diff options
| author | Cyrill Gorcunov <gorcunov@openvz.org> | 2014-06-04 16:06:41 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-06-04 16:53:56 -0700 |
| commit | 0bf073315cb29d2e9e68b6c5da97862a519e3320 (patch) | |
| tree | b9ebb344d324b13211d3e9f1784d13684a420117 /mm/fremap.c | |
| parent | 52383431b37cdbec63944e953ffc2698a7ad9722 (diff) | |
| download | lwn-0bf073315cb29d2e9e68b6c5da97862a519e3320.tar.gz lwn-0bf073315cb29d2e9e68b6c5da97862a519e3320.zip | |
mm: softdirty: make freshly remapped file pages being softdirty unconditionally
Hugh reported:
| I noticed your soft_dirty work in install_file_pte(): which looked
| good at first, until I realized that it's propagating the soft_dirty
| of a pte it's about to zap completely, to the unrelated entry it's
| about to insert in its place. Which seems very odd to me.
Indeed this code ends up being nop in result -- pte_file_mksoft_dirty()
operates with pte_t argument and returns new pte_t which were never used
after. After looking more I think what we need is to soft-dirtify all
newely remapped file pages because it should look like a new mapping for
memory tracker.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Reported-by: Hugh Dickins <hughd@google.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/fremap.c')
| -rw-r--r-- | mm/fremap.c | 7 |
1 files changed, 2 insertions, 5 deletions
diff --git a/mm/fremap.c b/mm/fremap.c index 34feba60a17e..2c5646f11f41 100644 --- a/mm/fremap.c +++ b/mm/fremap.c @@ -82,13 +82,10 @@ static int install_file_pte(struct mm_struct *mm, struct vm_area_struct *vma, ptfile = pgoff_to_pte(pgoff); - if (!pte_none(*pte)) { - if (pte_present(*pte) && pte_soft_dirty(*pte)) - pte_file_mksoft_dirty(ptfile); + if (!pte_none(*pte)) zap_pte(mm, vma, addr, pte); - } - set_pte_at(mm, addr, pte, ptfile); + set_pte_at(mm, addr, pte, pte_file_mksoft_dirty(ptfile)); /* * We don't need to run update_mmu_cache() here because the "file pte" * being installed by install_file_pte() is not a real pte - it's a |