Re: regression in 2.6.23-rc8 - power off failed

[Rafael J. Wysocki]

On Saturday, 29 September 2007 22:47, Bill Davidsen wrote:
> Alexey Starikovskiy wrote:
> 
> > -static void
> > -acpi_power_off (void)
> > -{
> > -       printk("%s called\n",__FUNCTION__);
> > -       /* Some SMP machines only can poweroff in boot CPU */
> > -       set_cpus_allowed(current, cpumask_of_cpu(0));
> > ACPI in kernel 2.6.12 did disable non-boot cpus too in powe_off.
> > Later only comment was left for some reason...
> > 
> Am I midreading that code, or does it really assume that the boot cpu is 
> always zero? Or just that zero will be able to do the power off?
> 
> In any case I have had an SMP machine which did not have a CPU zero, and 
> it was discussed here, I believe. Wonder what happens if you set 
> affinity to a CPU you don't have...

Good question, but it also caused other problems to appear, IIRC.

IMHO, it's better to call disable_nonboot_cpus() in an appropriate place
anyway.

Greetings,
Rafael
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/