Re: [RFC PATCH 6/9] livepatch: create per-task consistency model

Jiri Kosina
2015-02-12T12:42:05Z

On Thu, 12 Feb 2015, Peter Zijlstra wrote:

> > Well, the fact indisputable fact is that there is a demand for this. It's
> > not about one machine, it's about scheduling dowtimes of datacentres.
>
> The changelog says:
>
> > ... A patch can remain in the
> > transition state indefinitely, if any of the tasks are stuck in the
> > previous universe.
>
> Therefore there is no scheduling anything. Without timeliness guarantees
> you can't make a schedule.
>
> Might as well just reboot, at least that's fairly well guaranteed to
> happen.

All running (reasonably alive) tasks will be running patched code though.

You can't just claim complete victory (and get ready for accepting another
patch, etc) if there is a long-time sleeper that hasn't been converted
yet.

--
Jiri Kosina
SUSE Labs