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

[Ralph Campbell]

On 7/20/20 11:41 AM, Jason Gunthorpe wrote:
> 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

Yes, please.