Currently, migration code increases num_poisoned_pages on failed
migration page as well as successfully migrated one at the trial
of memory-failure. It will make the stat wrong.
As well, it marks page as PG_HWPoison even if the migration trial
failed. It would make we cannot recover the corrupted page using
memory-failure facility.
This patches fixes it.
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Vlastimil Babka <vbabka@xxxxxxx>
Acked-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx>
---
mm/migrate.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/mm/migrate.c b/mm/migrate.c
index 6c822a7b27e0..f9dfb18a4eba 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -975,7 +975,13 @@ static ICE_noinline int unmap_and_move(new_page_t get_new_page,
dec_zone_page_state(page, NR_ISOLATED_ANON +
page_is_file_cache(page));
/* Soft-offlined page shouldn't go through lru cache list */
- if (reason == MR_MEMORY_FAILURE) {
+ if (reason == MR_MEMORY_FAILURE && rc == MIGRATEPAGE_SUCCESS) {
+ /*
+ * With this release, we free successfully migrated
+ * page and set PG_HWPoison on just freed page
+ * intentionally. Although it's rather weird, it's how
+ * HWPoison flag works at the moment.
+ */
put_page(page);
if (!test_set_page_hwpoison(page))
num_poisoned_pages_inc();
--
1.9.1
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