[v2,0/5] mm/migrate: avoid device private invalidations
mbox series

Message ID 20200713172149.2310-1-rcampbell@nvidia.com
Headers show
Series
  • mm/migrate: avoid device private invalidations
Related show

Message

Ralph Campbell July 13, 2020, 5:21 p.m. UTC
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@nvidia.com
("nouveau: fix mixed normal and device private page migration")
https://lore.kernel.org/lkml/20200622233854.10889-3-rcampbell@nvidia.com

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.

Ralph Campbell (5):
  nouveau: fix storing invalid ptes
  mm/migrate: add a direction parameter to migrate_vma
  mm/notifier: add migration invalidation type
  nouveau/svm: use the new migration invalidation
  mm/hmm/test: use the new migration invalidation

 arch/powerpc/kvm/book3s_hv_uvmem.c            |  2 ++
 drivers/gpu/drm/nouveau/nouveau_dmem.c        | 13 ++++++--
 drivers/gpu/drm/nouveau/nouveau_svm.c         | 10 +++++-
 drivers/gpu/drm/nouveau/nouveau_svm.h         |  1 +
 .../drm/nouveau/nvkm/subdev/mmu/vmmgp100.c    | 13 +++++---
 include/linux/migrate.h                       | 12 +++++--
 include/linux/mmu_notifier.h                  |  7 ++++
 lib/test_hmm.c                                | 33 +++++++++++--------
 mm/migrate.c                                  | 13 ++++++--
 9 files changed, 77 insertions(+), 27 deletions(-)

Comments

Jason Gunthorpe July 20, 2020, 6:41 p.m. UTC | #1
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@nvidia.com
> ("nouveau: fix mixed normal and device private page migration")
> https://lore.kernel.org/lkml/20200622233854.10889-3-rcampbell@nvidia.com
> 
> 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
Ralph Campbell July 20, 2020, 7:58 p.m. UTC | #2
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@nvidia.com
>> ("nouveau: fix mixed normal and device private page migration")
>> https://lore.kernel.org/lkml/20200622233854.10889-3-rcampbell@nvidia.com
>>
>> 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.