Re: [PATCH v2 0/5] mm/migrate: avoid device private invalidations

[Jason Gunthorpe]

On Mon, Jul 13, 2020 at 10:21:44AM -0700, Ralph Campbell wrote:
> The goal for this series is to avoid device private memory TLB
> invalidations when migrating a range of addresses from system
> memory to device private memory and some of those pages have already
> been migrated. The approach taken is to introduce a new mmu notifier
> invalidation event type and use that in the device driver to skip
> invalidation callbacks from migrate_vma_setup(). The device driver is
> also then expected to handle device MMU invalidations as part of the
> migrate_vma_setup(), migrate_vma_pages(), migrate_vma_finalize() process.
> Note that this is opt-in. A device driver can simply invalidate its MMU
> in the mmu notifier callback and not handle MMU invalidations in the
> migration sequence.
> 
> This series is based on Jason Gunthorpe's HMM tree (linux-5.8.0-rc4).
> 
> Also, this replaces the need for the following two patches I sent:
> ("mm: fix migrate_vma_setup() src_owner and normal pages")
> https://lore.kernel.org/linux-mm/20200622222008.9971-1-rcampbell@xxxxxxxxxx
> ("nouveau: fix mixed normal and device private page migration")
> https://lore.kernel.org/lkml/20200622233854.10889-3-rcampbell@xxxxxxxxxx
> 
> Changes in v2:
> Rebase to Jason Gunthorpe's HMM tree.
> Added reviewed-by from Bharata B Rao.
> Rename the mmu_notifier_range::data field to migrate_pgmap_owner as
>   suggested by Jason Gunthorpe.

I didn't see anything stand out in this at this point, did you intend
this to go to the HMM tree?

Thanks,
Jason