From mboxrd@z Thu Jan  1 00:00:00 1970
From: Tejun Heo <tj@kernel.org>
Subject: Re: [Ksummit-2010-discuss] checkpoint-restart: naked patch
Date: Fri, 19 Nov 2010 17:06:14 +0100
Message-ID: <4CE6A076.2020807@kernel.org>
References: <20101104164401.GC10656@sundance.ccs.neu.edu>	<4CD3CE29.2010105@kernel.org>	<20101106053204.GB12449@count0.beaverton.ibm.com>	<20101106204008.GA31077@sundance.ccs.neu.edu>	<4CD5D99A.8000402@cs.columbia.edu>	<20101107184927.GF31077@sundance.ccs.neu.edu>	<4CD72150.9070705@cs.columbia.edu>	<4CE3C334.9080401@kernel.org>	<20101117153902.GA1155@hallyn.com>	<4CE3F8D1.10003@kernel.org>	<20101119041045.GC24031@hallyn.com>	<4CE683E1.6010500@kernel.org>	<04F4899E-B5C7-4BAF-8F2F-05D507A91408@parallels.com>	<4CE698C5.5060806@kernel.org> <AANLkTikRHuaCpaROtty6X_Oe6JixzgcbVsxHxvtsu+UV@mail.gmail.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Return-path: <linux-kernel-owner@vger.kernel.org>
In-Reply-To: <AANLkTikRHuaCpaROtty6X_Oe6JixzgcbVsxHxvtsu+UV@mail.gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
To: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Kirill Korotaev <dev@parallels.com>, Serge Hallyn <serge.hallyn@canonical.com>, Kapil Arya <kapil@ccs.neu.edu>, Gene Cooperman <gene@ccs.neu.edu>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, Pavel Emelianov <xemul@parallels.com>, "Eric W. Biederman" <ebiederm@xmission.com>, Linux Containers <containers@lists.osdl.org>
List-Id: containers.vger.kernel.org

Hello,

On 11/19/2010 05:00 PM, Alexey Dobriyan wrote:
> On Fri, Nov 19, 2010 at 5:33 PM, Tejun Heo <tj@kernel.org> wrote:
>>> - insert SKB's into socket buffers
>>
>> Can't we drain kernel buffers?  ie. Stop further writing and wait the
>> send-q to drop to zero.
> 
> On send:
> if network dies right after freeze, you lose.

Gosh, if you're really worried about that, put a netfilter module
which would buffer and simulate acks to extract the packets before
initiating freeze.  These are fringe problems.  Use fringe solutions.

> On receive:
> packets arrive after process freeze, but before network device freeze.

Just store the data somewhere.  The checkpointer can drain the socket,
right?

>>> - setting different statistics counters (like netdev stats etc.)
>>> and so on...
>>
>> Why would this matter?
> 
> Because you'll introduce million stupid interfaces not interesting to
> anyone but C/R.

In this thread, how many have you guys come up with?  Not even a dozen
and most can be sovled almost trivially.  Seriously, what the hell..

Thanks.

-- 
tejun