Hardware based run-time instrumentation facility for managed run-times

• US 9,483,269 B2
• Filed: 03/05/2013
• Issued: 11/01/2016
• Est. Priority Date: 03/16/2012
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Mitran, Marcel, Shum, Chung-Lung K., Stoodley, Kevin A.
• Primary Examiner(s): Zhen, Wei
• Assistant Examiner(s): HUDA, MOHAMMED NURUL
• Application Number:
  US13/785,089
• Publication Number:
  US 20130246773A1
• Time in Patent Office: 1,337 Days
• Field of Search: 717/130, 717/128, 717/227
• US Class Current: 1/1
• CPC Class Codes: G06F 11/3476 Data logging G06F11/14, G06F11/2205 take precedence
• CPC Class Codes: G06F 11/3644 by instrumenting at runtime
• CPC Class Codes: G06F 17/40 Data acquisition and logging for input to computer G06F3/00
• CPC Class Codes: G06F 2201/865 Monitoring of software
• CPC Class Codes: G06F 9/30058 Conditional branch instructions
• CPC Class Codes: G06F 9/30145 Instruction analysis, e.g. decoding, instruction word fields

Abstract

Embodiments of the invention relate to performing run-time instrumentation. Run-time instrumentation is captured, by a processor, based on an instruction stream of instructions of an application program executing on the processor. The capturing includes storing the run-time instrumentation data in a collection buffer of the processor. A run-time instrumentation sample point trigger is detected by the processor. Contents of the collection buffer are copied into a program buffer as a reporting group based on detecting the run-time instrumentation sample point trigger. The program buffer is located in main storage in an address space that is accessible by the application program.

Claims

1. A computer implemented method for performing run-time instrumentation, the method comprising:

capturing, by a processor, run-time instrumentation data based on an instruction stream of instructions of an application program executing on the processor in one of a supervisor mode and a user mode, the capturing comprising storing the run-time instrumentation data in a collection buffer of the processor that is accessible by the application program when the application program is executing in a supervisor mode and not accessible by the application program when the application program is executing in a user mode;

detecting, by the processor, a run-time instrumentation sample point trigger; and

copying contents of the collection buffer into a program buffer as a reporting group based on the detecting the run-time instrumentation sample point trigger, the program buffer located in main storage in an address space that is accessible by the application program.

2. The method of claim 1, wherein the collection buffer is implemented by hardware located on the processor.

3. The method of claim 1, wherein the capturing and the detecting are performed in a manner that is transparent to the executing.

4. The method of claim 1 further comprising capturing, in the collection buffer, instruction addresses and metadata corresponding to events detected during the executing of the instruction stream.

5. The method of claim 1, wherein the reporting group includes a predetermined number of one or more instrumentation records comprising contents of the collection buffer and system information records.

6. The method of claim 1, wherein the copying includes copying the reporting group into the program buffer starting at a current address of the program buffer, the program buffer stored at a program buffer origin address specified by an instruction accessible control block that also specifies an address of a last byte in the program buffer and the current address in the program buffer.

7. The method of claim 1, wherein the run-time instrumentation sample point trigger includes at least one of executing a sample point instruction, executing at threshold number of instructions, and encountering an elapsed time since a last sample point.

8. The method of claim 1, wherein the run-time instrumentation sample point trigger is a hardware event.

9. The method of claim 1, wherein the run-time instrumentation data includes at least one of a branch taken target address and an emit instruction register value.