Re: [PATCHv1 3/6] rdmacg: implements rdma cgroup

Tejun Heo
2016-01-07T20:28:25Z

Hello, Parav.

On Fri, Jan 08, 2016 at 01:55:09AM +0530, Parav Pandit wrote:
...
> Above functionality is achieved, by maintaining the map this tgid and
> associated original cgroup at try_charge(), uncharge() time.

Hmmm, what happens after the following?

1. A process allocates some rdma resources and get registered on the
hash table.

2. The process gets migrated to a different cgroup.

3. The process allocates more rdma resources.

Which cgroup would the resources from #3 be attributed to?

> In alternate method,
> Its simple to store the pointer of rdma_cgroup structure in the IB
> resource structure and hold on reference count to rdma_cgroup.
> so that when its freed, uncharge_resource can accept rdma_cgroup
> structure pointer.

That'd be a lot more in line with how other controllers behave.

Thanks.

--
tejun