Virtualizing precise event based sampling

• Main Authors: Kleen, Andreas, Strong, Beeman C, Chynoweth, Michael W, Weier, Kimberly C, Merten, Matthew C, Brandt, Jason W, Abraham, Seth, Zhou, Grant G, Schmid, Angela D, Yasin, Ahmad, Bratanov, Stanislav
• Format: Patent
• Language: English
• Published: 06.07.2021
• Subjects: CALCULATING; COMPUTING; COUNTING; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRIC DIGITAL DATA PROCESSING; ELECTRICITY; PHYSICS; TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHICCOMMUNICATION

A processor is to execute and retire instructions for a virtual machine. A reload register is coupled to the core is to store a reload value. A performance monitoring counter (PMC) register is coupled to the reload register and an event-based sampler operatively is coupled to the reload register and the PMC register. The event-based sampler includes circuitry to load the reload value into the PMC register and increment the PMC register after detecting each occurrence of an event of a certain type as a result of execution of the instructions. Upon detecting an occurrence of the event after the PMC register reaches a predetermined trigger value, the event-based sampler is to execute microcode to generate field data for elements within a sampling record, wherein the field data relates to a current processor state of execution, and reload the reload value from the reload register into the PMC register.