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| author | Alistair Popple <apopple@nvidia.com> | 2022-11-11 11:51:35 +1100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2022-11-22 18:50:43 -0800 |
| commit | 44af0b45d58d7b6f09ebb9081aa89b8bdc33a630 (patch) | |
| tree | eacade4974dd134b4dc4d02490ea742d71bde44e /mm/migrate_device.c | |
| parent | 50c697215a8cc22f0e58c88f06f2716c05a26e85 (diff) | |
| download | linux-44af0b45d58d7b6f09ebb9081aa89b8bdc33a630.tar.gz linux-44af0b45d58d7b6f09ebb9081aa89b8bdc33a630.tar.bz2 linux-44af0b45d58d7b6f09ebb9081aa89b8bdc33a630.zip | |
mm/migrate_device: return number of migrating pages in args->cpages
migrate_vma->cpages originally contained a count of the number of pages
migrating including non-present pages which can be populated directly on
the target.
Commit 241f68859656 ("mm/migrate_device.c: refactor migrate_vma and
migrate_device_coherent_page()") inadvertantly changed this to contain
just the number of pages that were unmapped. Usage of migrate_vma->cpages
isn't documented, but most drivers use it to see if all the requested
addresses can be migrated so restore the original behaviour.
Link: https://lkml.kernel.org/r/20221111005135.1344004-1-apopple@nvidia.com
Fixes: 241f68859656 ("mm/migrate_device.c: refactor migrate_vma and migrate_deivce_coherent_page()")
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Reported-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Alex Sierra <alex.sierra@amd.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/migrate_device.c')
| -rw-r--r-- | mm/migrate_device.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/mm/migrate_device.c b/mm/migrate_device.c index 6fa682eef7a0..721b2365dbca 100644 --- a/mm/migrate_device.c +++ b/mm/migrate_device.c @@ -357,7 +357,8 @@ static bool migrate_vma_check_page(struct page *page, struct page *fault_page) } /* - * Unmaps pages for migration. Returns number of unmapped pages. + * Unmaps pages for migration. Returns number of source pfns marked as + * migrating. */ static unsigned long migrate_device_unmap(unsigned long *src_pfns, unsigned long npages, @@ -373,8 +374,11 @@ static unsigned long migrate_device_unmap(unsigned long *src_pfns, struct page *page = migrate_pfn_to_page(src_pfns[i]); struct folio *folio; - if (!page) + if (!page) { + if (src_pfns[i] & MIGRATE_PFN_MIGRATE) + unmapped++; continue; + } /* ZONE_DEVICE pages are not on LRU */ if (!is_zone_device_page(page)) { |