Re: [RFC][PATCH 1/2] Track in-kernel when we expectcheckpoint/restart to work

From: Greg Kurz
Date: Fri Oct 10 2008 - 04:48:47 EST


On Fri, 2008-10-10 at 10:37 +0200, Daniel Lezcano wrote:
> I think implementing the reverse operation will be a nightmare, IMHO it
> is safe to say we deny checkpointing for the process life-cycle either
> if the created resource was destroyed before we initiate the checkpoint.
>
> For example, you create a socket, the process becomes uncheckpointable,
> you close (via sys_close) the socket, you have to track this close to be
> related to the socket which made the process uncheckpointable in order
> to make the operation reversible.
>
> Let's imagine you implement this reverse operation anyway, you have a
> process which creates a TCP connection, writes data and close the socket
> (so you are again checkpointable), but in the namespace there is the
> orphan socket which is not checkpointable yet and you missed this case.

That's exactly what I wanted to read... Tracking only is inherently
flawed. The valid way IMHO implies checks at checkpoint time.

--
Gregory Kurz gkurz@xxxxxxxxxx
Software Engineer @ IBM/Meiosys http://www.ibm.com
Tel +33 (0)534 638 479 Fax +33 (0)561 400 420

"Anarchy is about taking complete responsibility for yourself."
Alan Moore.

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