Re: [RFC v7][PATCH 0/9] Kernel based checkpoint/restart

[Ingo Molnar <mingo@elte.hu>]

* Dave Hansen <dave@linux.vnet.ibm.com> wrote:

> On Tue, 2008-10-21 at 12:21 -0700, Andrew Morton wrote:
> > On Mon, 20 Oct 2008 01:40:28 -0400
> > Oren Laadan <orenl@cs.columbia.edu> wrote:
> > > These patches implement basic checkpoint-restart [CR]. This version
> > > (v7) supports basic tasks with simple private memory, and open files
> > > (regular files and directories only).
> > 
> > - how useful is this code as it stands in real-world usage?
> 
> Right now, an application must be specifically written to use these 
> mew system calls.  It must be a single process and not share any 
> resources with other processes.  The only file descriptors that may be 
> open are simple files and may not include sockets or pipes.
> 
> What this means in practice is that it is useful for a simple app 
> doing computational work.

say a chemistry application doing calculations. Or a raytracer with a 
large job. Both can take many hours (days!) even on very fast machine 
and the restrictions on rebootability can hurt in such cases.

You should reach a minimal level of initial practical utility: say some 
helper tool that allows testers to checkpoint and restore a real PovRay 
session - without any modification to a stock distro PovRay.

	Ingo