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Date: Tue, 5 Apr 2016 05:39:21 -0700
Message-ID: <CAG53R5WBBUj6=B81Q-zEwL_xy3_yXUofJ6p921baqnqeVocDPQ@mail.gmail.com>
Subject: Re: [PATCHv10 1/3] rdmacg: Added rdma cgroup controller
From: Parav Pandit <pandit.parav@gmail.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: Tejun Heo <tj@kernel.org>, cgroups@vger.kernel.org,
        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-rdma@vger.kernel.org, lizefan@huawei.com,
        Johannes Weiner <hannes@cmpxchg.org>,
        Doug Ledford <dledford@redhat.com>, Liran Liss <liranl@mellanox.com>,
        "Hefty, Sean" <sean.hefty@intel.com>,
        Jason Gunthorpe <jgunthorpe@obsidianresearch.com>,
        Haggai Eran <haggaie@mellanox.com>, Jonathan Corbet <corbet@lwn.net>,
        james.l.morris@oracle.com, serge@hallyn.com,
        Or Gerlitz <ogerlitz@mellanox.com>, Matan Barak <matanb@mellanox.com>,
        akpm@linux-foundation.org, linux-security-module@vger.kernel.org
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Hi Christoph,

On Tue, Apr 5, 2016 at 2:06 AM, Christoph Hellwig <hch@infradead.org> wrote:
> On Mon, Apr 04, 2016 at 09:25:04PM -0400, Tejun Heo wrote:
>> Is it actually customary to have rdma core module updated more
>> frequently separate from the kernel?  Out-of-tree modules being
>> updated separately happens quite a bit but this is an in-kernel
>> module, which usually is tightly coupled with the rest of the kernel.
>
> People do it for all the wrong reasons - OFED and organization of morons
> wants people to use their modules, which causes lots of harm.  Anything
> that makes this harder is a good thing.
>
I am not really trying to address OFED issues here. I am sure you
understand that if ib_core.ko kernel module is in-kernel module than,
for all the fixes/enhancements that goes to it would require people to
upgrade to newer kernel, instead of just modules upgrade. Such heavy
weight upgrade slows down the adoption which i am trying to avoid here
by placing knobs in right kernel module's hand.
Its like making ib_core.ko from module to in kernel component, if I
understand correctly nobody wants to do that.