Saman Barghi saman.b at gmail.com
Thu Feb 17 10:04:12 PST 2011

On Thu, Feb 17, 2011 at 12:37 PM, Joe Talbott <josepht at cstone.net> wrote:
On Thu, Feb 17, 2011 at 12:41:55PM -0500, Saman Barghi wrote:
> Hi,
> I wanted to know if DragonFlyBSD supports Hyper threading or not. I did some
> benchmarking recently and it seems that on a Xeon dual core with 2 virtual
> cpu per core, DFBSD only scale to 2 threads and after that the number of
> transactions/second dorps (using sysbench oltp). So does that mean DFBSD
> does not support Hyperthreading !? If that is the case, I need to perform
> the benchmarks on a different machine without hyper threading. Please kindly
> advise.

HyperThreading is certainly supported.  Do you have an SMP kernel
installed?  Perhaps your dmesg output would be helpful.

Isn't it enabled by default?! I thought it is. Anyway,  Here is the dmseg output. Please enlighten me and let me know how I can enable SMP as it seems it is not enabled from the dmesg. 
=============== dmesg.today ==================Copyright (c) 2003-2010 The DragonFly Project.Copyright (c) 1992-2003 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.DragonFly v2.8.2-RELEASE #2: Fri Oct 29 01:29:56 PDT 2010    dillon at office1.backplane.com:/usr/obj/usr/src-misc/sys/GENERICTSC clock: 3066101012 Hz, i8254 clock: 1193301 Hz
CPU: Intel(R) Xeon(TM) CPU 3.06GHz (3065.81-MHz 686-class CPU)  Origin = "GenuineIntel"  Id = 0xf25  Stepping = 5  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<CNXT-ID,xTPR>  Logical CPUs per core: 2real memory  = 2146497536 (2047 MB)avail memory = 2062565376 (1967 MB)module_register: module pci/ahci already exists!Module pci/ahci failed to register: 17
FQ scheduler policy version 1.0 loadedNo policy for md0 specified, or policy not founddisk scheduler: set policy of md0 to noop

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