Re: [RFC] Making memcg track ownership per address_space or anon_vma

Tejun Heo
2015-02-05T22:25:22Z

Hey,

On Thu, Feb 05, 2015 at 02:05:19PM -0800, Greg Thelen wrote:
> > A
> > +-B (usage=2M lim=3M min=2M hosted_usage=2M)
> > +-C (usage=0 lim=2M min=1M shared_usage=2M)
> > +-D (usage=0 lim=2M min=1M shared_usage=2M)
> > \-E (usage=0 lim=2M min=0)
...
> Maybe, but I want to understand more about how pressure works in the
> child. As C (or D) allocates non shared memory does it perform reclaim
> to ensure that its (C.usage + C.shared_usage < C.lim). Given C's

Yes.

> shared_usage is linked into B.LRU it wouldn't be naturally reclaimable
> by C. Are you thinking that charge failures on cgroups with non zero
> shared_usage would, as needed, induce reclaim of parent's hosted_usage?

Hmmm.... I'm not really sure but why not? If we properly account for
the low protection when pushing inodes to the parent, I don't think
it'd break anything. IOW, allow the amount beyond the sum of low
limits to be reclaimed when one of the sharers is under pressure.

Thanks.

--
tejun