On 11/17/25 23:58, David Hildenbrand (Red Hat) wrote: > 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. >
Agreed and Thanks for the review! Balbir
