SMP with HTT disabled

[John Baldwin]

On Friday 27 May 2005 02:23 pm, Julian Elischer wrote:
> John Baldwin wrote:
> >On Thursday 26 May 2005 05:04 pm, Singh, Vijay wrote:
> >>Hello, I am trying to disable HTT to run some tests. From dmesg I have:
> >>
> >>CPU: Intel(R) Xeon(TM) CPU 2.66GHz (2666.77-MHz 686-class CPU)
> >>  Origin = "GenuineIntel"  Id = 0xf29  Stepping = 9
> >>
> >>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,S
> >>SE2,SS,HTT,TM,PBE>
> >>  Hyperthreading: 2 logical CPUs
> >>real memory  = 1073676288 (1023 MB)
> >>avail memory = 1041121280 (992 MB)
> >>ACPI APIC Table: <A M I  OEMAPIC >
> >>FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs
> >> cpu0 (BSP): APIC ID:  0
> >> cpu1 (AP): APIC ID:  1
> >>
> >># cat /boot/loader.conf
> >>machdep.hlt_logical_cpus=1
> >>
> >>And mptable output is below. It seems to me that the kernel does not
> >>bring up the 2nd physical CPU. Am I right or wrong.
> >
> >The kernel only sees 1 physical CPU.  The MPTable only shows 1 physical
> > CPU as well:
>
> note that mptable shows both HTT cpus on some motherboards and only one
> entry
> per chip on others.

Yes, but clearly, the MP Table is only listing 1 CPU, so the machine cannot 
have _2_ physical CPUs in it that the BIOS knows about.

> >>MP Config Base Table Entries:
> >>
> >>--
> >>
> >>Processors: APIC ID Version State Family Model Step Flags
> >>
> >>0 0x14 BSP, usable 15 2 9 0xbfebfbff
> >>
> >>--

-- 
John Baldwin <jhb at FreeBSD.org>  <><  http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve"  =  http://www.FreeBSD.org