mm: migration: do not lose soft dirty bit if page is in migration state

If page migration is turned on in config and the page is migrating, we
may lose the soft dirty bit.  If fork and mprotect are called on
migrating pages (once migration is complete) pages do not obtain the
soft dirty bit in the correspond pte entries.  Fix it adding an
appropriate test on swap entries.

Signed-off-by: Cyrill Gorcunov <[email protected]>
Cc: Pavel Emelyanov <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Matt Mackall <[email protected]>
Cc: Xiao Guangrong <[email protected]>
Cc: Marcelo Tosatti <[email protected]>
Cc: KOSAKI Motohiro <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: "Aneesh Kumar K.V" <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Cyrill Gorcunov 2013-10-16 13:46:51 -07:00 • committed by Linus Torvalds
commit c3d16e1652
3 changed files with 9 additions and 2 deletions

View file

@ -161,6 +161,8 @@ static int remove_migration_pte(struct page *new, struct vm_area_struct *vma,
get_page(new);
pte = pte_mkold(mk_pte(new, vma->vm_page_prot));
if (pte_swp_soft_dirty(*ptep))
pte = pte_mksoft_dirty(pte);
if (is_write_migration_entry(entry))
pte = pte_mkwrite(pte);
#ifdef CONFIG_HUGETLB_PAGE