On 15.11.25 01:28, Balbir Singh wrote:
Follow the pattern used in remove_migration_pte() in
remove_migration_pmd(). Process the migration entries and if the entry
type is device private, override the pmde with a device private entry
and set the soft dirty and uffd_wp bits with the pmd_swp_mksoft_dirty
and pmd_swp_mkuffd_wp
Cc: Andrew Morton <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Zi Yan <[email protected]>
Cc: Joshua Hahn <[email protected]>
Cc: Rakie Kim <[email protected]>
Cc: Byungchul Park <[email protected]>
Cc: Gregory Price <[email protected]>
Cc: Ying Huang <[email protected]>
Cc: Alistair Popple <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Lorenzo Stoakes <[email protected]>
Cc: Baolin Wang <[email protected]>
Cc: "Liam R. Howlett" <[email protected]>
Cc: Nico Pache <[email protected]>
Cc: Ryan Roberts <[email protected]>
Cc: Dev Jain <[email protected]>
Cc: Barry Song <[email protected]>
Cc: Lyude Paul <[email protected]>
Cc: Danilo Krummrich <[email protected]>
Cc: David Airlie <[email protected]>
Cc: Simona Vetter <[email protected]>
Cc: Ralph Campbell <[email protected]>
Cc: Mika Penttilä <[email protected]>
Cc: Matthew Brost <[email protected]>
Cc: Francois Dugast <[email protected]>
Signed-off-by: Balbir Singh <[email protected]>
---
This fixup should be squashed into the patch "mm/rmap: extend rmap and
migration support" of mm/mm-unstable
mm/huge_memory.c | 27 +++++++++++++++++----------
1 file changed, 17 insertions(+), 10 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 9dda8c48daca..50ba458efcab 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -4698,16 +4698,6 @@ void remove_migration_pmd(struct page_vma_mapped_walk
*pvmw, struct page *new)
folio_get(folio);
pmde = folio_mk_pmd(folio, READ_ONCE(vma->vm_page_prot));
- if (folio_is_device_private(folio)) {
- if (pmd_write(pmde))
- entry = make_writable_device_private_entry(
- page_to_pfn(new));
- else
- entry = make_readable_device_private_entry(
- page_to_pfn(new));
- pmde = swp_entry_to_pmd(entry);
- }
-
if (pmd_swp_soft_dirty(*pvmw->pmd))
pmde = pmd_mksoft_dirty(pmde);
if (is_writable_migration_entry(entry))
@@ -4720,6 +4710,23 @@ void remove_migration_pmd(struct page_vma_mapped_walk
*pvmw, struct page *new)
if (folio_test_dirty(folio) && is_migration_entry_dirty(entry))
pmde = pmd_mkdirty(pmde);
+ if (folio_is_device_private(folio)) {
+ swp_entry_t entry;
It's a bit nasty to have the same variable shadowed here.
We could reuse the existing entry by handling the code more similar to
remove_migration_pte(): determine RMAP_EXCLUSIVE earlier.
+
+ if (pmd_write(pmde))
+ entry = make_writable_device_private_entry(
+ page_to_pfn(new));
+ else
+ entry = make_readable_device_private_entry(
+ page_to_pfn(new));
+ pmde = swp_entry_to_pmd(entry);
+
+ if (pmd_swp_soft_dirty(*pvmw->pmd))
+ pmde = pmd_swp_mksoft_dirty(pmde);
+ if (pmd_swp_uffd_wp(*pvmw->pmd))
+ pmde = pmd_swp_mkuffd_wp(pmde);
+ }
+
if (folio_test_anon(folio)) {
rmap_t rmap_flags = RMAP_NONE;
I guess at some point we could separate both parts completely (no need
to do all this work on pmdb before the folio_is_device_private(folio)
check, so this could be
if (folio_is_device_private(folio)) {
...
} else {
entry = pmd_to_swp_entry(*pvmw->pmd);
folio_get(folio);
...
}
That is something for another day though, and remove_migration_pte()
should be cleaned up then as well.
--
Cheers
David
