Re: [PATCH v15 00/11] migrate on fault for device pages

[Mika Penttilä]

On 9/25/26 15:47, Jason Gunthorpe wrote:
> On Fri, Sep 25, 2026 at 01:23:52PM +0300, Mika Penttilä wrote:
>> On 9/25/26 12:07, Christoph Hellwig wrote:
>>> Who is going to use this? The series seems to lack an actual user
>>> for it. 
>> Two users: For one, existing migrate_vma_setup() callers, unchanged.
>> The series reworks migrate_vma_setup() to collect via
>> hmm_range_fault() internally (it sets HMM_PFN_REQ_MIGRATE and calls
>> migrate_hmm_range_setup(), mm/migrate_device.c). So every in-tree
>> migrate_vma consumer — nouveau, amdgpu/amdkfd, drm/xe via
>> drm_pagemap, lib/test_hmm — runs on the new path. 
> So split the series so you don't add unused interfaces for now? Jason

I think we get the other for "free", migrate_vma_setup() ->
hmm_range_fault() is the now used. But if wanted you can drive the
migration initially from  hmm_range_fault()  also from fault handler. If
don't want that then it's removing 
EXPORT_SYMBOL(migrate_hmm_range_setup);

--Mika