On Sun, Jan 19, 2020 at 02:57:53PM +0800, Wei Yang wrote:
>If we get here after successfully adding page to list, err would be
>1 to indicate the page is queued in the list.
>
>Current code has two problems:
>
> * on success, 0 is not returned
> * on error, if add_page_for_migratioin() return 1, and the following err1
> from do_move_pages_to_node() is set, the err1 is not returned since err
> is 1
>
>And these behaviors break the user interface.
>
>Fixes: e0153fc2c760 ("mm: move_pages: return valid node id in status if the
>page is already on the target node").
>Signed-off-by: Wei Yang <richardw.yang@xxxxxxxxxxxxxxx>
>
>---
>v2:
> * put more words to explain the error case
>---
> mm/migrate.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
>diff --git a/mm/migrate.c b/mm/migrate.c
>index 86873b6f38a7..430fdccc733e 100644
>--- a/mm/migrate.c
>+++ b/mm/migrate.c
>@@ -1676,7 +1676,7 @@ static int do_pages_move(struct mm_struct *mm, nodemask_t task_nodes,
> err1 = do_move_pages_to_node(mm, &pagelist, current_node);
> if (!err1)
> err1 = store_status(status, start, current_node, i - start);
>- if (!err)
>+ if (err >= 0)
> err = err1;
Ok, as mentioned by Yang and Michal, only err == 0 means no error.
Sounds this regression should be fixed in another place. Let me send out
another patch.
> out:
> return err;
>--
>2.17.1
--
Wei Yang
Help you, Help me
