Re: 2.6.27rc1 cannot boot more than 8CPUs

Ingo Molnar
2008-08-15T14:07:27Z

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

>>> 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
>>
>
> Attached. cpu.8
> CONFIG_X86_32=y
> CONFIG_X86_PC=y
> CONFIG_X86=y
> CONFIG_NR_CPUS=8
>
> Attached. cpu.16
> CONFIG_X86_32=y
> CONFIG_X86_PC=y
> CONFIG_X86=y
> CONFIG_NR_CPUS=16
>
> Attached cpu.16.big
> CONFIG_X86_32=y
> CONFIG_X86=y
> CONFIG_X86_GENERICARCH=y
> CONFIG_X86_BIGSMP=y
> # CONFIG_X86_PC is not set
> CONFIG_NR_CPUS=16
>
> Attached cpu.16.nobig (same as cpu.16 except with modifed patch)
> CONFIG_X86_32=y
> CONFIG_X86_PC=y
> CONFIG_X86=y
> CONFIG_NR_CPUS=16
>
> Attached is the modified patch to make the warning appears. It's
> Yinghai's patch modified to just display the error and continue to
> boot.

thanks. To make sure it's all sorted out you might want to boot today's
tip/master and check whether it just does the right thing by default.
(it really should)

Ingo