Re: CPU Hotplug: Hotplug Script And SIGPWR

[Nick Piggin]

Srivatsa Vaddagiri wrote:

> On Tue, Jan 20, 2004 at 12:43:52AM -0800, Tim Hockin wrote:
>
> > IFF the app is designed to handle it.  The existence of a SIGPWR handler
> > does not necessarily imply that, though.  a SIGCPU or something might
> > correlate 1:1 with this, but SIGPWR doesn't.
>
> I agree we should have a separe signal for CPU Hotplug. By default the signal 
> will be ignored, unless a task registers a signal handler for that special 
> signal.

I'd be happy with that.

> That way, tasks which "knowingly" change their CPU affinity will be able to 
> tackle a CPU going down by handling the signal (probably change their CPU 
> affinity again), while tasks which have their CPU affinity changed "unknowingly"
> (by other tasks) will just ignore the signal. The hotplug script interface
> allows the admin to go and change the CPU affinity again for the second class 
> of tasks, if needed.

Yes, that is with the cpu-is-down hotplug event, right?

*Before* that happens, tasks that don't handle the signal should just
have their affinity changed to all cpus.

Or doesn't anybody care to think about hoplug scripts failing?
(serious question)


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