This section lists the most important commands that you should know and explains where their data comes from.
CPU Control Commands — psrinfo, psradm, and psrset
psrinfo tells you which CPUs are in use and when they were last enabled or disabled. psradm actually controls the CPUs. Note that in server systems, interrupts are bound to specific CPUs to improve the cache hit rate, and clock interrupts always go to CPU 0. Even if a CPU is disabled, it still receives interrupts. The psrset command manages processor sets in Solaris 2.6.
The Load Average
The load average is the sum of the run queue length and the number of jobs currently running on CPUs. The three figures given are averages over the last 1, 5, and 15 minutes. ...