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

From: Parav Pandit
Date: Tue Oct 18 2016 - 16:15:55 EST

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.


Parav Pandit

On Tue, Oct 4, 2016 at 11:49 PM, Parav Pandit <pandit.parav@xxxxxxxxx> 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]
> [2]
> [3]
> [4]
> [5]
> [6]
> [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@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.