Re: [PATCH] stop on cpu lost

[Hugh Dickins <hugh@veritas.com>]

On Thu, 22 Jun 2006, Pavel Machek wrote:
> 
> > > Hm..
> > > Then, there is several ways to manage this sitation.
> > > 
> > > 1. migrate all even if it's not allowed by users
> 
> That's what I'd prefer... as swsusp uses cpu hotplug. All the other
> options are bad... admin will probably not realize suspend involves
> cpu unplugs..
> 
> > > 2. kill mis-configured tasks.
> > > 3. stop ...
> > > 4. cancel cpu-hot-removal.

I'm very reluctant to expose my ignorance by joining this thread;
but what I'd naively expect would, I think, suit swsusp also -
you don't really want tasks to be migrated when resuming?

I'd expect tasks bound to the unplugged cpu simply not to be run
until "that" cpu is plugged back in.

With proviso that it should be possible to "kill -9" such a task
i.e. it be allowed to run in kernel on a wrong cpu just to exit.

Presumably this is difficult, because unplugging a cpu will also
remove infrastructure which would, for example, allow "ps" to show
such tasks.  Perhaps such infrastructure should remain so long as
there are tasks there.

Ignore me if I'm talking nonsense.

Hugh