diff mbox series

[v4] mm/migrate_device: Try to handle swapcache pages

Message ID 20230607172944.11713-1-mpenttil@redhat.com
State New
Headers
Series [v4] mm/migrate_device: Try to handle swapcache pages |

Commit Message

Mika Penttilä June 7, 2023, 5:29 p.m. UTC 
  From: Mika Penttilä <mpenttil@redhat.com>

Migrating file pages and swapcache pages into device memory is not supported.
Try to get rid of the swap cache, and if successful, go ahead as
with other anonymous pages.

Cc: Alistair Popple <apopple@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Signed-off-by: Mika Penttilä <mpenttil@redhat.com>
---

v4:
  - fix commit log message
  - delete empty line

v3:
  - adjust comments
  - add Reviewed-bys

v2:
  - use folio_test_anon() (Huang, Ying)

 mm/migrate_device.c | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)
diff mbox series

Patch

diff --git a/mm/migrate_device.c b/mm/migrate_device.c
index d30c9de60b0d..56411b063231 100644
--- a/mm/migrate_device.c
+++ b/mm/migrate_device.c
@@ -747,13 +747,22 @@  static void __migrate_device_pages(unsigned long *src_pfns,
 
 		if (is_device_private_page(newpage) ||
 		    is_device_coherent_page(newpage)) {
-			/*
-			 * For now only support anonymous memory migrating to
-			 * device private or coherent memory.
-			 */
 			if (mapping) {
-				src_pfns[i] &= ~MIGRATE_PFN_MIGRATE;
-				continue;
+				struct folio *folio;
+
+				folio = page_folio(page);
+
+				/*
+				 * For now only support anonymous memory migrating to
+				 * device private or coherent memory.
+				 *
+				 * Try to get rid of swap cache if possible.
+				 */
+				if (!folio_test_anon(folio) ||
+				    !folio_free_swap(folio)) {
+					src_pfns[i] &= ~MIGRATE_PFN_MIGRATE;
+					continue;
+				}
 			}
 		} else if (is_zone_device_page(newpage)) {
 			/*