Re: [PATCHv12 1/3] rdmacg: Added rdma cgroup controller

From: Parav Pandit
Date: Tue Oct 04 2016 - 14:19:14 EST

Hi Doug,

I am still waiting for Leon to provide his comments if any on rdma cgroup.
>From other email context, he was on vacation last week.
While we wait for his comments, I wanted to know your view of this
patchset in 4.9 merge window.

To summarize the discussion that happened in two threads.

[1] Ack by Tejun, asking for review from rdma list
[2] quick review by Christoph on patch-v11 (patch 12 has only typo corrections)
[3] Christoph's ack on architecture of rdma cgroup and fitting it with ABI
[4] My response on Matan's query on RSS indirection table
[5] Response from Intel on their driver support for Matan's query
[6] Christoph's point on architecture, which we are following in new
ABI and current ABI

I have reviewed recent patch [7] from Matan where I see IB verbs
objects are still handled through common path as suggested by

I do not see any issues with rdma cgroup patchset other than it requires rebase.
Am I missing something?
Can you please help me - What would be required to merge it to 4.9?

[7] email subject: [RFC ABI V4 0/7] SG-based RDMA ABI Proposal

Parav Pandit

On Wed, Sep 21, 2016 at 9:32 PM, Parav Pandit <pandit.parav@xxxxxxxxx> wrote:
> Hi Tejun,
> On Wed, Sep 21, 2016 at 7:56 PM, Tejun Heo <tj@xxxxxxxxxx> wrote:
>> Hello, Parav.
>> On Wed, Sep 21, 2016 at 10:13:38AM +0530, Parav Pandit wrote:
>>> We have completed review from Tejun, Christoph.
>>> HFI driver folks also provided feedback for Intel drivers.
>>> Matan's also doesn't have any more comments.
>>> If possible, if you can also review, it will be helpful.
>>> I have some more changes unrelated to cgroup in same files in both the git tree.
>>> Pushing them now either results into merge conflict later on for
>>> Doug/Tejun, or requires rebase and resending patch.
>>> If you can review, we can avoid such rework.
>> My impression of the thread was that there doesn't seem to be enough
>> of consensus around how rdma resources should be defined. Is that
>> part agreed upon now?
> We ended up discussing few points on different thread [1].
> There was confusion on how some non-rdma/non-IB drivers would work
> with rdma cgroup from Matan.
> Christoph explained how they don't fit in the rdma subsystem and
> therefore its not prime target to addess.
> Intel driver maintainer Denny also acknowledged same on [2].
> IB compliant drivers of Intel support rdma cgroup as explained in [2].
> With that usnic and Intel psm drivers falls out of rdma cgroup support
> as they don't fit very well in the verbs definition.
> [1]
> [2]
> I will wait for Leon's review comments if he has different view on architecture.
> Back in April when I met face-to-face to Leon and Haggai, Leon was in
> support to have kernel defined the rdma resources as suggested by
> Christoph and Tejun instead of IB/RDMA subsystem.
> I will wait for his comments if his views have changed with new uAPI
> taking shape.