Trying to undertand CPU info on a LDOM and it's Control Domain

Question

I want to know the number of physical cpus and cores in a control domain and LDOM.

In this LDOM environment, I have a control domain with two LDOMs

If I do a psrinfo -p on the control domain, it indicates 1 chip and the following

The physical processor has 8 virtual processors (0-7)
SPARC-T4 (chipid 0, clock 2848 MHz)

I don't see any indication that it has cores. But if I do:

kstat cpu_info | grep core_id  | sort -u | wc -l

It indicates I have 1 core.

But if I do ldm list -e <name of ldom>, I see this core info:

CORE
CID    CPUSET
10     (80, 81, 82, 83, 84, 85, 86, 87)
11     (88, 89, 90, 91, 92, 93, 94, 95)
12     (96, 97, 98, 99, 100, 101, 102, 103)
13     (104, 105, 106, 107, 108, 109, 110, 111)
14     (112, 113, 114, 115, 116, 117, 118, 119)
15     (120, 121, 122, 123, 124, 125, 126, 127)

So, I see 6 cores and I'm confused. So why do I see 1 core with the kstat command but see 6 cores with ldm list -e <NAME of LDOM>?

If I log into the LDOM and do a psrinfo -pv, I see 6 cores which matches what ldm list -e <name of LDOM> on the Control Domain.

root@xxxxxxx0:~# psrinfo -pv
The physical processor has 6 cores and 48 virtual processors (0-47)
The core has 8 virtual processors (0-7)
The core has 8 virtual processors (8-15)
The core has 8 virtual processors (16-23)
The core has 8 virtual processors (24-31)
The core has 8 virtual processors (32-39)
The core has 8 virtual processors (40-47)
SPARC-T4 (chipid 0, clock 2848 MHz)

Answer 1

I contacted Oracle/Solaris technical support, here is there answer.

When you use OS commands, such as psrinfo, you’ll only see what the OS can see. So when you do that in the primary or a guest ldom you’ll only see what resources they’ve been allocated.

However, when you use ldm in the primary you’re communicating with the ldomsmanager, (ldmd). So, you can see what resources have been allocated to the primary and all the guest ldoms. As you know, ldmd only runs in the primary.

Have a look at:

ldm list-rsrc-group [-a] [-d domain] [–l] [-o core|memory|io]

This gives you quite a lot of information about the resource allocations that you can’t see from the OS commands.