be something to be discussed on -mm then as a separate patch, imho).
>
> Thanks,


+1, we should make this as a generic optimization instead of VFIO 
specific consider there're a lot of GUP users.

Thanks