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

[Parav Pandit <pandit.parav@gmail.com>]

Hi Doug,

Leon has finished review as well in [7].
Christoph Acked too in [8].

Can you please advise whether
(1) I should rebase and resend PatchV12?
(2) If so for which branch - master/4.9 or?

Tejun and Christoph mentioned that it might be late for 4.9.
Can we atleast merge to linux-rdma tree, so that more features/changes
can be done on top of it?

How can we avoid merge conflict to Linus since this patchset is
applicable to two git trees. (cgroup and linux-rdma).
I was thinking to push through linux-rdma as it is currently going
through more changes, so resolving merge conflict would be simpler if
that happens.

Please provide the direction.

[7] https://lkml.org/lkml/2016/10/5/134
[8] https://lkml.org/lkml/2016/10/5/30

Regards,
Parav Pandit

On Tue, Oct 4, 2016 at 11:49 PM, Parav Pandit <pandit.parav@gmail.com> wrote:
> 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
> Christoph.
>
> 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?
>
> [1] https://lkml.org/lkml/2016/8/31/494
> [2] https://lkml.org/lkml/2016/8/25/146
> [3] https://lkml.org/lkml/2016/9/10/175
> [4] https://lkml.org/lkml/2016/9/14/221
> [5] https://lkml.org/lkml/2016/9/19/571
> [6] http://www.spinics.net/lists/linux-rdma/msg40337.html
> [7] email subject: [RFC ABI V4 0/7] SG-based RDMA ABI Proposal
>
> Regards,
> Parav Pandit
>
> On Wed, Sep 21, 2016 at 9:32 PM, Parav Pandit <pandit.parav@gmail.com> wrote:
>> Hi Tejun,
>>
>> On Wed, Sep 21, 2016 at 7:56 PM, Tejun Heo <tj@kernel.org> 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] https://www.spinics.net/lists/linux-rdma/msg40340.html
>> [2] http://www.spinics.net/lists/linux-rdma/msg40717.html
>>
>> 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.