Hyperthreading Issues

Arthur Hartwig arthur.hartwig at nokia.com
Tue Oct 10 10:40:17 PDT 2006


ext kumaresh pandian wrote:
> Hi all
>    
>    
>   How do i Find if the CPU is Hyperthreading enabled or not? I have tried using the mtables but i'm not able to figure it out.
>   
Look for the HTT bit in the CPU features displayed when FreeBSD starts 
up. Here's an example from one of my systems, HTT is third from the 
right hand end of the CPU features list.

Copyright (c) 1992-2005 The FreeBSD Project.
Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993, 1994
        The Regents of the University of California. All rights reserved.
hartwig 1 10.09.2006-151040MPTable: <OEM ID   PRODUCT ID  >
Timecounter "i8254" frequency 1193182 Hz quality 0
CPU: Intel(R) Xeon(TM) CPU 2.80GHz (2794.59-MHz 686-class CPU)
  Origin = "GenuineIntel"  Id = 0xf27  Stepping = 7
  
Features=0xbfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE>
  Features2=0x4400<CNTX-ID,<b14>>
  Hyperthreading: 2 logical CPUs
real memory  = 2147483648 (2048 MB)
avail memory = 2100936704 (2003 MB)

Arthur
                                          



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