Re: memcg oops: memcg_kmem_charge_memcg()->try_charge()->page_counter_try_charge()->BOOM

[Mike Galbraith]

On Mon, 2018-10-29 at 18:54 +0000, Roman Gushchin wrote:
> 
> Hi Mike!
> 
> Thank you for the report!
> 
> Do you see it reliable every time you boot up the machine?

Yeah.

> How do you run kvm?

My VMs are full SW/data clones of my i7-4790/openSUSE <release> box.

>  Is there something special about your cgroup setup?

No, I generally have no use for cgroups.

> I've made several attempts to reproduce the issue, but haven't got anything
> so far. I've used your config, and played with different cgroups setups.

Ah, I have cgroup_disable=memory on the command line, which turns out
to be why your box doesn't explode, while mine does.

> Do you know where in the page_counter_try_charge() it fails?
> 
> Also, can you, please, check if the following patch mitigates the problem?

Yeah, that plugs it up.

	-Mike