Date: Tue, 5 Apr 2016 18:44:23 +0300
From: Leon Romanovsky <leon@leon.nu>
To: Parav Pandit <pandit.parav@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>, 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
Subject: Re: [PATCHv10 1/3] rdmacg: Added rdma cgroup controller
Message-ID: <20160405154423.GK5264@leon.nu>
Reply-To: leon@leon.nu
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On Tue, Apr 05, 2016 at 05:55:26AM -0700, Parav Pandit wrote:
> Hi Christoph,
> 
> On Tue, Apr 5, 2016 at 5:42 AM, Christoph Hellwig <hch@infradead.org> wrote:
> > On Tue, Apr 05, 2016 at 05:39:21AM -0700, Parav Pandit wrote:
> >> 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.
> >
> > What a load of rubbish.  The Linux kernel is one program and should be
> > upgraded together.
> 
> Just because we add one more rdma resource, we need to ask someone to
> upgrade kernel?

It doesn't make sense. Kernel and modules are always coming together,
the attempts to mix kernel and modules from different versions can lead
to many interesting debug scenarios.