Re: [PATCH 1/2] Check PageUnevictable in lru_deactivate_fn

Ying Han
2011-05-01T22:11:07Z

On Sun, May 1, 2011 at 8:03 AM, Minchan Kim <minchan.kim@gmail.com> wrote:
> The lru_deactivate_fn should not move page which in on unevictable lru
> into inactive list. Otherwise, we can meet BUG when we use isolate_lru_pages
> as __isolate_lru_page could return -EINVAL.
> It's really BUG and let's fix it.
>
> Reported-by: Ying Han <yinghan@google.com>
> Tested-by: Ying Han <yinghan@google.com>
> Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
> ---
>  mm/swap.c |    3 +++
>  1 files changed, 3 insertions(+), 0 deletions(-)
>
> diff --git a/mm/swap.c b/mm/swap.c
> index a83ec5a..2e9656d 100644
> --- a/mm/swap.c
> +++ b/mm/swap.c
> @@ -429,6 +429,9 @@ static void lru_deactivate_fn(struct page *page, void *arg)
>        if (!PageLRU(page))
>                return;
>
> +       if (PageUnevictable(page))
> +               return;
> +
>        /* Some processes are using the page */
>        if (page_mapped(page))
>                return;
> --
> 1.7.1

Thanks Minchan for the fix, and i haven't been able to reproducing the
issue after applying the patch.

--Ying

>