Recommended SMP Config

[Tom Daly]

Hi,
I'm running FreeBSD 6.0 Release (amd64) on Dell Poweredge 2850s. So far, 
so good. I'm doing a pretty vanilla install of things, enabling SMP in the 
kernel, and that's pretty much it. This server has 2 EM64T CPUs in it.

When looking at top, CPU 1 rarely shows up with processes on it. systat 
does show it idle most of the time. Why is this? Why do processes land on 
CPU 0, 2, and 3 in most cases.

Also, by setting machdep.hyperthreading_allowed=1, CPU 1 starts taking 
process onto it.

Output from dmesg:

CPU: Intel(R) Xeon(TM) CPU 3.00GHz (2992.71-MHz K8-class CPU)
   Origin = "GenuineIntel"  Id = 0xf43  Stepping = 3

Features=0xbfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,C
MOV,PAT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE>
   Features2=0x641d<SSE3,RSVD2,MON,DS_CPL,CNTX-ID,CX16,<b14>>
   AMD Features=0x20100800<SYSCALL,NX,LM>
   Hyperthreading: 2 logical CPUs
real memory  = 5368709120 (5120 MB)
avail memory = 4118777856 (3927 MB)
ACPI APIC Table: <DELL   PE BKC  >
FreeBSD/SMP: Multiprocessor System Detected: 4 CPUs
  cpu0 (BSP): APIC ID:  0
  cpu1 (AP): APIC ID:  1
  cpu2 (AP): APIC ID:  6
  cpu3 (AP): APIC ID:  7

Can someone clarify this for me?

Thanks,
Tom

-- 
Thomas J. Daly
tom at dyndns.com
Dynamic Network Services, Inc.
http://www.dyndns.com/