Monitoring Virtual Processor Activity

For information about using monitoring information to tune virtual processors, see the following sections:

View virtual-processor thread information from ISA or execute the following onstat command options.

onstat -g Option: Description
xctl onstat -g sch: Lists the number of semaphore operations, spins, and busy waits for each VP.
xctl onstat -g spi: Lists longspins, which are spin locks that virtual processors have spun more than 10,000 times in order to acquire a lock.
To reduce longspins, reduce the number of virtual processors or reduce the load on the computer. On some platforms, you can use the no-age or processor affinity features.
xctl onstat -g wst: Displays wait statistics.
xctl onstat -g iov: Displays statistics for disk I/O by virtual processor.
The higher the number in the wakeups column, the busier the AIO virtual processors are.
xctl onstat -g glo: Lists global multithreading information.
This listing includes CPU-use information about virtual processors, the total number of sessions, and other multithreading global counters.