Re: 2.6.27rc1 cannot boot more than 8CPUs

[Ingo Molnar]

* Jeff Chua <jeff.chua.linux@xxxxxxxxx> wrote:

> On Thu, Aug 14, 2008 at 2:33 AM, Yinghai Lu <yhlu.kernel@xxxxxxxxx> wrote:
> 
> >>>> > With 16 CPUs, it still hangs, but now the console is showing the
> >>>> > errors as intended.
> >>>> > ... but it is supposed to hang?
> 
> > please check the attached patch. it should fix the new regression and
> > will not hang.
> 
> Ok, booted up and not hanged, but those messages below don't show up
> anywhere. I've tested with CONFIG_NR_CPUS=16 and 8 as well. Just got 8
> cpus
> 
> More than 8 CPUs detected - skipping them.
> Use CONFIG_X86_GENERICARCH and CONFIG_X86_BIGSMP.
> 
> # cat /sys/devices/system/cpu/possible
> 0-7
> 
> CONFIG_X86_32=y
> CONFIG_X86_PC=y
> 
> 
> Looks like it's not going into this condition
> +        if (def_to_bigsmp && nr_cpu_ids > 8) {
> 
> 
> Shall this be put back so that it'll show the message?
> -       if (def_to_bigsmp && apicid > 8) {
> -               printk(KERN_WARNING
> -                       "More than 8 CPUs detected - skipping them.\n"
> -                       "Use CONFIG_X86_GENERICARCH and CONFIG_X86_BIGSMP.\n");
> -       }

could you post the full dmesg? And the modified patch that you've tested 
to both have 8 CPUs without bigsmp and which also shows the printk?

	Ingo
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