Re: [PATCH 3/4] 2.6.2-rc2-mm2 CPU Hotplug: The Core

From: Rusty Russell
Date: Tue Feb 03 2004 - 20:43:50 EST


In message <Pine.LNX.4.58.0402030418310.22596@xxxxxxxxxxxxxxxxxxxxxxxx> you write:
> > introduce a SIGRECONF (default ignored). But AFAICT, introducing a new
> > signal isn't possible (at least on x86) without breaking glibc.
>
> you can introduce a variable RT signal for this purpose no problem - and
> one would want to have a queued signal for this anyway. Ie. by default the
> notification is disabled, but a new syscall sets up the process to be
> notified of CPU up/down events, on a signal # picked by the app. But this
> this indeed is dbus domain ...

Yeah, this workaround because we can't add a new signal isn't very
good, though ("I can't add a new signal, so you choose!"). In
practice, it sucks for libraries and it sucks for children.

As you point out, DBUS is a better solution anyway. Of course,
proposing that something which doesn't yet exist will solve all our
problems is usually a sign of laziness or optimism 8).

Cheers,
Rusty.
--
Anyone who quotes me in their sig is an idiot. -- Rusty Russell.
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