Hyperthreading hurts 5.3?

Anthony Atkielski atkielski.anthony at wanadoo.fr
Tue Jan 11 22:20:17 PST 2005


Jonathan Chen writes:

JC> Not true on 5.3+ GENERIC systems. If you look at dmesg, you'll see the
JC> second virtual CPU launched as well as the extra column in top(1) if
JC> you enable HTT in the BIOS.

Well, now I'm confusing.  I have an Asus P4P800-E Deluxe MB with an
Intel P4 processor mounted on it, and dmesg looks like this:

FreeBSD 5.3-RELEASE #1: Mon Dec 27 05:52:34 CET 2004
    root at freebie.atkielski.com:/usr/obj/usr/src/sys/FREEBIE
ACPI APIC Table: <A M I  OEMAPIC >
Timecounter "i8254" frequency 1193182 Hz quality 0
CPU: Intel(R) Pentium(R) 4 CPU 3.00GHz (2998.57-MHz 686-class CPU)
  Origin = "GenuineIntel"  Id = 0xf34  Stepping = 4
  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>
  Hyperthreading: 2 logical CPUs
real memory  = 1073414144 (1023 MB)
avail memory = 1045057536 (996 MB)
ioapic0: Changing APIC ID to 2
ioapic0 <Version 2.0> irqs 0-23 on motherboard
npx0: [FAST]
npx0: <math processor> on motherboard
npx0: INT 16 interface
acpi0: <A M I OEMRSDT> on motherboard
acpi0: Power Button (fixed)
Timecounter "ACPI-fast" frequency 3579545 Hz quality 1000
acpi_timer0: <24-bit timer at 3.579545MHz> port 0x808-0x80b on acpi0
cpu0: <ACPI CPU> on acpi0
pcib0: <ACPI Host-PCI bridge> port 0xcf8-0xcff on acpi0
pci0: <ACPI PCI bus> on pcib0
agp0: <Intel 82865 host to AGP bridge> mem 0xf8000000-0xfbffffff at device 0.0 on pci0
pcib1: <ACPI PCI-PCI bridge> at device 1.0 on pci0
pcib1: could not get PCI interrupt routing table for \\_SB_.PCI0.P0P1 - AE_NOT_FOUND
pci1: <ACPI PCI bus> on pcib1
pci1: <display, VGA> at device 0.0 (no driver attached)
[...]

Do I have two processors or not?  The BIOS says that hyperthreading is
enabled (and it wouldn't say anything at all if the processor were not
HT-capable, according to the manual).

Where's the second logical processor?  I recompiled my own kernel but I
didn't modify any of the CPU stuff (I don't think).

-- 
Anthony




More information about the freebsd-questions mailing list