Method of efficient performance monitoring for symetric multi-threading systems

An article comprising:

• a machine accessible medium having a plurality of machine readable instructions, wherein when the instructions are executed by a processor, the instructions provide for sharing of performance monitoring units between multiple execution units by:
• receiving a request from an execution unit to at least one of start and stop performance monitoring operation;
• maintaining a correct sequence of requests to start and stop performance monitoring operation;
• performing arbitration to acquire exclusive execution for one of a plurality of request initiators;
• allocating a request to start performance monitoring operation;
• determining a number of allocated requests to start performance monitoring operation;
• initiating performance monitoring operation;
• removing a request to start performance monitoring operation;
• determining an active mode of performance monitoring operation;
• and
• completing performance monitoring operation.

A system that shares performance monitoring units between multiple execution units comprising:

• logic to receive a request from an execution unit to at least one of start and stop performance monitoring operation;
• logic to maintain a correct sequence of requests to start or stop performance monitoring operation;
• logic to perform arbitration to acquire exclusive execution for one of a plurality of request initiators;
• logic to allocate a request to start performance monitoring operation;
• logic to determine a number of allocated requests to start performance monitoring operation;
• logic to initiate performance monitoring operation;
• logic to remove a request to start performance monitoring operation;
• logic to determine an active mode of performance monitoring operation;
• and
• logic to complete performance monitoring operation.