Re: [PATCH 6/6] mm/page_owner: use stackdepot to store stacktrace

[Joonsoo Kim]

2016-05-04 18:23 GMT+09:00 Michal Hocko <mhocko@xxxxxxxxxx>:
> On Wed 04-05-16 11:35:00, Joonsoo Kim wrote:
> [...]
>> Oops... I think more deeply and change my mind. In recursion case,
>> stack is consumed more than 1KB and it would be a problem. I think
>> that best approach is using preallocated per cpu entry. It will also
>> close recursion detection issue by paying interrupt on/off overhead.
>
> I was thinking about per-cpu solution as well but the thing is that the
> stackdepot will allocate and until you drop __GFP_DIRECT_RECLAIM then
> per-cpu is not safe. I haven't checked the implamentation of
> depot_save_stack but I assume it will not schedule in other places.

I will think more.

Thanks for review!

Thanks.