[NTLUG:Discuss] possible processor problems

Wed Feb 15 11:06:13 CST 2006

In systems I've used, 2 CPU's show up as 4 (CPU#0-3) when 
hyperthreading is available.  It should show up in dmesg, /proc/cpuinfo, 
top, and any other place.

The BIOS will only show 2 processors when booting.  It does not care or 
know about hyperthreading.  You might want to reboot and see if both 
processors show up.  If not, you've lost a physical CPU.

It is possible, via software, to turn off hyperthreading and may be 
advised in some cases.  The newer BIOSes may be able to turn it off as 
well.  Is it possible that is happening?

...Ken

MontyS at videopost.com wrote:
> Stuart,
> 
> I wasn't sure if I was interpreting the logs correctly, or if the logs
> reported the cpu stat differently between distributions (although unlikely).
> Do I have only one physical cpu working with ht, or do I have 2 processors
> working with no ht?  Why the difference?  Surely FC4 with with a 2.6.x
> kernel can deal with ht, at least one would think.
> 
> The questionable server is having issues with gigabit file transfers where
> the files are over 1gig in size.  I remember reading "somewhere" that
> gigabit nics and/or transfers are more cpu intensive than 100baseT nics.
> So, when I looked at /proc/cpuinfo, and didn't see 4 cpus indicated, my
> curiosity was raised.  (100baseT transfers work fine, using the same onboard
> nics and 3Com 3870 switch.)
> 
> Anyway, I want to respect the group and not delve into off-topic
> hardware/networking issues on the list.  Just wanted to make sure FC4 was
> reporting correctly, and I was interpreting the logs correctly.
> 
> Thanks as always for your help.
> 
> Monty
> 
> 
> -----Original Message-----
> From: Stuart Johnston [mailto:saj at thecommune.net]
> Sent: Tuesday, February 14, 2006 6:36 PM
> To: NTLUG Discussion List
> Subject: Re: [NTLUG:Discuss] possible processor problems
> 
> 
> What is making you think that one is missing a CPU?  Both log files show 
> two physical CPUs.  The first one does not seem to be using 
> HyperThreading.  Is that the problem?
> 
> 
> MontyS at videopost.com wrote:
>> Greetings.
>>
>> I have 2 dual processor servers with Xeon processors on Supermicro
>> motherboards.  It appears that one of the servers has lost a processor.  I
>> am not positive, however, since I am running different versions of linux
> on
>> each server.
>>
>> The server that appears to be less one processor is running Fedora Core 4.
>> The server that appears correct is running RHES3.  I guess I want to make
>> sure Fedora Core 4 reports the correct number of processors.
>>
>> Below is the >>uname -r<< and grepped message log files after a reboot.
> The
>> dmesg log file doesn't illuminate the problem any, except the server with
>> the problem indicates that the Xeon processors are Lindhurst.  Again, I
>> don't know if that makes any difference.
>>
>> Please forgive the length of this email.
>>
>> Thanks as always for your help.
>>
>> Monty
>>
>>>> Questionable server<<
>> Linux  2.6.13-1.1526_FC4smp #1 SMP Wed Sep 28 19:30:04 EDT 2005 i686 i686
>> i386 GNU/Linux
>>
>> Feb 14 09:03:33  kernel: Initializing CPU#0
>> Feb 14 09:03:33  kernel: CPU 0 irqstacks, hard=c043b000 soft=c041b000
>> Feb 14 09:03:34  kernel: CPU: Trace cache: 12K uops, L1 D cache: 16K
>> Feb 14 09:03:34  kernel: CPU: L2 cache: 1024K
>> Feb 14 09:03:34  kernel: CPU: Physical Processor ID: 0
>> Feb 14 09:03:34  kernel: Intel machine check reporting enabled on CPU#0.
>> Feb 14 09:03:34  kernel: CPU0: Intel P4/Xeon Extended MCE MSRs (24)
>> available
>> Feb 14 09:03:34  kernel: CPU0: Thermal monitoring enabled
>> Feb 14 09:03:34  kernel: CPU0: Intel(R) Xeon(TM) CPU 3.00GHz stepping 01
>> Feb 14 09:03:34  kernel: CPU 1 irqstacks, hard=c043c000 soft=c041c000
>> Feb 14 09:03:34  kernel: Initializing CPU#1
>> Feb 14 09:03:34  kernel: CPU: Trace cache: 12K uops, L1 D cache: 16K
>> Feb 14 09:03:34  kernel: CPU: L2 cache: 1024K
>> Feb 14 09:03:34  kernel: CPU: Physical Processor ID: 3
>> Feb 14 09:03:34  kernel: Intel machine check reporting enabled on CPU#1.
>> Feb 14 09:03:34  kernel: CPU1: Intel P4/Xeon Extended MCE MSRs (24)
>> available
>> Feb 14 09:03:34  kernel: CPU1: Thermal monitoring enabled
>> Feb 14 09:03:34  kernel: CPU1: Intel(R) Xeon(TM) CPU 3.00GHz stepping 01
>> Feb 14 09:03:34  kernel: checking TSC synchronization across 2 CPUs:
> passed.
>> Feb 14 09:03:34  kernel: Brought up 2 CPUs
>> Feb 14 10:27:58  kernel: Initializing CPU#0
>> Feb 14 10:27:58  kernel: CPU 0 irqstacks, hard=c043b000 soft=c041b000
>> Feb 14 10:27:58  kernel: CPU: Trace cache: 12K uops, L1 D cache: 16K
>> Feb 14 10:27:58  kernel: CPU: L2 cache: 1024K
>> Feb 14 10:27:58  kernel: CPU: Physical Processor ID: 0
>> Feb 14 10:27:58  kernel: Intel machine check reporting enabled on CPU#0.
>> Feb 14 10:27:58  kernel: CPU0: Intel P4/Xeon Extended MCE MSRs (24)
>> available
>> Feb 14 10:27:58  kernel: CPU0: Thermal monitoring enabled
>> Feb 14 10:27:58  kernel: CPU0: Intel(R) Xeon(TM) CPU 3.00GHz stepping 01
>> Feb 14 10:27:59  kernel: CPU 1 irqstacks, hard=c043c000 soft=c041c000
>> Feb 14 10:27:59  kernel: Initializing CPU#1
>> Feb 14 10:27:59  kernel: CPU: Trace cache: 12K uops, L1 D cache: 16K
>> Feb 14 10:27:59  kernel: CPU: L2 cache: 1024K
>> Feb 14 10:27:59  kernel: CPU: Physical Processor ID: 3
>> Feb 14 10:27:59  kernel: Intel machine check reporting enabled on CPU#1.
>> Feb 14 10:27:59  kernel: CPU1: Intel P4/Xeon Extended MCE MSRs (24)
>> available
>> Feb 14 10:27:59  kernel: CPU1: Thermal monitoring enabled
>> Feb 14 10:27:59  kernel: CPU1: Intel(R) Xeon(TM) CPU 3.00GHz stepping 01
>> Feb 14 10:27:59  kernel: checking TSC synchronization across 2 CPUs:
> passed.
>> Feb 14 10:27:59  kernel: Brought up 2 CPUs
>>
>>>> known good server<<
>> Linux  2.4.21-20.ELsmp #1 SMP Wed Aug 18 20:46:40 EDT 2004 i686 i686 i386
>> GNU/Linux
>>
>> Feb 14 17:52:49  kernel: CPU 0 (0x0000) enabledProcessor #0 Pentium 4(tm)
>> XEON(tm) APIC version 20
>> Feb 14 17:52:49  kernel: CPU 1 (0x0600) enabledProcessor #6 Pentium 4(tm)
>> XEON(tm) APIC version 20
>> Feb 14 17:52:49  kernel: CPU 2 (0x0100) enabledProcessor #1 Pentium 4(tm)
>> XEON(tm) APIC version 20
>> Feb 14 17:52:49  kernel: CPU 3 (0x0700) enabledProcessor #7 Pentium 4(tm)
>> XEON(tm) APIC version 20
>> Feb 14 17:52:49  kernel: 4 CPUs total
>> Feb 14 17:52:49  kernel: Enabling the CPU's according to the ACPI table
>> Feb 14 17:52:49  kernel: Initializing CPU#0
>> Feb 14 17:52:49  kernel: CPU: Trace cache: 12K uops, L1 D cache: 8K
>> Feb 14 17:52:49  kernel: CPU: L2 cache: 512K
>> Feb 14 17:52:49  kernel: CPU: Physical Processor ID: 0
>> Feb 14 17:52:49  kernel: Intel machine check reporting enabled on CPU#0.
>> Feb 14 17:52:49  kernel: CPU: Trace cache: 12K uops, L1 D cache: 8K
>> Feb 14 17:52:49  kernel: CPU: L2 cache: 512K
>> Feb 14 17:52:49  kernel: CPU: Physical Processor ID: 0
>> Feb 14 17:52:49  kernel: Intel machine check reporting enabled on CPU#0.
>> Feb 14 17:52:49  kernel: CPU0: Intel(R) Xeon(TM) CPU 2.66GHz stepping 05
>> Feb 14 17:52:49  kernel: per-CPU timeslice cutoff: 1463.11 usecs.
>> Feb 14 17:52:49  kernel: enabled ExtINT on CPU#0
>> Feb 14 17:52:49  kernel: Initializing CPU#1
>> Feb 14 17:52:49  kernel: masked ExtINT on CPU#1
>> Feb 14 17:52:49  kernel: CPU: Trace cache: 12K uops, L1 D cache: 8K
>> Feb 14 17:52:49  kernel: CPU: L2 cache: 512K
>> Feb 14 17:52:49  kernel: ACPI tables and CPU MSR values mismatch about cpu
>> number
>> Feb 14 17:52:49  kernel: CPU: Physical Processor ID: 3
>> Feb 14 17:52:49  kernel: Intel machine check reporting enabled on CPU#1.
>> Feb 14 17:52:49  kernel: CPU1: Intel(R) Xeon(TM) CPU 2.66GHz stepping 05
>> Feb 14 17:52:49  kernel: Initializing CPU#2
>> Feb 14 17:52:49  kernel: masked ExtINT on CPU#2
>> Feb 14 17:52:49  kernel: CPU: Trace cache: 12K uops, L1 D cache: 8K
>> Feb 14 17:52:49  kernel: CPU: L2 cache: 512K
>> Feb 14 17:52:49  kernel: CPU: Physical Processor ID: 0
>> Feb 14 17:52:49  kernel: Intel machine check reporting enabled on CPU#2.
>> Feb 14 17:52:49  kernel: CPU2: Intel(R) Xeon(TM) CPU 2.66GHz stepping 05
>> Feb 14 17:52:49  kernel: Initializing CPU#3
>> Feb 14 17:52:49  kernel: masked ExtINT on CPU#3
>> Feb 14 17:52:49  kernel: CPU: Trace cache: 12K uops, L1 D cache: 8K
>> Feb 14 17:52:49  kernel: CPU: L2 cache: 512K
>> Feb 14 17:52:49  kernel: CPU: Physical Processor ID: 3
>> Feb 14 17:52:49  kernel: Intel machine check reporting enabled on CPU#3.
>> Feb 14 17:52:49  kernel: CPU3: Intel(R) Xeon(TM) CPU 2.66GHz stepping 05
>> Feb 14 17:52:49  kernel: ..... CPU clock speed is 2666.0648 MHz.
>> Feb 14 17:52:49  kernel:
> CPU0<T0:1333024,T1:1066416,D:2,S:266606,C:1333030>
>> Feb 14 17:52:49  kernel: CPU1<T0:1333024,T1:799808,D:4,S:266606,C:1333030>
>> Feb 14 17:52:49  kernel:
> CPU2<T0:1333024,T1:533184,D:22,S:266606,C:1333030>
>> Feb 14 17:52:49  kernel: CPU3<T0:1333024,T1:266592,D:8,S:266606,C:1333030>
>> Feb 14 17:52:50  kernel: mapping CPU#0's runqueue to CPU#2's runqueue.
>> Feb 14 17:52:50  kernel: mapping CPU#1's runqueue to CPU#3's runqueue.
>> _______________________________________________
>> https://ntlug.org/mailman/listinfo/discuss
> 
> 
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