EXTRACT CPU TIME FACILITY

摘要

An efficient facility for determining resource usage, such as a processor time used by tasks. The determination is performed on behalf of user applications that do not require a call to operating system services. The facility includes an instruction that determines elapsed time and reports it to the user as a single unit of operation.

主权项

1. A computer program product for executing a machine instruction in a processing environment, the processing environment supporting a privileged mode in which both privileged and non-privileged instructions are executable and a non-privileged mode in which only non-privileged instructions are executable, the computer program product comprising:
a computer readable storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising:
obtaining a non-privileged extract CPU time machine instruction to be executed, the non-privileged extract CPU time machine instruction having an operand field that at least partially identifies a memory location to store a central processing unit (CPU) timer value obtained by a privileged instruction; andexecuting the non-privileged extract CPU time machine instruction, said executing comprising:
obtaining the stored CPU timer value from the memory location;obtaining a current CPU timer value from a CPU timer;subtracting the current CPU timer value from the stored CPU timer value; andstoring the result of the subtracting.