Introduction to the Intel® Performance Tuning Utility 2 · mkdir \PTU • unzip package into \PTU • cd \PTU\iptu2.0_001_win_ Arch \bin • Arch = ia32 or intel64 • install_sep.exe

Introduction to the Intel® Performance Tuning Utility 2.0

http://www.intel.com/software/productsCopyright © 2007, Intel Corporation. All rights reserved.

David Levinthal Technical Consulting Engineer

Developer Product Division

Software and Solutions Group

2

• INFORMATION IN THIS DOCUMENT IS PROVIDED IN CONNECTION WITH INTEL® PRODUCTS. NO LICENSE, EXPRESS OR IMPLIED, BY ESTOPPEL OR OTHERWISE, TO ANY INTELLECTUAL PROPERTY RIGHTS IS GRANTED BY THIS DOCUMENT. EXCEPT AS PROVIDED IN INTEL’S TERMS AND CONDITIONS OF SALE FOR SUCH PRODUCTS, INTEL ASSUMES NO LIABILITY WHATSOEVER, AND INTEL DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTY, RELATING TO SALE AND/OR USE OF INTEL PRODUCTS INCLUDING LIABILITY OR WARRANTIES RELATING TO FITNESS FOR A PARTICULAR PURPOSE, MERCHANTABILITY, OR INFRINGEMENT OF ANY PATENT, COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT. Intel products are not intended for use in medical, life saving, or life sustaining applications.

• Intel may make changes to specifications and product descriptions at any time, without notice.

• Designers must not rely on the absence or characteristics of any features or instructions marked "reserved" or "undefined." Intel reserves these for future definition and shall have no responsibility whatsoever for conflicts or incompatibilities arising from future changes to them.

• The Intel® Performance Tuning Utility may contain design defects or errors known as errata which may cause the product to deviate from published specifications. Current characterized errata are available on request.

• Contact your local Intel sales office or your distributor to obtain the latest specifications and before placing your product order.

• Use only if applicable: I2C is a two-wire communications bus/protocol developed by Philips. SMBus is a subset of the I2C bus/protocol and was developed by Intel. Implementations of the I2C bus/protocol may require licenses from various entities, including Philips Electronics N.V. and North American Philips Corporation.

• Use only if applicable: Alert on LAN is a result of the Intel-IBM Advanced Manageability Alliance and a trademark of IBM

• This document contains information on products in the design phase of development. Do not finalize a design with this information. Revised information will be published when the product is available. Verify with your local sales office that you have the latest datasheet before finalizing a design.

• PTU and other code names featured are used internally within Intel to identify products that are in development and not yet publicly announced for release. Customers, licensees and other third parties are not authorized by Intel to use code names in advertising, promotion or marketing of any product or services and any such use of Intel's internal code names is at the sole risk of the user.

• All dates specified are target dates, are provided for planning purposes only and are subject to change.

• All products, dates, and figures specified are preliminary based on current expectations, provided for planning purposes only, and are subject to change without notice.

• Intel, the Intel logo, Vtune and Core are trademarks or registered trademarks of Intel Corporation or its subsidiaries in the United States and other countries.

• *Other names and brands are the property of their respective owners.

• Copyright © 2007, Intel Corporation

Legal Disclaimer

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Outline

• Installation

• Recommended usage

• This is what I do• I make sure what I do works• Do the same, you are less likely to have trouble• Note: if you do have trouble, you will be told to do what I do

anyway

• ☺

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Intel® PTU Overview

• Eclipse* based, modular tool• Underlying command line structure• Virtually identical on Windows* and Linux*

• Available at: http://whatif.intel.com

• Targeting Expert Users• Internal tool used at Intel Corp.

• Preview of new design and usage

• Focus on Features

*Other names and brands may be claimed as property of others

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Installation and startup on Windows*

• Select the right package

• IA32 package will not work on Intel64 systems and vice versa

• mkdir \PTU

• unzip package into \PTU

• cd \PTU\iptu2.0_001_win_Arch\bin

• Arch = ia32 or intel64

• install_sep.exe

• cd ..\eclipse

• eclipse.exe

You are Ready to Start*Other names and brands may be claimed as property of others

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Installation and startup on Linux* MUST BE DONE AS ROOT• Select the right package

• IA32 package will not work on Intel64 systems and vice versa

• mkdir /PTU

• unzip package into /PTU

• cd /PTU/iptu2.0_001_win_Arch/vdk• Arch = ia32 or intel64

• ./insmod_vtune• This installs the driver and uses the group ‘vtune’• See next slide for potential issues and solutions

• cd ../eclipse

• ./eclipse

You are Ready to Start*Other names and brands may be claimed as property of others

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Driver Installation and Groups on Linux* MUST BE DONE AS ROOT

• Invoking insmod_vtune can fail under a variety of circumstances

• Vtune™ Analyzer driver already installed• Your OS distribution does not have a prebuilt driver in package• Group ‘vtune’ does not exist

• Removing existing driver

• In vdk directory invoke ./rmmod_vtune

• Create group vtune with groupadd vtune

• Add all user to this group with usermod –G vtune userid– User must log out for this to take effect


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Driver Installation and Groups on Linux* MUST BE DONE AS ROOT• Changing default group (pwd = vdk)

• Edit insmod_vtune and locate MACHINE_TYPE=`${UNAME} -m` DRIVER_DIRECTORY=. DRIVER_GROUP=vtune DRIVER_PERMS=660

• Building a driver for your OS distribution• You MUST have OS sources in standard places

• cd src (/PTU/iptu2.0_001_lin_arch/vdk/src)

• ./build_driver• Accept all defaults

• Move driver up to vdk directory

• ./insmod_vtune

Set this to desired group


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Usage of the Intel® Performance Tuning Utility

• What follows are screen shots of the sequence of graphical interfaces you will encounter when you use PTU

• Most are done on Windows*, but they would look identical on Linux*

• Except that \ -> /


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Invoking eclipse* (Windows*)


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Recommendation Put workspace at top level and add version & username to allow multiple users and tool upgrades

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On Linux*


13

Eclipse*

Kill this off


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Eclipse*


15

Start a Project

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Starting a Project hit next

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I always use the app name, compiler, etc in the project name

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Stack Sampling simple test of call chains, with loops in functions to use time

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Define the Project Properties

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This is the Linux* Browser


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This is the Linux* Browser


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More leads to Advanced properties Change Sample after multiplier for long runs (you really don’t need more than 100,000 samples…)

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Finish Project Properties yields

Just Say Yes

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Intel® PTU Eclipse Perspective Appears because you defined a PTU Project

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Predefined Data Collections (right click on project) Let’s choose Statistical Call Graph!

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Predefined Profiles

• Right click on project in “Tuning Navigator”

• Move mouse to “Profile as >”

• Basic Data Profiling

• Profile Addresses with Intel® Processor Precise Event Based Sampling (PEBS)

• Basic Sampling

• Basic Event Based Sampling (EBS)• CPU cycles (clockticks) and Instructions Retired

• Basic Statistical Callgraph

• Time based Stack Sampling

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OOPS..no License

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OOPS..no License

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Collecting Statistical CallGraph data in \workspace2.0_lev\2007_08_30_13-37-17

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Base Callgraph Display

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Expanding the Stack (by clicking the > “arrow”) from f4 to main foo does nothing but call f4, main calls f1 in a loop

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Creating Another New Project Select New Intel® PTU Project

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Basic Sampling on a Matrix Multiply

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OOPS..No Driver Also, Rebooting may reload the VTune™ Analyzer Driver, But not the PTU driver..and they may not be compatible On Linux*, after rebooting, execute rmmod-vtune then insmod-vtune. On windows* execute install_sep.exe


Intel, the Intel logo and Core are trademarks or registered trademarks of the Intel Corporation or its subsidiaries in the United States and other countries.

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OOPS..No Driver Also, Rebooting may reload the VTune™ Analyzer Driver, But not the PTU driver..and they may not be compatible On Linux*, after rebooting, execute rmmod-vtune then insmod-vtune. On Windows* execute install_sep.exe



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OOPS..No Driver If you do this Regularly..You get the short form

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The Hotspot View shows all significant functions in all modules of all processes double click on the function to drill down to source

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The Source view uses Basic Blocks as underlying unit of execution

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The Source view uses Basic Blocks to define hot regions

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Double click on Folder Tab to Maximize the display (works for all displays) Double click again to get back to display of all panes

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Add the Control Flow Graph

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All Three at once

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Collapse the Basic Blocks in the Disassembly Display

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Basic Block Rows Display Totals For the Block Sort the Basic Blocks by clicking on the column header (just like in the hotspot view)

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Double Click on the basic block of interest The other two frames move to that spot clicking address column header resorts asm by address

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Totals for Highlighted regions appear at the Bottom (just like in Hotspot View)

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Control Flow Graph Tooltip is the Disassembly Spreadsheet for that Basic Block F2 will move focus to tool tip

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With Focus Set, Tooltip can be resized, column widths changed, exported to CSV (like all spreadsheets in all views). closes tool tip

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Nested Loop In Control Flow Graph

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Data Profiling

• Intel® Pentium® processors, Intel® Core™2 processor family and Itanium® Processor family have Precise Event Based Sampling

• Precise events have hardware to capture the Instruction Pointer of the instruction that caused the event

• Ex: On Intel® Core™2 Processor family, an L2 load miss that retrieves a cacheline can be identified with MEM_LOAD_RETIRED.L2_LINE_MISS

• Further the values of all registers are also captured in a buffer

• at completion of the instruction on Intel® Core™2 Processor Family• Prior to execution of the instruction on Pentium® 4 Processors

• Coupled with the disassembly, the addresses of load and store instructions can be reconstructed

Intel, the Intel logo, Pentium, Itanium, and Core are trademarks or registered trademarks of the Intel Corporation or its subsidiaries in the United States and other countries.

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PEBS BUFFER of Intel® Pentium® processors and Intel® Core™2 Processor family

RFLAGSRIPRAXRBXRCXRDXRSIRDIRBPRSPR8

R15

063BTS Buffer Base

BTS Index

BTS Absolute Maximum

BTS Interrupt Threshold

PEBS Buffer Base

PEBS Index

PEBS Absolute Maximum

PEBS Interrupt Threshold

063

PEBS Counter Reset

0H

8H

10H

18H

20H

28H

30H

38H

40H

0H8H10H18H20H28H30H38H40H48H50H

88H

DS Buffer Managment PEBS Record

PEBS Mechanism Captures All Registers at Completion of Triggering

InstructionPEBS + Disassembly = load Address

Intel, the Intel logo, Pentium and Core are trademarks or registered trademarks of the Intel Corporation or its subsidiaries in the United States and other countries.

52

Modify the Properties of an Existing Project Data Profiling may work better with Event Multiplexing

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Select Multiplexing to Collect all (Precise) Events in one collection run

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HITM Test: Basic Data Profiling

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Select DataProfiling View

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Two Threads Access this Line

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Expanding the “arrow” we see the 2 threads access the line at Different Offsets…This is False Sharing

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Select the falsely shared cacheline and Filter the Hotspot view to only Display Accesses to that Line Highlighting multiple Cachelines will filter on all of them

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You can also highlight a function(s) in the Hotspot view and display only its lines

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The “Address Hotspot” Spreadsheet now only shows the lines accessed by the selected functions

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Only Events Referencing the Selected Line(s) are now in the Hotspot View

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The Volatile Pointer “sum” is Causing the False Sharing

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Use the Profile Option to Create Your Own Profile

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The Configuration Editor

65Intel, the Intel logo and Core are trademarks or registered trademarks of the Intel Corporation or its

subsidiaries in the United States and other countries.

66

When You Select Event Based Sampling You MUST have the Driver Installed to identify your CPU

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Select Event Based Sampling, Disable Loop Analysis and Statistical Call Graph


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Let’s Add Some Events


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Select the Desired Events, They Can be Found with the Filter or the Scroll Bar


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Highlighting an Event Makes its Description Appear…This is the Precise L2 Miss due to Loads that Causes a Cacheline to be Transferred from Memory


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Selecting Execution Stall Cycles When You have selected all your events, Hit “OK”


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Basic 2 Run Collection for Intel® Core™2 Processor family

Set Profile Name to Something Obvious


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Click on Sample After Value to Change it (mem_load_retired.l2_line_miss should be 10K)


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“Apply” to save Your Configuration


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Basic_two_run can be reused for all future Projects The Configuration is Saved in the Workspace Directory


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Get Commands to Capture Underlying Command Line that PTU Invokes to create a Script


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Down “arrow” Enables Command Capture to Clipboard


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Basic_two_run Commands First Collects EBS Data in TB5 file Second Collects Symbolic Data to Create Displays• C:\PTU\iptu2.0_001_win_ia32\eclipse\plugins\..\..\bin\vtsarun.exe

${experiment_dir} -s -ec MEM_LOAD_RETIRED.L2_LINE_MISS:sa=10000,BUS_TRANS_BURS T.SELF:sa=100000,RS_UOPS_DISPATCHED.CYCLES_NONE:sa=200 0000,CPU_CLK_UNHALTED.CORE:sa=2000000,MEM_LOAD_RETIRE D.L2_MISS:sa=100000,INST_RETIRED.ANY:sa=2000000 -- C:\mini_app_old\matrix_mult\block\matrix_blk.exe

• Collects data in *.tb5 file

• C:\PTU\iptu2.0_001_win_ia32\eclipse\plugins\..\..\bin\vtsaview.exe ${experiment_dir} --convert --search-config "C:\Documents and Settings\levinth\Application Data\PTU2\searchdirs.xml“

• Creates symbol database for displays making results directory transportable

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Profile Button Will Start Data Collection Future Reuse of Basic_two_run is done from this Dialog


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Profile Configurations for Basic Sampling (Note: They may not appear here until you use them at least once)


81

Profile Configurations for Basic Statistical Callgraph (Note: They may not appear here until you use them at least once)


82

Profile Configurations for Basic Data Profiling (Note: They may not appear here until you use them at least once)


83

Creating Your Own Data Profile Use Precise Events


84

Creating Your Own Data Profile Enable Data Profiling to capture full PEBS buffer


85

For Long Runs, Raise all the Sample After Values at once…10X is good for runtimes > 10 min.

86

Intel® Performance Tuning Utility has a diverse set of command line utilities, including displays (*view.exe)Directory of C:\PTU\iptu2.0_001_win_ia32\bin

08/29/2007 05:59 PM 65,536 btree.exe

08/29/2007 05:59 PM 36,864 cgconvertor.exe

08/29/2007 05:59 PM 13,824 collapse.exe

08/29/2007 05:59 PM 126,976 dloop.exe

08/29/2007 05:07 PM 8,192 install_sep.exe

08/29/2007 05:59 PM 53,248 ismimp.exe

08/29/2007 05:09 PM 26,112 sep.exe

08/29/2007 06:12 PM 2,625,536 vtdpview.exe

08/29/2007 05:10 PM 86,016 vtqfagnt.exe

08/29/2007 05:59 PM 1,138,688 vtsadiff.exe

08/29/2007 05:32 PM 4,169,728 vtsarun.exe

08/29/2007 05:53 PM 2,449,408 vtsaview.exe

08/29/2007 05:58 PM 4,870,144 vtssdump.exe

08/29/2007 05:33 PM 2,330,624 vtssrun.exe

08/29/2007 06:02 PM 1,077,248 vtssview.exe

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Summary

•The Intel® Performance Tuning Utility enables unprecedented performance analysis capabilities

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Introduction to the �Intel® Performance Tuning Utility 2.0Legal DisclaimerOutlineIntel® PTU OverviewInstallation and startup on Windows*Installation and startup on Linux*�MUST BE DONE AS ROOTDriver Installation and Groups on Linux*�MUST BE DONE AS ROOTDriver Installation and Groups on Linux*�MUST BE DONE AS ROOTUsage of the Intel® Performance Tuning UtilityInvoking eclipse* (Windows*)Recommendation�Put workspace at top level and add version & username to allow multiple users and tool upgradesOn Linux*Eclipse*Eclipse*Start a ProjectStarting a Project�hit nextI always use the app name, compiler, etc in the project nameStack Sampling�simple test of call chains, with loops in functions to use timeDefine the Project PropertiesThis is the Linux* BrowserThis is the Linux* BrowserMore leads to Advanced properties�Change Sample after multiplier for long runs�(you really don’t need more than 100,000 samples…)Finish Project Properties yieldsIntel® PTU Eclipse Perspective�Appears because you defined a PTU ProjectPredefined Data Collections�(right click on project)�Let’s choose Statistical Call Graph!Predefined ProfilesOOPS..no LicenseOOPS..no LicenseCollecting Statistical CallGraph data in�\workspace2.0_lev\2007_08_30_13-37-17Base Callgraph DisplayExpanding the Stack (by clicking the > “arrow”) �from f4 to main�foo does nothing but call f4, main calls f1 in a loopCreating Another New Project�Select New Intel® PTU ProjectBasic Sampling on a Matrix MultiplyOOPS..No Driver�Also, Rebooting may reload the VTune™ Analyzer Driver, �But not the PTU driver..and they may not be compatible�On Linux*, after rebooting, execute rmmod-vtune then insmod-vtune. On windows* execute install_sep.exeOOPS..No Driver�Also, Rebooting may reload the VTune™ Analyzer Driver, �But not the PTU driver..and they may not be compatible�On Linux*, after rebooting, execute rmmod-vtune then insmod-vtune. On Windows* execute install_sep.exeOOPS..No Driver�If you do this Regularly..You get the short formThe Hotspot View shows all significant functions in all modules of all processes�double click on the function to drill down to sourceThe Source view uses Basic Blocks as underlying unit of executionThe Source view uses Basic Blocks to define hot regionsDouble click on Folder Tab to Maximize the display (works for all displays)�Double click again to get back to display of all panesAdd the Control Flow GraphAll Three at onceCollapse the Basic Blocks in the Disassembly DisplayBasic Block Rows Display Totals For the Block�Sort the Basic Blocks by clicking on the column header (just like in the hotspot view)Double Click on the basic block of interest�The other two frames move to that spot�clicking address column header resorts asm by address�Totals for Highlighted regions appear at the Bottom (just like in Hotspot View)Control Flow Graph Tooltip is the Disassembly Spreadsheet for that Basic Block�F2 will move focus to tool tipWith Focus Set, Tooltip can be resized, column widths changed, exported to CSV (like all spreadsheets in all views). closes tool tipNested Loop In Control Flow GraphData ProfilingPEBS BUFFER of Intel® Pentium® processors and Intel® Core™2 Processor familyModify the Properties of an Existing Project�Data Profiling may work better with Event MultiplexingSelect Multiplexing to Collect all (Precise) Events in one collection runHITM Test: Basic Data ProfilingSelect DataProfiling ViewTwo Threads Access this LineExpanding the “arrow” we see the 2 threads access the line at Different Offsets…This is False SharingSelect the falsely shared cacheline and Filter the Hotspot view to only Display Accesses to that Line�Highlighting multiple Cachelines will filter on all of themYou can also highlight a function(s) in the Hotspot view and display only its linesThe “Address Hotspot” Spreadsheet now only shows the lines accessed by the selected functionsOnly Events Referencing the Selected Line(s) are now in the Hotspot ViewThe Volatile Pointer “sum” is Causing the False SharingUse the Profile Option to Create Your Own ProfileThe Configuration EditorSlide Number 65When You Select Event Based Sampling You MUST have the Driver Installed to identify your CPUSelect Event Based Sampling, Disable Loop Analysis and Statistical Call GraphLet’s Add Some EventsSelect the Desired Events, They Can be Found with the Filter or the Scroll BarHighlighting an Event Makes its Description Appear…This is the Precise L2 Miss due to Loads that Causes a Cacheline to be Transferred from MemorySelecting Execution Stall Cycles�When You have selected all your events, Hit “OK”Basic 2 Run Collection for Intel® Core™2 Processor�family�Set Profile Name to Something ObviousClick on Sample After Value to Change it�(mem_load_retired.l2_line_miss should be 10K)“Apply” to save Your ConfigurationBasic_two_run can be reused for all future Projects�The Configuration is Saved in the Workspace DirectoryGet Commands to Capture Underlying Command Line that PTU Invokes to create a ScriptDown “arrow” Enables Command Capture to ClipboardBasic_two_run Commands�First Collects EBS Data in TB5 file�Second Collects Symbolic Data to Create DisplaysProfile Button Will Start Data Collection�Future Reuse of Basic_two_run is done from this DialogProfile Configurations for Basic Sampling�(Note: They may not appear here until you use them at least once)Profile Configurations for Basic Statistical Callgraph�(Note: They may not appear here until you use them at least once)Profile Configurations for Basic Data Profiling�(Note: They may not appear here until you use them at least once)Creating Your Own Data Profile�Use Precise EventsCreating Your Own Data Profile�Enable Data Profiling to capture full PEBS bufferFor Long Runs, Raise all the Sample After Values at once…10X is good for runtimes > 10 min.Intel® Performance Tuning Utility has a diverse set of command line utilities, including displays (*view.exe)SummarySlide Number 88