2020-08-31 23:00:12

by Ralph Campbell

Subject: [PATCH 0/2] mm/migrate: preserve soft dirty in remove_migration_pte()

Two small patches for Andrew Morton's mm tree.
I happened to notice this from code inspection after seeing Alistair
Popple's patch ("mm/rmap: Fixup copying of soft dirty and uffd ptes").

Ralph Campbell (2):
mm/migrate: remove unnecessary is_zone_device_page() check
mm/migrate: preserve soft dirty in remove_migration_pte()

mm/migrate.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

--
2.20.1

2020-08-31 23:00:19

by Ralph Campbell

Subject: [PATCH 1/2] mm/migrate: remove unnecessary is_zone_device_page() check

The check for is_zone_device_page() and is_device_private_page() is
unnecessary since the latter is sufficient to determine if the page
is a device private page. Simplify the code for easier reading.

Signed-off-by: Ralph Campbell <[email protected]>
---
mm/migrate.c | 12 +++++-------
1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index 659d3d8a3e1f..fe339a847328 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -246,13 +246,11 @@ static bool remove_migration_pte(struct page *page, struct vm_area_struct *vma,
else if (pte_swp_uffd_wp(*pvmw.pte))
pte = pte_mkuffd_wp(pte);

- if (unlikely(is_zone_device_page(new))) {
- if (is_device_private_page(new)) {
- entry = make_device_private_entry(new, pte_write(pte));
- pte = swp_entry_to_pte(entry);
- if (pte_swp_uffd_wp(*pvmw.pte))
- pte = pte_swp_mkuffd_wp(pte);
- }
+ if (unlikely(is_device_private_page(new))) {
+ entry = make_device_private_entry(new, pte_write(pte));
+ pte = swp_entry_to_pte(entry);
+ if (pte_swp_uffd_wp(*pvmw.pte))
+ pte = pte_swp_mkuffd_wp(pte);
}

#ifdef CONFIG_HUGETLB_PAGE
--
2.20.1

2020-09-01 05:21:10

by Christoph Hellwig

Subject: Re: [PATCH 1/2] mm/migrate: remove unnecessary is_zone_device_page() check

Looks good:

Reviewed-by: Christoph Hellwig <[email protected]>