Re: [Ksummit-2010-discuss] checkpoint-restart: naked patch

From: Tejun Heo
Date: Fri Nov 19 2010 - 11:06:46 EST


Hello,

On 11/19/2010 05:00 PM, Alexey Dobriyan wrote:
> On Fri, Nov 19, 2010 at 5:33 PM, Tejun Heo <tj@xxxxxxxxxx> 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
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