Re: [RFC 00/11] THP support for zone device pages

[Balbir Singh <balbirs@nvidia.com>]

On 3/7/25 10:08, Matthew Brost wrote:
> On Thu, Mar 06, 2025 at 03:42:28PM +1100, Balbir Singh wrote:
> 
> This is an exciting series to see. As of today, we have just merged this
> series into the DRM subsystem / Xe [2], which adds very basic SVM
> support. One of the performance bottlenecks we quickly identified was
> the lack of THP for device pages—I believe our profiling showed that 96%
> of the time spent on 2M page GPU faults was within the migrate_vma_*
> functions. Presumably, this will help significantly.
> 
> We will likely attempt to pull this code into GPU SVM / Xe fairly soon.
> I believe we will encounter a conflict since [2] includes these patches
> [3] [4], but we should be able to resolve that. These patches might make
> it into the 6.15 PR — TBD but I can get back to you on that.
> 
> I have one question—does this series contain all the required core MM
> changes for us to give it a try? That is, do I need to include any other
> code from the list to test this out?
> 

Thank you, the patches are built on top of mm-everything-2025-03-04-05-51, which
includes changes by Alistair to fix fs/dax reference counting and changes
By Zi Yan (folio split changes), the series builds on top of those, but the
patches are not dependent on the folio split changes, IIRC

Please do report bugs/issues that you come across.

Balbir