8.1-PRERELEASE: CPU packages not detected correctly

[Jung-uk Kim]

On Wednesday 14 July 2010 01:31 pm, Andriy Gapon wrote:
> on 14/07/2010 17:14 Oliver Fromme said the following:
> > In a machine installed yesterday, 8.1-PRERELEASE doesn't
> > seem to detect the number of CPU packages vs. cores per
> >
> > package correctly:
> >  | FreeBSD 8.1-PRERELEASE-20100713 #0: Tue Jul 13 19:51:18 UTC
> >  | 2010 [...]
> >  | CPU: Intel(R) Xeon(R) CPU           L5408  @ 2.13GHz
> >  | (2133.42-MHz K8-class CPU) Origin = "GenuineIntel"  Id =
> >  | 0x1067a  Family = 6  Model = 17  Stepping = 10
> >  | Features=0xbfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SE
> >  |P,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE
> >  |2,SS,HTT,TM,PBE>
> >  | Features2=0x40ce3bd<SSE3,DTES64,MON,DS_CPL,VMX,EST,TM2,SSSE3,C
> >  |X16,xTPR,PDCM,DCA,SSE4.1,XSAVE> AMD
> >  | Features=0x20000800<SYSCALL,LM>
> >  |   AMD Features2=0x1<LAHF>
> >  |   TSC: P-state invariant
> >  | real memory  = 34359738368 (32768 MB)
> >  | avail memory = 33151377408 (31615 MB)
> >  | ACPI APIC Table: <IBM    SERBLADE>
> >  | FreeBSD/SMP: Multiprocessor System Detected: 8 CPUs
> >  | FreeBSD/SMP: 1 package(s) x 8 core(s)
> >  |  cpu0 (BSP): APIC ID:  0
> >  |  cpu1 (AP): APIC ID:  1
> >  |  cpu2 (AP): APIC ID:  2
> >  |  cpu3 (AP): APIC ID:  3
> >  |  cpu4 (AP): APIC ID:  4
> >  |  cpu5 (AP): APIC ID:  5
> >  |  cpu6 (AP): APIC ID:  6
> >  |  cpu7 (AP): APIC ID:  7
> >  | ioapic1 <Version 2.0> irqs 24-47 on motherboard
> >  | ioapic0 <Version 2.0> irqs 0-23 on motherboard
> >
> > I'm pretty sure that this is a 2 x 4 machine (2 CPU packages
> > with 4 cores per package), not 1 x 8.  That's what the BIOS
> > displays during POST.
> >
> > I'm not sure if this is just a "cosmetic" issue, or if this
> > is a critical thing ...  I could imagine that performance
> > might be sub-optimal if the CPU topology isn't detected
> > correctly, but I'm not sure if FreeBSD can take advantage
> > of the topology.
>
> Could you please try to do the following?
> 1. Fetch topo-12212009.tar from the top of this page:
> http://software.intel.com/en-us/articles/intel-64-architecture-proc
>essor-topology-enumeration/ 2. Untar it and apply this patch to the
> code:
> http://people.freebsd.org/~avg/cpu-topology.diff
> 3. Compile it by running sh mk_64.sh (supposing you have amd64
> system installed) 4. Run cpu_topology64.out and report back its
> output.

It's funny that I actually wrote a convenience script (and cleaned up 
today):

http://people.freebsd.org/~jkim/cpu_topology-12212009.sh

BTW, current topology detection code is not optimal for some Intel 
processors if my memory serves.

Jung-uk Kim