mm: save soft-dirty bits on swapped pages

[~andy/linux] / mm / rmap.c

diff --git a/mm/rmap.c b/mm/rmap.c
index cd356df4f71ab5aa0514e7685b4cce50eafceb6e..83325b80142b7c9a862cd0d56cf1e4c36be04864 100644 (file)
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1236,6 +1236,7 @@ int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
                           swp_entry_to_pte(make_hwpoison_entry(page)));
        } else if (PageAnon(page)) {
                swp_entry_t entry = { .val = page_private(page) };
+               pte_t swp_pte;
 
                if (PageSwapCache(page)) {
                        /*
@@ -1264,7 +1265,10 @@ int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
                        BUG_ON(TTU_ACTION(flags) != TTU_MIGRATION);
                        entry = make_migration_entry(page, pte_write(pteval));
                }
-               set_pte_at(mm, address, pte, swp_entry_to_pte(entry));
+               swp_pte = swp_entry_to_pte(entry);
+               if (pte_soft_dirty(pteval))
+                       swp_pte = pte_swp_mksoft_dirty(swp_pte);
+               set_pte_at(mm, address, pte, swp_pte);
                BUG_ON(pte_file(*pte));
        } else if (IS_ENABLED(CONFIG_MIGRATION) &&
                   (TTU_ACTION(flags) == TTU_MIGRATION)) {