diff options
| author | Ralph Campbell <rcampbell@nvidia.com> | 2020-07-23 15:30:01 -0700 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@nvidia.com> | 2020-07-28 16:20:33 -0300 |
| commit | 998427b3ad2c769082853880cf353557ec0ec77d (patch) | |
| tree | 05381a8bcb45c98431dff8f52d70d1cf87648ec9 /include/linux/migrate.h | |
| parent | 5143192cd410c4fc83be09a2e73423765aee072b (diff) | |
| download | linux-998427b3ad2c769082853880cf353557ec0ec77d.tar.bz2 | |
mm/notifier: add migration invalidation type
Currently migrate_vma_setup() calls mmu_notifier_invalidate_range_start()
which flushes all device private page mappings whether or not a page is
being migrated to/from device private memory.
In order to not disrupt device mappings that are not being migrated, shift
the responsibility for clearing device private mappings to the device
driver and leave CPU page table unmapping handled by
migrate_vma_setup().
To support this, the caller of migrate_vma_setup() should always set
struct migrate_vma::pgmap_owner to a non NULL value that matches the
device private page->pgmap->owner. This value is then passed to the struct
mmu_notifier_range with a new event type which the driver's invalidation
function can use to avoid device MMU invalidations.
Link: https://lore.kernel.org/r/20200723223004.9586-4-rcampbell@nvidia.com
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Diffstat (limited to 'include/linux/migrate.h')
| -rw-r--r-- | include/linux/migrate.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/migrate.h b/include/linux/migrate.h index 16e03a51e5cf..540998d9810b 100644 --- a/include/linux/migrate.h +++ b/include/linux/migrate.h @@ -206,6 +206,9 @@ struct migrate_vma { * Set to the owner value also stored in page->pgmap->owner for * migrating out of device private memory. The flags also need to * be set to MIGRATE_VMA_SELECT_DEVICE_PRIVATE. + * The caller should always set this field when using mmu notifier + * callbacks to avoid device MMU invalidations for device private + * pages that are not being migrated. */ void *pgmap_owner; unsigned long flags; |