Re: 2.6.25-rc3-git3: Reported regressions from 2.6.24

[Andrew Morton <akpm@linux-foundation.org>]

On Thu, 6 Mar 2008 20:55:25 +0100 (CET)
Guennadi Liakhovetski <g.liakhovetski@gmx.de> wrote:

> On Thu, 6 Mar 2008, Ingo Molnar wrote:
> 
> > 
> > * Rafael J. Wysocki <rjw@sisk.pl> wrote:
> > 
> > > Bug-Entry	: http://bugzilla.kernel.org/show_bug.cgi?id=10123
> > > Subject		: No power-off / reboot with 2.6.25-rcX (up to -rc3) kernels
> > > Submitter	: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
> > > Date		: 2008-02-27 08:15
> > 
> > Guennadi bisected this down to:
> > 
> >   commit fd7d1ced29e5beb88c9068801da7a362606d8273
> >   PCI: make pci_bus a struct device
> > 
> > and it's suspected that Andrew's poweroff problems might be related as 
> > well. Guennadi, Andrew, find below a manual revert of this change - does 
> > it make any difference?
> 
> Yes, this patch fixes both startup warnings and lets the system reboot and 
> power off again!

Ingo's revert doesn't fix my machine-wont-power-off regression.


Reminder: what _does_ fix it is:

a) CONFIG_DETECT_SOFTLOCKUP=n or

b) This:

--- a/kernel/softlockup.c~softlockup-workaround
+++ a/kernel/softlockup.c
@@ -289,6 +289,7 @@ cpu_callback(struct notifier_block *nfb,
 	case CPU_DEAD_FROZEN:
 		p = per_cpu(watchdog_task, hotcpu);
 		per_cpu(watchdog_task, hotcpu) = NULL;
+		msleep(1);
 		kthread_stop(p);
 		break;
 #endif /* CONFIG_HOTPLUG_CPU */
_


this one is unrelated to Greg's patch, I think.  It's a timing thing.