Re: 2.6.27rc1 cannot boot more than 8CPUs

Ingo Molnar
2008-08-14T09:07:59Z

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

> On Thu, Aug 14, 2008 at 2:33 AM, Yinghai Lu <yhlu.kernel@gmail.com> 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