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Date:      Thu, 5 Apr 2007 10:38:28 -0700
From:      Mark Messier <mark@messier.com>
To:        Garrett Cooper <youshi10@u.washington.edu>
Cc:        freebsd-questions@freebsd.org
Subject:   Re: trouble with HT
Message-ID:  <30662671-669D-401E-A63D-048A224F80DD@messier.com>
In-Reply-To: <46145B8F.3010109@u.washington.edu>
References:  <20070403194555.4a9d1f2f.freebsd@dfwlp.com>	<20070404005721.GA19966@xor.obsecurity.org>	<20070403212527.b94753ea.freebsd@dfwlp.com> <4613848B.5080306@tiscali.it> <46145B8F.3010109@u.washington.edu>
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 >> You also need to add:
 >> kern.smp.active = 1
 >> kern.smp.cpus = 1

What?  I've never added lines like those...
They always seem to have the correct values for me:

Here it is on 4.8:

  # sysctl -a | grep smp
  machdep.smp_active: 1
  machdep.smp_cpus: 2

and 5.3:

  # sysctl -a | grep smp
  kern.timecounter.smp_tsc: 0
  kern.smp.maxcpus: 16
  kern.smp.active: 1
  kern.smp.disabled: 0
  kern.smp.cpus: 2
  kern.smp.forward_signal_enabled: 1
  kern.smp.forward_roundrobin_enabled: 1

and 6.1:

  # sysctl -a | grep smp
  kern.timecounter.smp_tsc: 0
  kern.smp.maxcpus: 16
  kern.smp.active: 1
  kern.smp.disabled: 0
  kern.smp.cpus: 4
  kern.smp.forward_signal_enabled: 1
  kern.smp.forward_roundrobin_enabled: 1

and 6.2:

  # sysctl -a | grep smp
  kern.timecounter.smp_tsc: 0
  kern.smp.forward_roundrobin_enabled: 1
  kern.smp.forward_signal_enabled: 1
  kern.smp.cpus: 4
  kern.smp.disabled: 0
  kern.smp.active: 1
  kern.smp.maxcpus: 16

Now, on that 6.1 system, it boots as:

  CPU: Intel(R) Xeon(TM) CPU 3.40GHz (3391.51-MHz 686-class CPU)
    Origin = "GenuineIntel"  Id = 0xf4a  Stepping = 10
    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=0x649d<SSE3,RSVD2,MON,DS_CPL,EST,CNTX-ID,CX16,<b14>>
    AMD Features=0x20100000<NX,LM>
    AMD Features2=0x1<LAHF>
    Logical CPUs per core: 2

  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

but all I ever see in 'top' is cpu 0 and 2 doing anything.

Meanwhile, on a 6.2 Dempsey system with this:

CPU: Intel(R) Xeon(R) CPU            5130  @ 2.00GHz (2000.08-MHz K8- 
class CPU)
   Origin = "GenuineIntel"  Id = 0x6f6  Stepping = 6
    
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=0x4e33d<SSE3,RSVD2,MON,DS_CPL,VMX,TM2,<b9>,CX16,<b14>,<b15>,<b 
18>>
   AMD Features=0x20100800<SYSCALL,NX,LM>
   AMD Features2=0x1<LAHF>
   Cores per package: 2

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

I see CPU 0,1,2 and 3 in the top output.

What's up with that 6.1 machine showing only cpu 0 and 2?   The CPU  
are listed here:

http://processorfinder.intel.com/details.aspx?sSpec=SL8P4

Thanks,
-mark

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