Run-time-instrumentation controls emit instruction

• US 9,430,238 B2
• Filed: 03/16/2012
• Issued: 08/30/2016
• Est. Priority Date: 03/16/2012
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Stoodley, Kevin A., Gainey, Charles W. Jr., Mitran, Marcel, Shum, Chung-Lung K.
• Primary Examiner(s): Coleman, Eric
• Application Number:
  US13/422,577
• Publication Number:
  US 20130246742A1
• Time in Patent Office: 1,628 Days
• US Class Current: 1/1
• CPC Class Codes: G06F 11/3466 Performance evaluation by tracing or monitoring
• CPC Class Codes: G06F 11/348 Circuit details, i.e. tracer hardware
• CPC Class Codes: G06F 11/3644 by instrumenting at runtime
• CPC Class Codes: G06F 2201/86 Event-based monitoring
• CPC Class Codes: G06F 9/3005 to perform operations for flow control
• CPC Class Codes: G06F 9/30076 to perform miscellaneous control operations, e.g. NOP
• CPC Class Codes: G06F 9/30101 Special purpose registers
• CPC Class Codes: G06F 9/30145 Instruction analysis, e.g. decoding, instruction word fields
• CPC Class Codes: G06F 9/323 for indirect branch instructions
• CPC Class Codes: G06F 9/45504 Abstract machines for programme code execution, e.g. Java virtual machine [JVM], interpreters, emulators

Abstract

Aspects of the invention relate to executing a run-time-instrumentation EMIT (RIEMIT) instruction. A processor is configured to capture the run-time-instrumentation information of a stream of instructions. The RIEMIT instruction is fetched and executed. It is determined if the current run-time-instrumentation controls are configured to permit capturing and storing of run-time-instrumentation information in a run-time-instrumentation program buffer. If the controls are configured to store run-time-instrumentation instructions, then a RIEMIT instruction specified value is stored as an emit record of a reporting group in the run-time-instrumentation program buffer.

Claims

1. A computer program product for executing a run-time-instrumentation controls emit (RIEMIT) instruction, the RIEMIT instruction executable in either a supervisor state or a lesser-privileged state, the computer program product comprising:

a non-transitory tangible storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising;

configuring a processor to capture run-time-instrumentation information of a stream of instructions in a computer program, the configuring including accessing program status word (PSW) associated with the computer program to update a bit in the PSW to indicate that run-time instrumentation data should be captured by the processor, the stream of instructions comprising the RIEMIT instruction, and the computer program is one of a plurality of computer programs for execution by the processor each having an associated PSW;

fetching the RIEMIT instruction;

executing, by the processor, the RIEMIT instruction, the executing comprising;

determining that current run-time-instrumentation controls are configured to permit capturing of run-time-instrumentation information for storing run-time-instrumentation records in a run-time-instrumentation program buffer; and

storing an RIEMIT instruction specified value as an emit record of a reporting group in the run-time-instrumentation program buffer.

2. The computer program product according to claim 1, wherein the reporting group consists of run-time-instrumentation records, the run-time-instrumentation records comprising address reporting (AR) records, each AR record having an instruction address field and an event field, the instruction address field having an instruction address of an instruction associated with a run-time-instrumentation event, the event field having a type value indicating a type of AR record, wherein the emit record is an AR record, wherein, within the reporting group, AR records are arranged, in the reporting group, according to program order of run-time-instrumentation event occurrence associated with an AR record of the reporting group.

3. The computer program product according to claim 1, wherein determining is based on:

an indicator that run-time-instrumentation is enabled;

an indicator that the current run-time-instrumentation controls are valid; and

an indicator that the RIEMIT instruction is enabled.

4. The computer program product according to claim 1, wherein the determining includes any one of:

determining that the RIEMIT instruction is being executed from the lesser-privileged state and that the current run-time-instrumentation controls are configured to allow the execution of the RIEMIT instruction from the lesser-privileged state; and

determining that the RIEMIT instruction is being executed from the supervisor state and that the current run-time-instrumentation controls are configured to allow the execution of the RIEMIT instruction from the supervisor state.

5. The computer program product according to claim 1, wherein the determining comprises determining that the run-time-instrumentation program buffer will accommodate additional data.

6. The computer program product according to claim 1, wherein the RIEMIT instruction comprises a register field for specifying a register location, wherein the RIEMIT instruction specified value is obtained from the register location.

7. The computer program product according to claim 6, further comprising:

capturing run-time-instrumentation information of run-time-instrumentation events in a collection buffer in program order of occurrence of run-time-instrumentation events;

based on the determining, capturing the RIEMIT instruction specified value in the collection buffer in program order; and

storing in the run-time-instrumentation program buffer, information from the collection buffer as records of the reporting group in the run-time-instrumentation program buffer, wherein the reporting group consists of run-time-instrumentation records, the run-time-instrumentation records comprising address reporting (AR) records, each AR record having an instruction address field and an event field, the instruction address field having an instruction address of an instruction associated with a run-time-instrumentation event, the event field having a type field indicating a type of AR record, wherein the emit record is an AR record, wherein, within a reporting group, AR records are arranged, in the reporting group, according to program order of run-time-instrumentation event occurrence associated with an AR record of the reporting group.

8. A computer system for executing a run-time-instrumentation controls emit (RIEMIT) instruction, the RIEMIT instruction executable in either a supervisor state or a lesser-privileged state, the system comprising:

a memory; and

a computer processor comprising a run-time-instrumentation module, the run-time-instrumentation module configured to perform a method comprising;

configuring the computer processor to capture run-time-instrumentation information of a stream of instructions in a computer program, the configuring including accessing a program status word (PSW) associated with the computer program to update a bit in the PSW to indicate that run-time instrumentation data should be captured by the computer processor, the stream of instructions comprising the RIEMIT instruction, and the computer program is one of a plurality of computer programs for execution by the processor each having an associated PSW;

fetching the RIEMIT instruction;

executing the RIEMIT instruction, the executing comprising;

determining current run-time-instrumentation controls are configured to permit capturing of run-time-instrumentation information for storing run-time-instrumentation records in a run-time-instrumentation program buffer; and

storing an RIEMIT instruction specified value as an emit record of a reporting group in the run-time-instrumentation program buffer.

9. The system according to claim 8, wherein the reporting group consists of run-time-instrumentation records, the run-time-instrumentation records comprising address reporting (AR) records, each AR record having an instruction address field and an event field, the instruction address field having an instruction address of an instruction associated with a run-time-instrumentation event, the event field having a type value indicating a type of AR record, wherein the emit record is an AR record, wherein, within the reporting group, AR records are arranged, in the reporting group, according to program order of run-time-instrumentation event occurrence associated with an AR record of the reporting group.

10. The system according to claim 8, wherein determining is based on:

an indicator that run-time-instrumentation is enabled;

an indicator that the current run-time-instrumentation controls are valid; and

an indicator that the RIEMIT instruction is enabled.

11. The system according to claim 8, wherein the determining includes any one of:

determining that the RIEMIT instruction is being executed from the lesser-privileged state and that the current run-time-instrumentation controls are configured to allow the execution of the RIEMIT instruction from the lesser-privileged state; and

determining that the RIEMIT instruction is being executed from the supervisor state and that the current run-time-instrumentation controls are configured to allow the execution of the RIEMIT instruction from the supervisor state.

12. The system according to claim 8, wherein the determining comprises determining that the run-time-instrumentation program buffer will accommodate additional data.

13. The system according to claim 8, wherein the RIEMIT instruction comprises a register field for specifying a register location, wherein the RIEMIT instruction specified value is obtained from the register location.

14. The system according to claim 13, further comprising:

capturing run-time-instrumentation information of run-time-instrumentation events in a collection buffer in program order of occurrence of run-time-instrumentation events;

based on the determining, capturing the RIEMIT instruction specified value in the collection buffer in program order; and

storing in the run-time-instrumentation program buffer, information from the collection buffer as records of the reporting group in the run-time-instrumentation program buffer, wherein the reporting group consists of run-time-instrumentation records, the run-time-instrumentation records comprising address reporting (AR) records, each AR record having an instruction address field and an event field, the instruction address field having an instruction address of an instruction associated with a run-time-instrumentation event, the event field having a type field indicating a type of AR record, wherein the emit record is an AR record, wherein, within a reporting group, AR records are arranged, in the reporting group, according to program order of run-time-instrumentation event occurrence associated with an AR record of the reporting group.