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.
Reported-by: Hugh Dickins <hughd@xxxxxxxxxx>
CC: Pavel Emelyanov <xemul@xxxxxxxxxxxxx>
CC: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Cyrill Gorcunov <gorcunov@xxxxxxxxxx>
---
mm/fremap.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)
Index: linux-2.6.git/mm/fremap.c
===================================================================
--- linux-2.6.git.orig/mm/fremap.c
+++ linux-2.6.git/mm/fremap.c
@@ -66,13 +66,10 @@ static int install_file_pte(struct mm_st
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
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>