February 24, 2013

How to find the count of physical processors, cores and threads on Solaris?

Let’s first understand the terms and relationship between the same quickly.

Physical processor – processor that is actually / physically present
Core – further division of physical processor i.e. a physical processor can contain multiple cores
Thread – a distinct execution path provided by a core i.e. a core can support multiple threads
Virtual processor – can be considered equivalent to a thread

That means, Number of virtual processors in a physical processor = count (cores) * count(threads).

psrinfo -p gives the number of physical processors

psrinfo -pv gives the number of virtual processors per each physical processor

But, how does one find the number of cores / threads on a physical processor? The only way that this could be found out is by going to the specs page on Sun/Oracle website. However, recent updates of Solaris 10 did include a fix to report this kind of detail. In case the fix is not there, it can still be found out from the command “kstat cpu_info”. For more details, you may refer to http://blogs.oracle.com/sistare/entry/cpu_to_core_mapping.

No comments: