User Guide

Intel® VTune™ Profiler User Guide

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ID 766319
Date 11/07/2023
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Document Table of Contents
Document Table of Contents x
Intel® VTune™ Profiler User Guide
Intel® VTune™ Profiler User Guide x
Introduction Install Intel® VTune™ Profiler Open Intel® VTune™ Profiler Set Up Project Set Up Analysis Target Analyze Performance Intel® VTune™ Profiler Command Line Interface API Support Troubleshooting Reference Notices and Disclaimers
Introduction x
Tuning Methodology Tutorials and Samples Notational Conventions Get Help Product Website and Support Related Information
Install Intel® VTune™ Profiler x
Sampling Drivers Set Up System for GPU Analysis Verify Intel® VTune™ Profiler Installation Install VTune Profiler Server Security Best Practices
Set Up System for GPU Analysis x
Rebuild and Install the Kernel for GPU Analysis Rebuild and Install Module i915 for GPU Analysis on CentOS* Rebuild and Install Module i915 for GPU Analysis on Ubuntu*
Install VTune Profiler Server x
Set Up Transport Security Configure User Authentication/Authorization
Open Intel® VTune™ Profiler x
Get Started with Intel® VTune™ Profiler Intel® VTune™ Profiler Graphical User Interface Web Server Interface Microsoft Visual Studio* Integration Eclipse* and Intel System Studio IDE Integration Containerization Support macOS* Support
Containerization Support x
Run VTune Profiler in a Container Profile Container Targets from the Host
Set Up Project x
WHERE: Analysis System WHAT: Analysis Target HOW: Analysis Types Search Directories
WHERE: Analysis System x
Analysis System Options
WHAT: Analysis Target x
Analysis Target Options
Search Directories x
Search Order
Set Up Analysis Target x
Prepare Application for Analysis Windows* Targets Linux* Targets Embedded Linux* Targets FreeBSD* Targets QNX* Targets Managed Code Targets Android* Targets Intel® Xeon Phi™ Processor Targets Targets in Virtualized Environments Targets in a Cloud Environment Arbitrary Targets Embedded System Targets
Windows* Targets x
Install the Sampling Drivers for Windows* Targets Debug Information for Windows* Application Binaries Compiler Switches for Performance Analysis on Windows* Targets Debug Information for Windows* System Libraries Add Administrative Privileges
Linux* Targets x
Build and Install the Sampling Drivers for Linux* Targets Debug Information for Linux* Application Binaries Compiler Switches for Performance Analysis on Linux* Targets Enable Linux* Kernel Analysis Resolution of Symbol Names for Linux-Loadable Kernel Modules Analyze Statically Linked Binaries on Linux* Targets Set Up Remote Linux* Target
Set Up Remote Linux* Target x
Set Up Linux* System for Remote Analysis Configure SSH Access for Remote Collection Search Directories for Remote Linux* Targets Temporary Directory for Performance Results on Linux* Targets
Embedded Linux* Targets x
Configure Yocto Project* and VTune Profiler with the Integration Layer Configure Yocto Project*/Wind River* Linux* and Intel® VTune™ Profiler with the Intel System Studio Integration Layer Configure Yocto Project* and Intel® VTune™ Profiler with the Linux* Target Package
FreeBSD* Targets x
Set Up FreeBSD* System
Managed Code Targets x
.NET* Targets Windows Store Application Targets Go* Application Targets
Android* Targets x
Build and Install Sampling Drivers for Android* Targets Set Up Android* System Enable Java* Analysis on Android* System Prepare an Android* Application for Analysis Analyze Unplugged Devices Search Directories for Android* Targets
Targets in Virtualized Environments x
Profile Targets on a VMware* Guest System Profile Targets on a Parallels* Guest System Profile Targets on a KVM* Guest System Profile Targets on a Xen* Virtualization Platform Profile Targets in the Hyper-V* Environment
Profile Targets on a KVM* Guest System x
Profile KVM Kernel Modules from the Host Profile KVM Kernel and User Space on the KVM System Profile KVM Kernel and User Space from the Host
Analyze Performance x
User-Mode Sampling and Tracing Collection Hardware Event-based Sampling Collection Performance Snapshot Algorithm Group Microarchitecture Analysis Group Parallelism Analysis Group Input and Output Analysis Accelerators Analysis Group Platform Analysis Group Platform Analysis Hybrid CPU Analysis Source Code Analysis Custom Analysis Energy Analysis Code Profiling Scenarios Control Data Collection Manage Data Views Manage Result Files
Hardware Event-based Sampling Collection x
Allow Multiple Runs or Multiplex Events Hardware Event-based Sampling Collection with Stacks
Algorithm Group x
Hotspots Analysis for CPU Usage Issues Anomaly Detection Analysis (preview) Memory Consumption Analysis
Hotspots Analysis for CPU Usage Issues x
Hotspots View
Anomaly Detection Analysis (preview) x
Anomaly Detection View
Memory Consumption Analysis x
Memory Consumption and Allocations View
Microarchitecture Analysis Group x
Microarchitecture Exploration Analysis for Hardware Issues Memory Access Analysis for Cache Misses and High Bandwidth Issues
Microarchitecture Exploration Analysis for Hardware Issues x
Microarchitecture Exploration View Microarchitecture Pipe
Memory Access Analysis for Cache Misses and High Bandwidth Issues x
Memory Usage View
Parallelism Analysis Group x
Threading Analysis HPC Performance Characterization Analysis
Threading Analysis x
Threading Efficiency View
HPC Performance Characterization Analysis x
HPC Performance Characterization View
Input and Output Analysis x
Analyze Platform Performance Analyze DPDK Applications Analyze SPDK Applications Analyze Linux Kernel I/O
Accelerators Analysis Group x
GPU Offload Analysis GPU Compute/Media Hotspots Analysis (Preview) CPU/FPGA Interaction Analysis NPU Exploration Analysis (Preview)
GPU Compute/Media Hotspots Analysis (Preview) x
GPU Compute/Media Hotspots View
CPU/FPGA Interaction Analysis x
CPU/FPGA Interaction View
NPU Exploration Analysis (Preview) x
NPU Exploration View
Platform Analysis Group x
System Overview Analysis
System Overview Analysis x
Analyze Interrupts Analyze Latency Issues
Custom Analysis x
Custom Analysis Options
Custom Analysis Options x
Highly Accurate CPU Time Data Collection Hardware Event List Linux* and Android* Kernel Analysis Sampling Interval Sample After Value
Hardware Event List x
Hardware Event Skid Instructions Retired Event Precise Events
Energy Analysis x
Run Energy Analysis View Energy Analysis Data with Intel® VTune™ Profiler Interpret Energy Analysis Data with Intel® VTune™ Profiler
Code Profiling Scenarios x
Java* Code Analysis Python* Code Analysis Intel® Threading Building Blocks Code Analysis MPI Code Analysis OpenSHMEM* Code Analysis with Fabric Profiler GPU Application Analysis on Intel® HD Graphics and Intel® Iris® Graphics Frame Data Analysis Task Analysis
GPU Application Analysis on Intel® HD Graphics and Intel® Iris® Graphics x
GPU OpenCL™ Application Analysis Intel® Media SDK Program Analysis
Control Data Collection x
Finalization Pause Data Collection Limit Data Collection Generate Command Line Configuration from GUI Minimize Collection Overhead Import External Data
Import External Data x
Use a Custom Collector Create a CSV File with External Data Import Linux Perf* Trace with VTune Profiler Metrics Examples of CSV Format and Imported Data
Manage Data Views x
Switch Viewpoints Control Window Synchronization View Stacks Manage Grid Views Manage Timeline View Change Threshold Values Choose Data Format Group and Filter Data View Data on Inline Functions Analyze Loops Stitch Stacks for Intel® oneAPI Threading Building Blocks or OpenMP* Analysis Search for Data
View Stacks x
Call Stack Mode Metrics Distribution Over Call Stacks
Manage Result Files x
VTune Profiler Filenames and Locations Import Results and Traces into VTune Profiler GUI Compare Results
Compare Results x
Compare Source Code View Comparison Data
View Comparison Data x
Comparison Summary Bottom-up Comparison Top-down Tree Comparison
Intel® VTune™ Profiler Command Line Interface x
vtune Command Syntax vtune Actions Run Command Line Analysis Work with Results from Command Line Generate Command Line Reports Command Line Usage Scenarios Command Line Interface Reference Report Problems from Command Line
Run Command Line Analysis x
performance-snapshot Command Line Analysis hotspots Command Line Analysis anomaly-detection Command Line Analysis threading Command Line Analysis memory-consumption Command Line Analysis hpc-performance Command Line Analysis uarch-exploration Command Line Analysis memory-access Command Line Analysis tsx-exploration Command Line Analysis tsx-hotspots Command Line Analysis sgx-hotspots Command Line Analysis gpu-hotspots Command Line Analysis gpu-offload Command Line Analysis npu graphics-rendering Command Line Analysis fpga-interaction Command Line Analysis io Command Line Analysis system-overview Command Line Analysis runsa/runss Custom Command Line Analysis Configure Analysis Options from Command Line
Configure Analysis Options from Command Line x
Collect System-Wide Data from Command Line Collect Data on Remote Linux* Systems from Command Line Configure GPU Analysis from Command Line Specify Search Directories from Command Line Specify Result Directory from Command Line Pause Collection from Command Line Manage Analysis Duration from Command Line Limit Data Collection from Command Line
Work with Results from Command Line x
View Command Line Results in the GUI Import Results from Command Line Re-finalize Results from Command Line
Generate Command Line Reports x
Summary Report Hotspots Report Hardware Events Report Callstacks Report Timeline Report Top-down Report gprof-cc Report Difference Report View Source Objects from Command Line Save and Format Command Line Reports Filter and Group Command Line Reports
Command Line Usage Scenarios x
Use VTune Profiler Server in Containers Android* Target Analysis from the Command Line OpenMP* Analysis from the Command Line Java* Code Analysis from the Command Line Configure Java Collection Examples View Summary Report Identify Hottest Methods Analyze Stacks Analyze Hardware Metrics Limitations See Also
Command Line Interface Reference x
Option Descriptions and General Rules allow-multiple-runs analyze-kvm-guest analyze-system app-working-dir archive call-stack-mode collect collect-with column command cpu-mask csv-delimiter cumulative-threshold-percent custom-collector data-limit discard-raw-data duration filter finalization-mode finalize format group-by help import inline-mode knob kvm-guest-kallsyms kvm-guest-modules limit loop-mode mrte-mode no-follow-child no-summary no-unplugged-mode quiet report report-knob report-output report-width result-dir resume-after return-app-exitcode ring-buffer search-dir show-as sort-asc sort-desc source-object source-search-dir stack-size start-paused strategy target-install-dir target-system target-tmp-dir target-duration-type target-pid target-process time-filter trace-mpi user-data-dir verbose version
API Support x
Instrumentation and Tracing Technology APIs JIT Profiling API System APIs Supported by Intel® VTune™ Profiler
Instrumentation and Tracing Technology APIs x
Basic Usage and Configuration Instrumentation and Tracing Technology API Reference
Basic Usage and Configuration x
Configure Your Build System Attach ITT APIs to a Launched Application Instrument Your Application Minimize ITT API Overhead View Instrumentation and Tracing Technology (ITT) API Task Data in Intel® VTune™ Profiler
Instrumentation and Tracing Technology API Reference x
Domain API String Handle API Collection Control API Thread Naming API Task API Frame API Histogram API User-Defined Synchronization API Event API Counter API Context Metadata API Load Module API Memory Allocation APIs
JIT Profiling API x
Using JIT Profiling API JIT Profiling API Reference
JIT Profiling API Reference x
iJIT_NotifyEvent iJIT_IsProfilingActive iJIT_ GetNewMethodID
Troubleshooting x
Best Practices: Resolve Intel® VTune™ Profiler BSODs, Crashes, and Hangs in Windows* OS Error Message: Application Sets Its Own Handler for Signal Error Message: Cannot Enable Event-Based Sampling Collection Error Message: Cannot Collect GPU Hardware Metrics Error Message: Cannot Load Data File Error Message: Cannot Locate Debugging Information Error Message: Cannot Open Data Error Message: Client Is Not Authorized to Connect to Server Error Message: Root Privileges Required for Processor Graphics Events Error Message: No Pre-built Driver Exists for This System Error Message: Not All OpenCL™ API Profiling Callbacks Are Received Error Message: Problem Accessing the Sampling Driver Error Message: Required Key Not Available Error Message: Scope of ptrace System Call Is Limited Error Message: Stack Size Is Too Small Error Message: Symbol File Is Not Found Problem: Analysis of the .NET* Application Fails Problem: Cannot Access VTune Profiler Documentation Problem: CPU time for Hotspots or Threading Analysis is Too Low Problem: 'Events= Sample After Value (SAV) * Samples' Is Not True If Multiple Runs Are Disabled Problem: Guessed Stack Frames Problem: GUI Hangs or Crashes Problem: Inaccurate Sum in the Grid Problem: Information Collected via ITT API Is Not Available When Attaching to a Process Problem: No GPU Utilization Data Is Collected Problem: Same Functions Are Compared As Different Instances Problem: Skipped Stack Frames Problem: Stack in the Top-Down Tree Window Is Incorrect Problem: Stacks in Call Stack and Bottom-Up Panes Are Different Problem: System Functions Appear in the User Functions Only Mode Problem: VTune Profiler is Slow to Respond When Collecting or Displaying Data Problem: VTune Profiler is Slow on X-Servers with SSH Connection Problem: Unexpected Paused Time Problem: {Unknown Timer} in the Platform Power Analysis Viewpoint Problem: Unknown Critical Error Due to Disabled Loopback Interface Problem: Unknown Frames Problem: Unreadable Text on macOS* Problem: Unsupported Microsoft* Windows* OS Warnings about Accurate CPU Time Collection
Reference x
User Interface Reference CPU Metrics Reference GPU Metrics Reference OpenCL™ Kernel Analysis Metrics Reference Energy Analysis Metrics Reference Intel Processor Events Reference
User Interface Reference x
Context Menu: Grid Context Menus: Call Stack Pane Context Menus: Project Navigator Context Menus: Source/Assembly Window Dialog Box: Binary/Symbol Search Dialog Box: Source Search Hot Keys Menu: Customize Grouping Menu: Intel VTune Profiler Pane: Call Stack Pane: Options - General Pane: Options - Result Location Pane: Options - Source/Assembly Project Navigator Pane: Timeline Toolbar: Configure Analysis Toolbar: Filter Toolbar: Source/Assembly Toolbar: Intel VTune Profiler Window: Bandwidth - Platform Power Analysis Window: Bottom-up Window: Caller/Callee Window: Cannot Find <file type> File Window: Collection Log Window: Compare Results Window: Configure Analysis Window: Core Wake-ups - Platform Power Analysis Window: Correlate Metrics - Platform Power Analysis Window: CPU C/P States - Platform Power Analysis Window: Debug Window: Event Count - Hardware Events Window: Flame Graph Window: Graphics - GPU Compute/Media Hotspots Window: Graphics C/P States - Platform Power Analysis Window: NC Device States - Platform Power Analysis Window: Platform Window: Platform Power Analysis Window: Sample Count - Hardware Events Window: SC Device States - Platform Power Analysis Window: Summary Window: System Sleep States - Platform Power Analysis Window: Temperature/Thermal Sample - Platform Power Analysis Window: Timer Resolution - Platform Power Analysis Window: Top-down Tree Window: Uncore Event Count - Hardware Events Window: Wakelocks - Platform Power Analysis
Window: Summary x
Window: Summary - Input and Output Summary Window: Summary - Microarchitecture Exploration Window: Summary - GPU Analysis Window: Summary - Hardware Events Window: Summary - Hotspots by CPU Utilization Window: Summary - HPC Performance Characterization Window: Summary - Memory Consumption Window: Summary - Memory Usage Window: Summary - Platform Power Analysis
GPU Metrics Reference x
ALU0 Active ALU0 Instructions ALU1 Active ALU1 Instructions ALU2 Active ALU2 Instructions ALU0 and ALU1 Active ALU0 and ALU2 Active Average Time Computing Threads Started Computing Threads Started, Threads/sec CPU Time EU 2 FPU Pipelines Active EU Array Active EU Array Idle EU Array Stalled/Idle EU Array Stalled EU IPC Rate EU Send pipeline active EU Threads Occupancy Host to GPU Memory Read Bandwidth Host-to-GPU Memory Write Bandwidth Global GPU EU Array Usage GPU L3 Bound GPU L3 Miss Ratio GPU L3 Misses GPU L3 Misses, Misses/sec GPU Memory Read Bandwidth, GB/sec GPU Memory Texture Read Bandwidth, GB/sec GPU Memory Write Bandwidth, GB/sec GPU Texel Quads Count, Count/sec GPU Utilization Instance Count L3 Read Bandwidth L3 Write Bandwidth L3 Sampler Bandwidth, GB/sec L3 Shader Bandwidth, GB/sec LLC Miss Rate due GPU Lookups LLC Miss Ratio due GPU Lookups Local Maximum GPU Utilization Occupancy PS EU Active % PS EU Stall % Ratio to Max Bandwidth, % Ratio to Max Bandwidth, % Ratio to Max Bandwidth, % Render/GPGPU Command Streamer Loaded Samples Blended Samples Killed in PS, pixels Samples Written Sampler Busy Sampler Is Bottleneck Shared Local Memory Read Bandwidth, GB/sec Shared Local Memory Write Bandwidth, GB/sec SIMD Width Stack-to-stack Incoming Bandwidth Stack-to-stack Outgoing Bandwidth System Memory Read Bandwidth System Memory Write Bandwidth Size Total, GB/sec Total Time Typed Memory Read Bandwidth, GB/sec Typed Memory Write Bandwidth, GB/sec Typed Reads Coalescence Typed Writes Coalescence Untyped Memory Read Bandwidth, GB/sec Untyped Memory Write Bandwidth, GB/sec Untyped Reads Coalescence Untyped Writes Coalescence VS EU Active VS EU Stall
OpenCL™ Kernel Analysis Metrics Reference x
Computing Task Total Time Instance Count SIMD Width SIMD Utilization Work Size
Energy Analysis Metrics Reference x
Available Core Time C-State D0ix States DRAM Self Refresh Energy Consumed (mJ) Idle Wake-ups P-State S0ix States Temperature Timer Resolution Total Time in C0 State Total Time in Non-C0 States Total Time in S0 State Total Wake-up Count Wake-ups Wake-ups/sec per Core
Intel® VTune™ Profiler User Guide

Java* Code Analysis from the Command Line

Intel® VTune™ Profiler provides a low-overhead user-mode sampling and tracing and hardware event-based sampling analysis of the JIT compiled code executed with Oracle* JDK or OpenJDK*. The analysis of the interpreted Java methods is limited.

You may use the hardware event-based sampling data collection that monitors hardware events in the CPU's pipeline and can identify coding pitfalls limiting the most effective execution of instructions in the CPU. The hardware performance metrics are available and can be displayed against the application modules, functions, and Java code source lines. You may also run the hardware event-based sampling collection with stacks when you need to find out a call path for a function called in a driver or middleware layer in your system.

Configure Java Collection

Use the following syntax to configure Java analysis from the command line:

vtune -collect <analysis_type> [-[no-]follow-child] [-mrte-mode=<mrte_mode_value>] [<-knob> <knob_name=knob_option>] [--] <target>

where

  • <analysis_type> is the type of analysis to run
  • -[no-]follow-child is an action option to collect data on the processes spawned by the target process. It is recommended to enable the option for applications launched by a script. The option is enabled by default.
  • <mrte_mode_value> is a profiling mode for the managed code. The auto mode is enabled by default.
  • <-knob> is an option that configures the analysis
  • [knobName=knobValue] is the name of the specified knob and its value
  • <target> is the path and name of the application to analyze
NOTE:

To see all knobs available for a predefined analysis type, enter:

vtune -help collect <analysis_type>

To see knobs for a custom analysis type, enter:

vtune -help collect-with <analysis_type>

Examples

Example 1: Running Java Analysis

The following command line runs the Hotspots analysis on a java command on Linux*: 

vtune -collect hotspots -- java -Xcomp -Djava.library.path=native_lib/ia32 -cp /home/Design/Java/mixed_call MixedCall 3 2

Example 2: Running Analysis for Embedded Java Command

You may embed your java command in a batch file or executable script before running the analysis. For example, on Windows* create a run.bat file with the following command: 

java.exe -Xcomp -Djava.library.path=native_lib\ia32 -cp C:\Design\Java\mixed_call MixedCall 3 1

The following command line runs the Hotspots analysis on a specified batch file with embedded java command: 

vtune -collect hotspots -- run.bat

Example 3: Attaching Analysis to Java Process

In case your Java application needs to run for some time or cannot be launched at the start of this analysis, you may attach the VTune Profiler to the Java process. To do this, specify the following analysis target: --target-process java.

NOTE:

The dynamic attach mechanism is supported only with the Java Development Kit (JDK).

The following example attaches the Hotspots analysis to a running Java process on Linux: 

vtune -collect hotspots --target-process java

View Summary Report

VTune Profiler automatically generates the summary report when data collection completes. Similar to the Summary window, available in GUI, the command line report provides overall performance data of your Java target.

NOTE:

For more information on analyzing the summary report data, refer to the Summary Report section.

Examples

The following example generates the summary report for the Hotspots analysis result. For user-mode sampling and tracing analysis results, the summary report includes Collection and Platform information, CPU information and summary per the basic metrics.

On Windows: 


Collection and Platform Info
----------------------------
Parameter                 r001hs

------------------------  ------------------------------------------
Operating System          Microsoft Windows 10
Result Size               21258782
Collection start time     11:58:36 15/04/2019 UTC
Collection stop time      11:58:50 15/04/2019 UTC

CPU
---
Parameter          r001hs
-----------------  -------------------------------------------------
Name               4th generation Intel(R) Core(TM) Processor family
Frequency          2494227391
Logical CPU Count  4

Summary
-------
Elapsed Time:       12.939
CPU Time:           14.813
Average CPU Usage:  1.012

On Linux: 

Collection and Platform Info
----------------------------
Parameter                 r002hs
-------------------------------------------------------------------
Application Command Line  /tmp/java_mixed_call/src/run.sh

Operating System          3.16.0-30-generic NAME="Ubuntu"
VERSION="14.04.2 LTS, Trusty Tahr"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 14.04.2 LTS"
VERSION_ID="14.04"
HOME_URL="http://www.ubuntu.com/"
SUPPORT_URL="http://help.ubuntu.com/"
BUG_REPORT_URL="http://bugs.launchpad.net/ubuntu/"
Computer Name             10.125.21.55

Result Size               11560723

Collection start time     13:55:00 05/02/2019 UTC

Collection stop time      13:55:10 05/02/2019 UTC


CPU
---
Parameter          r001hs
-----------------  -------------------------------------------------
Name               3rd generation Intel(R) Core(TM) Processor family
Frequency          3492067692
Logical CPU Count  8

Summary
-------
Elapsed Time:       10.183
CPU Time:           19.200
Average CPU Usage:  1.885

This example generates the summary report for the Hotspots analysis (hardware event-based sampling mode) result. For hardware event-based sampling analysis results, the summary report includes Collection and Platform information, CPU information, summary per the basic metrics, and an event summary. 

Collection and Platform Info
----------------------------
Parameter                 r002hs

------------------------  ------------------------------------------
Operating System          3.16.0-30-generic NAME="Ubuntu"
VERSION="14.04.2 LTS, Trusty Tahr"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 14.04.2 LTS"
VERSION_ID="14.04"
HOME_URL="http://www.ubuntu.com/"
SUPPORT_URL="http://help.ubuntu.com/"
BUG_REPORT_URL="http://bugs.launchpad.net/ubuntu/"
Result Size               171662827
Collection start time     10:44:34 15/04/2019 UTC
Collection stop time      10:44:50 15/04/2019 UTC

CPU
---
Parameter          r002hs
-----------------  -------------------------------------------------
Name               4th generation Intel(R) Core(TM) Processor family
Frequency          2494227445
Logical CPU Count  4

Summary
-------
Elapsed Time:       15.463
CPU Time:           6.392
Average CPU Usage:  0.379
CPI Rate:           1.318

Event summary
-------------
Hardware Event Type         Hardware Event Count:Self  Hardware Event Sample Count:Self  Events Per Sample
--------------------------  -------------------------  --------------------------------  -----------------
INST_RETIRED.ANY                          13014608235                              8276  1900000
CPU_CLK_UNHALTED.THREAD                   17158609921                              8207  1900000
CPU_CLK_UNHALTED.REF_TSC                  15942400300                              5163  1900000
BR_INST_RETIRED.NEAR_TAKEN                 1228364727                              4648  200003
CALL_COUNT                                  213650621                             75413  1
ITERATION_COUNT                             370567815                             84737  1
LOOP_ENTRY_COUNT                            162943310                             70069  1

Identify Hottest Methods

Use the hotspots command line report as a starting point for identifying program units (for example: functions, modules, or objects) that take the most processor time (Hotspots analysis), underutilize available CPUs or have long waits (Threading analysis), and so on.

The report displays the hottest program units in the descending order by default, starting from the most performance-critical unit. The command-line reports provide the same data that is displayed in the default GUI analysis viewpoints.

NOTE:
  • To display a list of available groupings for a hotspots report, enter: vtune -report hotspots -r <result_dir> group-by=?.
  • To set the number of top items to include in a report, use the limit action option: vtune -report <report_type> -limit <value> -r <result_dir>

Examples

This example generates the hotspots report for the Hotspots analysis result and groups the data by module. The result file is not specified and VTune Profiler uses the latest analysis result. 

vtune -report hotspots

On Windows: 


Function               CPU Time  CPU Time:Effective Time  CPU Time:Effective Time:Idle  CPU Time:Effective Time:Poor  CPU Time:Effective Time:Ok  CPU Time:Effective Time:Ideal  CPU Time:Effective Time:Over  CPU Time:Spin Time  CPU Time:Overhead Time  Module          Function (Full)        Source File   Start Address
---------------------  --------  -----------------------  ----------------------------  ----------------------------  --------------------------  -----------------------------  ----------------------------  
consume_time            10.371s                  10.371s                            0s                       10.341s                      0.020s                         0.010s                            0s                  0s                      0s  mixed_call.dll  consume_time           mixed_call.c  0x180001000  
NtWaitForSingleObject    1.609s                       0s                            0s                            0s                          0s                             0s                            0s              1.609s                      0s  ntdll.dll       NtWaitForSingleObject  [Unknown]     0x1800906f0  
WriteFile                0.245s                   0.245s                        0.009s                        0.190s                      0.030s                         0.016s                            0s                  0s                      0s  KERNELBASE.dll  WriteFile              [Unknown]     0x180001c50  
func@0x707d5440          0.114s                   0.010s                            0s                        0.010s                          0s                             0s                            0s              0.104s                      0s  jvm.dll         func@0x707d5440        [Unknown]     0x707d5440   
func@0x705be5c0          0.072s                   0.025s                            0s                        0.025s                          0s                             0s                            0s              0.047s                      0s  jvm.dll         func@0x705be5c0        [Unknown]     0x705be5c0   
...

On Linux: 


Function            CPU Time  CPU Time:Effective Time  CPU Time:Effective Time:Idle  CPU Time:Effective Time:Poor  CPU Time:Effective Time:Ok  CPU Time:Effective Time:Ideal  CPU Time:Effective Time:Over  CPU Time:Spin Time  CPU Time:Overhead Time  Module            Function (Full)     Source File  Start Address
------------------  --------  -----------------------  ----------------------------  ----------------------------  --------------------------  -----------------------------  ----------------------------  
[libmixed_call.so]   17.180s                  17.180s                            0s                       17.180s                          0s                             0s                            0s                  0s                      0s  libmixed_call.so  [libmixed_call.so]  [Unknown]    0

[libjvm.so]           1.698s                   1.698s                        0.020s                        1.678s                          0s                             0s                            0s                  0s                      0s  libjvm.so         [libjvm.so]         [Unknown]    0

[libpthread.so.0]     0.136s                   0.136s                            0s                        0.136s                          0s                             0s                            0s                  0s                      0s  libpthread.so.0   [libpthread.so.0]   [Unknown]    0

[libtpsstool.so]      0.052s                   0.052s                            0s                        0.052s                          0s                             0s                            0s                  0s                      0s  libtpsstool.so    [libtpsstool.so]    [Unknown]    0
...

The following example generates the hotspots report for the specified Hotspots analysis result (hardware event-based sampling mode), sets the number of items to include in the report to 3, and groups the report data by application module. 

vtune -report hotspots -limit 3 -r r002hs -group-by module

On Windows: 


Module          CPU Time  CPU Time:Effective Time  CPU Time:Effective Time:Idle  CPU Time:Effective Time:Poor  CPU Time:Effective Time:Ok  CPU Time:Effective Time:Ideal  CPU Time:Effective Time:Over  CPU Time:Spin Time  CPU Time:Overhead Time  Instructions Retired  CPI Rate  Wait Rate  CPU Frequency Ratio  Context Switch Time  Context Switch Time:Wait Time  Context Switch Time:Inactive Time  Context Switch Count  Context Switch Count:Preemption  Context Switch Count:Synchronization  Module Path                                                                                 
--------------  --------  -----------------------  ----------------------------  ----------------------------  --------------------------  -----------------------------  ----------------------------  -------
mixed_call.dll   15.294s                  15.294s                        0.419s                       14.871s                      0.004s                             0s                            0s                  0s                      0s        21,148,958,284     1.907      0.000                1.149               1.401s                             0s                             1.401s                26,769                           26,769                                     0  C:\work\module Java\module Java\java_mixed_call\vc9\bin32\mixed_call.dll
jvm.dll           0.582s                   0.582s                        0.033s                        0.547s                      0.002s                             0s                            0s                  0s                      0s           792,807,896     1.513      0.437                0.899               0.047s                         0.005s                             0.042s                   462                              451                                    11  C:\Program Files (x86)\Java\jre8\bin\client\jvm.dll                                         
ntoskrnl.exe      0.404s                   0.404s                        0.034s                        0.370s                      0.001s                             0s                            0s                  0s                      0s           660,557,183     1.096      0.000                0.780                                                                                                                                                                                      C:\WINDOWS\system32\ntoskrnl.exe                                                            
...

On Linux: 


Module            CPU Time  CPU Time:Effective Time  CPU Time:Effective Time:Idle  CPU Time:Effective Time:Poor  CPU Time:Effective Time:Ok  CPU Time:Effective Time:Ideal  CPU Time:Effective Time:Over  CPU Time:Spin Time  CPU Time:Overhead Time  Instructions Retired  CPI Rate  Wait Rate  CPU Frequency Ratio  Context Switch Time  Context Switch Time:Wait Time  Context Switch Time:Inactive Time  Context Switch Count  Context Switch Count:Preemption  Context Switch Count:Synchronization  Module Path                                                                                 
----------------  --------  -----------------------  ----------------------------  ----------------------------  --------------------------  -----------------------------  ----------------------------  ------
libmixed_call.so   15.294s                  15.294s                        0.419s                       14.871s                      0.004s                             0s                            0s                  0s                      0s        21,148,958,284     1.907      0.000                1.149               1.401s                             0s                             1.401s                26,769                           26,769                                     0  /tmp/java_mixed_call/src/libmixed_call.so
libjvm.so           0.582s                   0.582s                        0.033s                        0.547s                      0.002s                             0s                            0s                  0s                      0s           792,807,896     1.513      0.437                0.899               0.047s                         0.005s                             0.042s                   462                              451                                       11  /tmp/java_mixed_call/src/libmjvm.so                                         
...                                                    
...

Analyze Stacks

To get the maximum performance out of your Java application, writing and compiling performance critical modules of your Java project in native languages, such as C or even assembly. This will help your application take advantage of vectorization and make complete use of powerful CPU resources. This way of programming helps to employ powerful CPU resources like vector computing (implemented via SIMD units and instruction sets). In this case, compute-intensive functions become hotspots in the profiling results, which is expected as they do most of the job. However, you might be interested not only in hotspot functions, but in identifying locations in Java code these functions were called from via a JNI interface. Tracing such cross-runtime calls in the mixed language algorithm implementations could be a challenge.

Use the callstacks report to display full stack data for each hotspot function and identify the impact of each stack on the function CPU or Wait time.

NOTE:

To display a list of available groupings for a callstacks report, enter vtune -report callstacks -r <result_dir> group-by=?.

Example

The following command line generates the callstacks report for the specified Hotspots analysis result.

On Windows: 


Function      Function Stack             CPU Time  Module                Function (Full)                 Source File     Start Address
------------  -------------------------  --------  --------------------  ------------------------------  --------------  -------------
consume_time                              10.371s  mixed_call.dll        consume_time                    mixed_call.c    0x180001000
              MixedCall::CallNativeFunc   10.371s  [Compiled Java code]  MixedCall::CallNativeFunc(int)  MixedCall.java  0x186debc0
              MixedCall::foo4                  0s  [Compiled Java code]  MixedCall::foo4(int)            MixedCall.java  0x186c1ae3
              MixedCall::foo3                  0s  [Compiled Java code]  MixedCall::foo3(int)            MixedCall.java  0x186bb583
              MixedCall::foo2                  0s  [Compiled Java code]  MixedCall::foo2(int)            MixedCall.java  0x186bb583
              MixedCall::foo1                  0s  [Compiled Java code]  MixedCall::foo1(int)            MixedCall.java  0x186bb583
              MixedCall::run                   0s  [Compiled Java code]  MixedCall::run()                MixedCall.java  0x186bb19d
              call_stub                        0s  [Dynamic code]        call_stub                       [Unknown]       0x18010827
...

On Linux: 


Function            Function Stack             CPU Time  Module                Function (Full)                 Source File     Start Address
------------------  -------------------------  --------  --------------------  ------------------------------  --------------  --------------
[libmixed_call.so]                              17.180s  libmixed_call.so      [libmixed_call.so]              [Unknown]       0
                    [libmixed_call.so]           8.600s  libmixed_call.so      [libmixed_call.so]              [Unknown]       0
                    MixedCall::CallNativeFunc        0s  [Compiled Java code]  MixedCall::CallNativeFunc(int)  MixedCall.java  0x7fb63937eec0
                    MixedCall::foo4                  0s  [Compiled Java code]  MixedCall::foo4(int)            MixedCall.java  0x7fb6393831e3
                    MixedCall::foo3                  0s  [Compiled Java code]  MixedCall::foo3(int)            MixedCall.java  0x7fb63938046c
                    MixedCall::foo2                  0s  [Compiled Java code]  MixedCall::foo2(int)            MixedCall.java  0x7fb63938046c
                    MixedCall::foo1                  0s  [Compiled Java code]  MixedCall::foo1(int)            MixedCall.java  0x7fb63938046c
                    MixedCall::run                   0s  [Compiled Java code]  MixedCall::run()                MixedCall.java  0x7fb63938009b                    
...

Analyze Hardware Metrics

VTune Profiler provides an advanced profiling option of optimizing Java applications for the CPU microarchitecture utilized in your platform. Although Java and JVM technology is intended to free a developer from hardware architecture specific coding, once Java code is optimized for the current Intel microarchitecture, it will most probably keep this advantage for future generations of CPUs.

VTune Profiler counts the number of hardware events during the hardware event-based sampling collection to help you understand how your Java application utilizes available hardware resources. Use the hw-events report type to display hardware events count per application functions in the descending order by default.
NOTE:

To display a list of available groupings for a hw-events report, enter vtune -report hw-events -r <result_dir> group-by=?.

Example

This example generates the hw-events report for the specified Hotspots analysis (hardware event-based sampling mode) result.

On Windows: 


Function               Hardware Event Count:INST_RETIRED.ANY  Hardware Event Count:CPU_CLK_UNHALTED.THREAD  Hardware Event Count:CPU_CLK_UNHALTED.REF_TSC  Hardware Event Count:BR_INST_RETIRED.NEAR_TAKEN  Hardware Event Count:ITERATION_COUNT  Hardware Event Count:LOOP_ENTRY_COUNT  Hardware Event Count:CALL_COUNT  Context Switch Time  Context Switch Time:Wait Time  Context Switch Time:Inactive Time  Context Switch Count  Context Switch Count:Preemption  Context Switch Count:Synchronization  Module          Function (Full)        Source File   Start Address
---------------------  -------------------------------------  --------------------------------------------  ---------------------------------------------  -----------------------------------------------    
consume_time                                   8,649,248,560                                28,577,118,234                                 25,656,728,125                                      126,927,912                           126,914,825                                      0                                0               0.217s                             0s                             0.217s                 4,147                            4,147                                     0  mixed_call.dll  consume_time           mixed_call.c  0x180001000 
NtWaitForSingleObject                          1,683,967,360                                 3,955,057,542                                    716,832,500                                          200,003                                     0                                      0                           66,678             223.825s                        62.467s                           161.358s                 9,030                            5,158                                 3,873  ntdll.dll       NtWaitForSingleObject  [Unknown]     0x1800906f0
WriteFile                                      1,207,593,104                                 1,022,685,972                                  1,713,743,550                                                0                                     0                                      0                           61,803               0.340s                         0.003s                             0.337s                   962                              954                                     8  KernelBase.dll  WriteFile              [Unknown]     0x180001c50

On Linux: 


Function            Hardware Event Count:INST_RETIRED.ANY  Hardware Event Count:CPU_CLK_UNHALTED.THREAD  Hardware Event Count:CPU_CLK_UNHALTED.REF_TSC Context Switch Time  Context Switch Time:Wait Time  Context Switch Time:Inactive Time  Context Switch Count  Context Switch Count:Preemption  Context Switch Count:Synchronization  Module              Function (Full)     Source File  Start Address
------------------  -------------------------------------  --------------------------------------------  --------------------------------------------- -------------------  -----------------------------    
[libmixed_call.so]                         21,148,958,284                                40,338,264,445                                 35,096,009,324              1.401s                             0s                             1.401s                26,769                           26,769                                     0  [libmixed_call.so]  [libmixed_call.so]  [Unknown]    0
[libjvm.so]                                   792,807,896                                 1,199,773,286                                  1,335,034,092              0.047s                         0.005s                             0.042s                   462                              451                                    11  [libjvm.so]         [libjvm.so]         [Unknown]    0
...

Limitations

VTune Profiler supports analysis of Java applications with some limitations:

  • System-wide profiling is not supported for managed code.

  • The JVM interprets some rarely called methods instead of compiling them for the sake of performance. VTune Profiler does not recognize interpreted Java methods and marks such calls as !Interpreter in the restored call stack.

    If you want such functions to be displayed in stacks with their names, force the JVM to compile them by using the -Xcomp option (show up as [Compiled Java code] methods in the results). However, the timing characteristics may change noticeably if many small or rarely used functions are being called during execution.

  • When opening source code for a hotspot, the VTune Profiler may attribute events or time statistics to an incorrect piece of the code. It happens due to JDK Java VM specifics. For a loop, the performance metric may slip upward. Often the information is attributed to the first line of the hot method's source code.

  • Consider events and time mapping to the source code lines as approximate.

  • For the user-mode sampling based Hotspots analysis type, the VTune Profiler may display only a part of the call stack. To view the complete stack on Windows, use the -Xcomp additional command line JDK Java VM option that enables the JIT compilation for better quality of stack walking. On Linux, use additional command line JDK Java VM options that change behavior of the Java VM:

    • Use the -Xcomp additional command line JDK Java VM option that enables the JIT compilation for better quality of stack walking.

    • On Linux* x86, use client JDK Java VM instead of the server Java VM: either explicitly specify -client, or simply do not specify -server JDK Java VM command line option.

    • On Linux x64, specify -XX:-UseLoopCounter command line option that switches off on-the-fly substitution of the interpreted method with the compiled version.

  • Java application profiling is supported for the Hotspots and Microarchitecture analysis types. Support for the Threading analysis is limited as some embedded Java synchronization primitives (which do not call operating system synchronization objects) cannot be recognized by the VTune Profiler. As a result, some of the timing metrics may be distorted.

  • There are no dedicated libraries supplying a user API for collection control in the Java source code. However, you may want to try applying the native API by wrapping the __itt calls with JNI calls.

Parent topic: Command Line Usage Scenarios
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