On 24/04/2017 11:05, Naoya Horiguchi wrote:
> On Thu, Apr 20, 2017 at 11:26:01AM +0200, Laurent Dufour wrote:
>> When page are poisoned, they should be uncharged from the root memory
>> cgroup.
>
> Could you include some information about what problem this patch tries
> to solve?
> # I know that you already explain it in patch 0/2, so you can simply
> # copy from it.
Thanks for the review, I will add the BUG's output in the next version.
>
>>
>> Signed-off-by: Laurent Dufour <lduf...@linux.vnet.ibm.com>
>> ---
>> mm/memory-failure.c | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
>> index 27f7210e7fab..00bd39d3d4cb 100644
>> --- a/mm/memory-failure.c
>> +++ b/mm/memory-failure.c
>> @@ -530,6 +530,7 @@ static const char * const action_page_types[] = {
>> static int delete_from_lru_cache(struct page *p)
>> {
>> if (!isolate_lru_page(p)) {
>> + memcg_kmem_uncharge(p, 0);
>
> This function is supposed to be called with if (memcg_kmem_enabled()) check,
> so could you do like below?
>
> + if (memcg_kmem_enabled())
> + memcg_kmem_uncharge(p, 0);
>
>
> And I feel that we can call this function outside if (!isolate_lru_page(p))
> block, because isolate_lru_page could fail and then the error page is left
> incompletely isolated. Such error page has PageHWPoison set, so I guess that
> the reported bug still triggers on such case.
I move the call to memcg_kmem_uncharge() outside if
(!isolate_lru_page(p)) and it seems to work as well.
I'll wait a bit for any other review to come and I'll send a new version.
Thanks,
Laurent.
