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

Minchan Kim
2011-05-01T23:00:48Z

On Mon, May 2, 2011 at 7:10 AM, Ying Han <yinghan@google.com> wrote:
> 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.

Thanks for the help, Ying.

--
Kind regards,
Minchan Kim