mpstat

mpstat

mpstat reports information which is useful in understanding lock contention and CPU loading issues.

mpstat reports the following:

• CPU: Processor ID
• minf: Minor faults
• mjf: Major faults
• xcal: Processor cross-calls (when one CPU wakes up another by interrupting it). If this exceeds 200/second, the application in question may need to be examined.
• intr: Interrupts.
• ithr: Interrupts as threads (except clock).
• csw: Context switches
• icsw: Involuntary context switches (this is probably the more relevant statistic when examining performance issues.)
• migr: Thread migrations to another processor. If the migr measurement of mpstat is greater than 500, rechoose_interval should be sent longer in the kernel.
• smtx: Number of times a CPU failed to obtain a mutex.
• srw: Number of times a CPU failed to obtain a read/write lock on the first try.
• syscl: Number of system calls.
• usr/sys/wt/idl: User/system/wait/idle CPU percentages.