Re: [Bug 201699] New: kmemleak in memcg_create_kmem_cache

[段熊春 <duanxiongchun@xxxxxxxxxxxxx>]

hi all：

In same case， I think it’s may be a problem。

if I create a virtual netdev device under mem cgroup(like ip link add ve_A type veth peer name ve_B).after that ,I destroy this mem cgroup。

I find that may the object  net_device, will be hold by the kernel until I run command (ip link del ). And the memory pages which container the object won’t be uncharge. mem_cgroup object  also will be not free. 

Anothers may think kernel just hold sizeof(struct netdev_device) memory size. But,it’s not really,it’s much bigger than they think.

It’s maybe a problems, I am not very sure about that.

 Thanks

bytedance.net
段熊春
duanxiongchun@xxxxxxxxxxxxx

On Nov 21, 2018, at 5:22 PM, dong <bauers@xxxxxxx> wrote:

Thanks for replying, Michal.

cc to duanxiongchun

At 2018-11-21 17:10:41, "Michal Hocko" <mhocko@xxxxxxxxxx> wrote:
>On Wed 21-11-18 16:46:48, dong wrote:
>> The last question: If I alloc many small pages and not free them, will
>> I exhaust the memory ( because every page contains `mem_cgroup` )?
>
>No, the memory will get reclaimed on the memory pressure or for
>anonymous one (malloc) when the process allocating it terminates,
>-- 
>Michal Hocko
>SUSE Labs