Messages in this thread | | | Date | Wed, 13 Aug 2008 10:46:43 -0700 | From | "Yinghai Lu" <> | Subject | Re: 2.6.27rc1 cannot boot more than 8CPUs |
| |
On Wed, Aug 13, 2008 at 10:39 AM, Ingo Molnar <mingo@elte.hu> wrote: > > * Jeff Chua <jeff.chua.linux@gmail.com> wrote: > >> On Thu, Aug 14, 2008 at 1:10 AM, Jeff Chua <jeff.chua.linux@gmail.com> wrote: >> > On Wed, Aug 13, 2008 at 10:16 PM, Ingo Molnar <mingo@elte.hu> wrote: >> > >> >> btw., could you please check that v2.6.27-rc3 (or later) kernels boot >> >> fine (with about 8 cpus) even if you have genericarch/bigsmp disabled, >> >> and do not silently hang as it happened on your box before? >> > >> > With 16 CPUs, it still hangs, but now the console is showing the >> > errors as intended. >> > ... but it is supposed to hang? >> >> I tried with just CONFIG_NR_CPUS=8 and this time it booted, but stange >> thing is I only see 2 CPUs! To be more precise, it's without both >> CONFIG_X86_GENERICARCH and CONFIG_X86_BIGSMP. >> >> And when I tried to enable the CPUs, it complained about: >> >> # cat cpu6/online >> 0 >> # echo 1 > cpu6/online >> More than 8 CPUs detected - skipping them. >> Use CONFIG_X86_GENERICARCH and CONFIG_X86_BIGSMP. >> -bash: echo: write error: Input/output error >> >> Prior to the patch, the system booted with all 8 CPUs.
that is new regression...
>> >> Again, if I enable both CONFIG_X86_GENERICARCH and CONFIG_X86_BIGSMP, >> I get all 16 CPUs. > > Yinghai, could the APIC ID enumeration be nonsequential and we skip CPUs > starting at the third one already? I think we should accept all CPUs > that are within our support range.
will try to clear those bits on smp_sanity_check...
YH
| |