diff options
| author | Cyrill Gorcunov <gorcunov@gmail.com> | 2013-10-16 13:46:51 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-11-04 04:35:20 -0800 |
| commit | 72d2ddf5f2218861f41b7d1a9da4c130d6d81911 (patch) | |
| tree | 7e92030ef3dcdfa94eddfcd74370a4ae251f39b1 /mm | |
| parent | c0329006f4b3c7ab4dde75aa003de50982a44b91 (diff) | |
mm: migration: do not lose soft dirty bit if page is in migration state
commit c3d16e16522fe3fe8759735850a0676da18f4b1d upstream.
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 <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memory.c | 2 | ||||
| -rw-r--r-- | mm/migrate.c | 2 | ||||
| -rw-r--r-- | mm/mprotect.c | 7 |
3 files changed, 9 insertions, 2 deletions
diff --git a/mm/memory.c b/mm/memory.c index af84bc0ec17c..440986e57218 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -861,6 +861,8 @@ copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm, */ make_migration_entry_read(&entry); pte = swp_entry_to_pte(entry); + if (pte_swp_soft_dirty(*src_pte)) + pte = pte_swp_mksoft_dirty(pte); set_pte_at(src_mm, addr, src_pte, pte); } } diff --git a/mm/migrate.c b/mm/migrate.c index 25ca7caf9092..81af4e678101 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -157,6 +157,8 @@ 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 diff --git a/mm/mprotect.c b/mm/mprotect.c index 94722a4d6b43..a3af058f68e4 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -94,13 +94,16 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, swp_entry_t entry = pte_to_swp_entry(oldpte); if (is_write_migration_entry(entry)) { + pte_t newpte; /* * A protection check is difficult so * just be safe and disable write */ make_migration_entry_read(&entry); - set_pte_at(mm, addr, pte, - swp_entry_to_pte(entry)); + newpte = swp_entry_to_pte(entry); + if (pte_swp_soft_dirty(oldpte)) + newpte = pte_swp_mksoft_dirty(newpte); + set_pte_at(mm, addr, pte, newpte); } pages++; } |