The patch titled
Subject: mm: mark stable page dirty in KSM
has been removed from the -mm tree. Its filename was
mm-mark-stable-page-dirty-in-ksm.patch
This patch was dropped because an updated version will be merged
------------------------------------------------------
From: Minchan Kim <minchan@xxxxxxxxxx>
Subject: mm: mark stable page dirty in KSM
Stable page could be shared by several processes and last process could
own the page among them after CoW or zapping for every process except last
process happens. Then, page table entry of the page in last process can
have no dirty bit and PG_dirty flag in page->flags. In this case,
MADV_FREE could discard the page wrongly. For preventing it, we mark
stable page dirty.
Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/ksm.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff -puN mm/ksm.c~mm-mark-stable-page-dirty-in-ksm mm/ksm.c
--- a/mm/ksm.c~mm-mark-stable-page-dirty-in-ksm
+++ a/mm/ksm.c
@@ -1050,6 +1050,18 @@ static int try_to_merge_one_page(struct
*/
set_page_stable_node(page, NULL);
mark_page_accessed(page);
+ /*
+ * Stable page could be shared by several processes
+ * and last process could own the page among them after
+ * CoW or zapping for every process except last process
+ * happens. Then, page table entry of the page
+ * in last process can have no dirty bit.
+ * In this case, MADV_FREE could discard the page
+ * wrongly.
+ * For preventing it, we mark stable page dirty.
+ */
+ if (!PageDirty(page))
+ SetPageDirty(page);
err = 0;
} else if (pages_identical(page, kpage))
err = replace_page(vma, page, kpage, orig_pte);
_
Patches currently in -mm which might be from minchan@xxxxxxxxxx are
x86-add-pmd_-for-thp.patch
sparc-add-pmd_-for-thp.patch
powerpc-add-pmd_-for-thp.patch
arm-add-pmd_mkclean-for-thp.patch
arm64-add-pmd_-for-thp.patch
mm-dont-split-thp-page-when-syscall-is-called.patch
mm-free-swp_entry-in-madvise_free.patch
mm-move-lazy-free-pages-to-inactive-list.patch
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