# Determining physical processors on SMT driven architectures

- From: Anantha Kiran Kandukuri \<hidden\>
- Date: 2005-09-29 05:25:59 
- List: linuxppc-dev
- Page: https://ratatoskr.run/linuxppc-dev/2005/09/9401039
- Thread: https://ratatoskr.run/linuxppc-dev/2005/09/9401039/t.md

```text
Hi,
Is there a programatical way of caliculating physical CPUs on IBM
SMT driven archtitural machines.

I am aware of commands of sort "lsdev -C -c processor" and "smtctl".
But is there any API to do same thing. I saw "processor_info"
strucutre in "/usr/include/sys/iplcb.h" contains information i am
looking for. Is there a way to access this.

Linux on IntelHT, stores this info in "/proc/cpuinfo" file. Similarly
AIX stores this info in "/dev/pmem" file. In KDB, "ipl" subcommand
actually parses file "/dev/pmem" to access "processor_info" strctures.
Can i simulate these KDB commands in a programatical fashion.

Atleast, are there "CPUID" sort of assembly instructions in AIX, so
that i can probe for actual number of CPUs.

Any help is appreciated.

Thanks
-Ananth
--
```