TRANSFORMATION OF A PROGRAM-EVENT-RECORDING EVENT INTO A RUN-TIME INSTRUMENTATION EVENT

• US 20130247012A1
• Filed: 03/05/2013
• Published: 09/19/2013
• Est. Priority Date: 03/16/2012
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Gainey, Charles W. Jr., Gschwind, Michael K.
• Granted Patent: US 9,400,736 B2
• Time in Patent Office: Days
• US Class Current: 717/130
• CPC Class Codes: G06F 11/3636 by tracing the execution of the program
• CPC Class Codes: G06F 11/3644 by instrumenting at runtime
• CPC Class Codes: G06F 11/3648 using additional hardware
• CPC Class Codes: G06F 8/31 Programming languages or programming paradigms

Abstract

Embodiments of the invention relate to transforming a program-event-recording event into a run-time instrumentation event. An aspect of the invention includes a method for transforming a program-event-recording event into a run-time instrumentation event. The method includes enabling run-time instrumentation for collecting instrumentation information of an instruction stream executing on a processor. The method also includes detecting, by the processor, a program-event-recording (PER) event, the PER event associated with the instruction stream executing on the processor. The method further includes writing a PER event record to a collection buffer as a run-time instrumentation event based on detecting the PER event, the PER event record identifying the PER event.

Claims

1. A computer implemented method for transforming a program-event-recording event into a run-time instrumentation event, the method comprising:

enabling run-time instrumentation for collecting instrumentation information of an instruction stream executing on a processor;

detecting, by the processor, a program-event-recording (PER) event, the PER event associated with the instruction stream executing on the processor; and

writing a PER event record to a collection buffer as a run-time instrumentation event based on detecting the PER event, the PER event record identifying the PER event.

2. The method of claim 1, wherein detecting the PER event further comprises:

intercepting a PER interruption condition associated with the PER event such that the instruction stream executing on the processor is not interrupted by a PER interruption associated with the PER interruption condition.

3. The method of claim 1, further comprising:

configuring a run-time-instrumentation control based on executing a load run-time instrumentation controls (LRIC) instruction, the LRIC instruction enabling run-time instrumentation PER controls.

4. The method of claim 3, further comprising:

setting a K-bit based on executing the LRIC instruction to grant permission for execution of a modify run-time instrumentation controls (MRIC) instruction to configure run-time instrumentation control values from a lower-privileged program; and

setting a PK-bit based on executing the LRIC instruction to grant permission for execution of the MRIC instruction to configure PER control registers from the lower-privileged program when the run-time instrumentation PER controls are enabled and the K-bit is set.

5. The method of claim 4, wherein the MRIC instruction updates a control block comprising a run-time instrumentation program-buffer current address (RCA) field, a run-time instrumentation program-buffer origin address (ROA) field, and a run-time instrumentation program-buffer limit address (RLA) field, and further comprising:

setting address values in the ROA field and the RLA field to configure a run-time instrumentation program buffer based on the MRIC instruction executed, wherein the PK-bit is clear and the K-bit is set; and

remapping one or more of the RCA field, the ROA field, and the RLA field to configure the PER control registers based on a subsequent MRIC instruction executed, wherein the PK-bit is set and the K-bit is set.

6. The method of claim 3, further comprising:

setting a PI-bit based on executing the LRIC instruction to recognize an instruction causing the PER event as a sample instruction when the run-time instrumentation PER controls are enabled; and

storing a reporting group to a run-time instrumentation program buffer, the reporting group comprising the PER event record and an instruction-type record identifying an instruction causing the PER event as the sample instruction.

7. The method of claim 1, wherein the PER event record comprises:

a PER code identifying the PER event, wherein the PER event is one of;

successful-branching, instruction-fetching, storage-alteration, store-using-real-address, and instruction-fetching nullification;

a PER address-space-control element identification used to translate a reference that caused the PER event;

a PER access identification;

a PER length of an instruction field; and

a PER address containing an instruction address used to fetch the instruction responsible for the PER event.