Re: [Bugme-new] [Bug 7495] New: Kernel periodically hangs.

From: Dave Jones
Date: Sun Nov 12 2006 - 16:47:41 EST


On Sun, Nov 12, 2006 at 03:16:38PM +0100, Arjan van de Ven wrote:
>
> > > We KNOW it can't work on a sizable amount of machines. This is why it
> > > is a config option; you can enable it if YOUR machine is KNOWN to work,
> > > and you get some gains. But it's also understood that it often it won't
> > > work. So any sensible distro (since they have to aim for a wide
> > > audience) disables this option ...
> >
> > Nowadays, many distributions only ship CONFIG_SMP=y kernels...
>
> that's a calculated risk on their side (and they know that); they're
> balancing not functioning on a set of machines off against needing more
> kernels.

Andi has a nice patch in the suse kernel which adds heuristics to disable
apic on systems where it isn't likely to work. It DTRT in at least
one problem case that I know of. The actual fall-out from enabling
'run SMP kernels on UP i686' for FC6 has mostly been a non-event.
Literally a handful of cases, that will likely all get caught and worked
around by Andi's patch or similar.

Dave

--
http://www.codemonkey.org.uk
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