Number of CPUs in a ML370?

[Dan Mahoney]

I'm trying to figure out how many CPUs are present in my ML370, based upon the output of "dmesg" (RedHat 8).

The relevant sections of the dmesg output contain:

Intel machine check architecture supported.
Intel machine check reporting enabled on CPU#0.

CPU: Trace cache: 12K uops, L1 D cache: 8K
CPU: L2 cache: 512K
CPU: Physical Processor ID: 0
Intel machine check reporting enabled on CPU#0.

CPU0: Intel(R) Xeon(TM) CPU 2.80GHz stepping 07

Booting processor 1/1 eip 2000
Initializing CPU#1
masked ExtINT on CPU#1

CPU: Trace cache: 12K uops, L1 D cache: 8K
CPU: L2 cache: 512K
CPU: Physical Processor ID: 0
Intel machine check reporting enabled on CPU#1.

CPU1: Intel(R) Xeon(TM) CPU 2.80GHz stepping 07
Booting processor 2/6 eip 2000
Initializing CPU#2
masked ExtINT on CPU#2

CPU: Trace cache: 12K uops, L1 D cache: 8K
CPU: L2 cache: 512K
CPU: Physical Processor ID: 3

CPU2: Intel(R) Xeon(TM) CPU 2.80GHz stepping 07
Booting processor 3/7 eip 2000

CPU: Trace cache: 12K uops, L1 D cache: 8K
CPU: L2 cache: 512K
CPU: Physical Processor ID: 3
Intel machine check reporting enabled on CPU#3.

CPU3: Intel(R) Xeon(TM) CPU 2.80GHz stepping 07
Total of 4 processors activated (22229.81 BogoMIPS).
cpu_sibling_map[0] = 1
cpu_sibling_map[1] = 0
cpu_sibling_map[2] = 3
cpu_sibling_map[3] = 2

It looks like 4 CPUs present, but the entries reading CPU: Physical Processor ID: [0 or 3] make me wonder.

[G. Vrijhoeven]

Hi Dan,

I can confurm you have 4 cpu' active!
The counting just starts with 0.

Gideon

[Dan Mahoney]

So fact that dmesg reports CPUs 0 and 1 as "Physical Processor 0" and CPUs 2 and 3 as "Physical Processor 1" isn't indicative of only 2 CPUs? I was hoping that was the case, was just confused by the "Physical Processor" lines.

Thanks!

[Paul Cooper_1]

You only have 2 physical CPU's in your 370 but it looks like they are hyperthreading - see http://www.intel.com/technology/hyperthread/index.htm?iid=sr+hyper& for more info.

Hope that helps

Paul

[Dan Mahoney]

Ah, that helps a lot! Thanks so much.

I sort of suspected there were only 2 physical CPUs, so I found the reports of 4 CPUs to be curiousl. Now I understand!