Intel® Advisor User Guide

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Date 3/22/2024
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Document Table of Contents
Document Table of Contents x
Intel® Advisor User Guide
Intel® Advisor User Guide x
Introduction Install and Launch Intel® Advisor Set Up Project Analyze Vectorization Perspective Analyze CPU Roofline Model Threading Designs Model Offloading to a GPU Analyze GPU Roofline Design and Analyze Flow Graphs Minimize Analysis Overhead Analyze MPI Applications Manage Results Command Line Interface Troubleshooting Reference Appendix
Introduction x
Design and Optimization Methodology Tutorials and Samples Get Help and Support
Install and Launch Intel® Advisor x
Install Intel® Advisor Set Up Environment Variables Set Up System to Analyze GPU Kernels Set Up Environment to Offload SYCL, OpenMP* target, and OpenCL™ Applications to CPU Launch Intel® Advisor GUI Navigation Quick Start
Set Up Project x
Configure Target Application Build Target Application Create Project
Configure Target Application x
Limit the Number of Threads Used by Parallel Frameworks Choose a Small, Representative Data Set
Create Project x
Configure Project Configure Binary/Symbol Search Directories Configure Source Search Directory Binary/Symbol Search and Source Search Locations
Analyze Vectorization Perspective x
Run Vectorization and Code Insights Perspective from GUI Run Vectorization and Code Insights Perspective from Command Line Explore Vectorization and Code Insights Results
Run Vectorization and Code Insights Perspective from GUI x
Vectorization Accuracy Presets Customize Vectorization and Code Insights Perspective
Run Vectorization and Code Insights Perspective from Command Line x
Vectorization Accuracy Levels in Command Line
Explore Vectorization and Code Insights Results x
Vectorization Report Overview Examine Not-Vectorized and Under-Vectorized Loops Analyze Loop Call Count Investigate Memory Usage and Traffic Find Data Dependencies
Analyze CPU Roofline x
Run CPU / Memory Roofline Insights Perspective from GUI Run CPU / Memory Roofline Insights Perspective from Command Line Explore CPU/Memory Roofline Results
Run CPU / Memory Roofline Insights Perspective from GUI x
CPU Roofline Accuracy Presets Customize CPU / Memory Roofline Insights Perspective
Run CPU / Memory Roofline Insights Perspective from Command Line x
CPU Roofline Accuracy Levels in Command Line
Explore CPU/Memory Roofline Results x
CPU Roofline Report Overview Basic Roofline Chart (Low Accuracy) Roofline with Callstacks Chart (Medium Accuracy) Memory-Level Roofline Chart (Medium Accuracy) Examine Bottlenecks on CPU Roofline Chart Examine Relationships Between Memory Levels Compare CPU Roofline Results
Model Threading Designs x
Run Threading Perspective from GUI Run Threading Perspective from Command Line Annotate Code for Deeper Analysis Explore Threading Results Model Threading Parallelism Check for Dependencies Issues Add Parallelism to Your Program
Run Threading Perspective from GUI x
Customize Threading Perspective
Run Threading Perspective from Command Line x
Threading Accuracy Levels in Command Line
Annotate Code for Deeper Analysis x
Annotate Code to Model Parallelism Annotations Annotation Report
Annotate Code to Model Parallelism x
Before Annotating Code for Deeper Analysis Use Amdahl's Law and Measure the Program Task Organization and Annotations Annotate Parallel Sites and Tasks Task Patterns Choose the Tasks Use Partially Parallel Programs with Intel® Advisor
Task Patterns x
Multiple Parallel Sites Data and Task Parallelism Mix and Match Tasks
Choose the Tasks x
Task Interactions and Suitability How Big Should a Task Be?
Annotations x
Annotation Types Annotation Definitions Files Add Annotations into Your Source Code Tips for Annotation Use with C/C++ Programs
Annotation Types x
Annotation Types Summary Annotation General Characteristics Site and Task Annotations for Simple Loops With One Task Site and Task Annotations for Parallel Sites with Multiple Tasks Lock Annotations Pause Collection and Resume Collection Annotations Special-purpose Annotations
Annotation Definitions Files x
Reference the Annotations Definitions Directory Include the Annotations Header File in C/C++ Sources
Add Annotations into Your Source Code x
Copy Annotations and Build Settings Using the Annotation Assistant Pane Insert Annotations in a Text Editor
Tips for Annotation Use with C/C++ Programs x
Control the Expansion of advisor-annotate.h Handle Compilation Issues that Appear After Adding advisor-annotate.h
Annotation Report x
Annotation Report, Clear Description of Storage Row Annotation Report, Disable Observations in Region Row Annotation Report, Pause Collection Row Annotation Report, Inductive Expression Row Annotation Report, Lock Row Annotation Report, Observe Uses Row Annotation Report, Reduction Row Annotation Report, Re-enable Observations at End of Region Row Annotation Report, Resume Collection Row Annotation Report, Site Row Annotation Report, Task Row Annotation Report, User Memory Allocator Use Row Annotation Report, User Memory Deallocator Use Row
Model Threading Parallelism x
Suitability Report Overview Choose Modeling Parameters in the Suitability Report Fix Annotation-related Errors Detected by the Suitability Tool Advanced Modeling Options Reduce Parallel Overhead, Lock Contention, and Enable Chunking
Reduce Parallel Overhead, Lock Contention, and Enable Chunking x
Reduce Site Overhead Reduce Task Overhead Reduce Lock Overhead Reduce Lock Contention Enable Task Chunking
Check for Dependencies Issues x
Code Locations Pane Filter Pane (Dependencies Report) Problems and Messages Pane Dependencies Source Window
Dependencies Source Window x
Code Locations Pane (Dependencies Source Window) Focus Code Location Pane Focus Code Location Call Stack Pane Related Code Locations Pane Related Code Location Call Stack Pane Relationship Diagram Pane
Add Parallelism to Your Program x
Before You Add Parallelism: Choose a Parallel Framework Add the Parallel Framework to Your Build Environment Annotation Report Replace Annotations with Intel® oneAPI Threading Building Blocks (oneTBB) Code Replace Annotations with OpenMP* Code Next Steps for the Parallel Program
Before You Add Parallelism: Choose a Parallel Framework x
Parallel Frameworks Intel® oneAPI Threading Building Blocks (oneTBB) OpenMP* Microsoft Task Parallel Library* (TPL) Other Parallel Frameworks
Add the Parallel Framework to Your Build Environment x
Enable Intel® oneAPI Threading Building Blocks (oneTBB) in your Build Environment Define the TBBROOT Environment Variable Enable C++11 Lambda Expression Support with Intel® oneAPI Threading Building Blocks (oneTBB) Enable OpenMP* in your Build Environment
Annotation Report x
Annotation Report Overview Locate Annotations with the Annotation Report
Replace Annotations with Intel® oneAPI Threading Building Blocks (oneTBB) Code x
Intel® oneAPI Threading Building Blocks (oneTBB) Mutexes Intel® oneAPI Threading Building Blocks (oneTBB) Simple Mutex - Example Test the Intel® oneAPI Threading Building Blocks (oneTBB) Synchronization Code Parallelize Functions - Intel® oneAPI Threading Building Blocks (oneTBB) Tasks Parallelize Data - Intel® oneAPI Threading Building Blocks (oneTBB) Counted Loops Parallelize Data - Intel® oneAPI Threading Building Blocks (oneTBB) Loops with Complex Iteration Control
Replace Annotations with OpenMP* Code x
Add OpenMP Code to Synchronize the Shared Resources OpenMP Critical Sections Basic OpenMP Atomic Operations Advanced OpenMP Atomic Operations OpenMP Reduction Operations OpenMP Locks Test the OpenMP Synchronization Code Parallelize Functions - OpenMP Tasks Parallelize Data - OpenMP Counted Loops Parallelize Data - OpenMP Loops with Complex Iteration Control
Next Steps for the Parallel Program x
Use Intel® Inspector and Intel® VTune™ Profiler Debug Parallel Programs
Model Offloading to a GPU x
Run Offload Modeling Perspective from GUI Run Offload Modeling Perspective from Command Line Explore Offload Modeling Results Advanced Modeling Configuration
Run Offload Modeling Perspective from GUI x
Offload Modeling Accuracy Presets Customize Offload Modeling Perspective
Run Offload Modeling Perspective from Command Line x
Offload Modeling Accuracy Levels in Command Line Run GPU-to-GPU Performance Modeling from Command Line
Explore Offload Modeling Results x
Offload Modeling Report Overview Examine Regions Recommended for Offloading Examine Data Transfers for Modeled Regions Check for Dependency Issues Explore Performance Gain from GPU-to-GPU Modeling Investigate Non-Offloaded Code Regions
Advanced Modeling Configuration x
Model Application Performance on a Custom Target GPU Device Check How Assumed Dependencies Affect Modeling Manage Invocation Taxes Enforce Offloading for Specific Loops
Analyze GPU Roofline x
Test Topic for Embedded Help Run GPU Roofline Insights Perspective from GUI Run GPU Roofline Insights Perspective from Command Line Explore GPU Roofline Results
Run GPU Roofline Insights Perspective from GUI x
GPU Roofline Accuracy Presets Customize GPU Roofline Insights Perspective
Run GPU Roofline Insights Perspective from Command Line x
GPU Roofline Accuracy Levels in Command Line
Explore GPU Roofline Results x
Examine GPU Roofline Summary Examine Bottlenecks on GPU Roofline Chart Examine Kernel Details Compare GPU Roofline Results
Design and Analyze Flow Graphs x
Where to Find the Flow Graph Analyzer Launching the Flow Graph Analyzer Flow Graph Analyzer GUI Overview Flow Graph Analyzer Workflows Designer Workflow Generating C++ Stubs Preferences Scalability Analysis Collecting Traces from Applications Nested Parallelism in Flow Graph Analyzer Analyzer Workflow Experimental Support for OpenMP* Applications Sample Trace Files Additional Resources
Flow Graph Analyzer GUI Overview x
Menus Toolbars Tabs Main Canvas Charts
Designer Workflow x
Adding Nodes, Edges, and Ports Modifying Node Properties Viewing Edge Properties Validating a Graph Saving a Graph to a File
Scalability Analysis x
Activating the Graph Scalability Analysis Prerequisites Running the Scalability Analysis Exploring the Parallelism in a Concurrent Node Showing Non-Parallel Nature of a Serial Node Explore Parallelism Provided by the Topology of a Graph Understanding Analysis Color Codes
Scalability Analysis Prerequisites x
Setting Concurrency Specification Setting Data Count Setting Node Weight
Collecting Traces from Applications x
Building an Application for Trace Collection Collecting Trace Files
Building an Application for Trace Collection x
Building an Application on Windows* OS Building an Application on Linux* OS Building an Application on macOS*
Collecting Trace Files x
Collect Traces In the Flow Graph Analyzer GUI Collect Traces Outside the Flow Graph Analyzer GUI
Collect Traces Outside the Flow Graph Analyzer GUI x
Collecting Trace Files with fgtrun Script Collecting Trace Files without fgtrun Script
Analyzer Workflow x
Find Time Regions of Low Concurrency and Their Cause Finding a Critical Path Finding Tasks with Small Durations Reduce Scheduler Overhead using Lightweight Policy Identifying Tasks that Operate on Common Input Support for SYCL
Support for SYCL x
Collect SYCL Application Traces Examine a SYCL Application Graph Find Issues Using Static Rule-check Engine
Examine a SYCL Application Graph x
Hotspot View View Performance Inefficiencies of Data-parallel Constructs
Find Issues Using Static Rule-check Engine x
Issue: Const Reference to a Host Pointer Used to Initialize a Buffer Issue: Host Pointer Accessor Used in a Loop Issue: Data Parallel Construct Inefficiency
Experimental Support for OpenMP* Applications x
Collecting Traces for OpenMP* Applications OpenMP* Constructs in the Per-Thread Task View OpenMP* Constructs in the Graph Canvas
Sample Trace Files x
code_generation Samples performance_analysis Samples
Minimize Analysis Overhead x
Collection Controls to Minimize Analysis Overhead Loop Markup to Minimize Analysis Overhead Filtering to Minimize Analysis Overhead Execution Speed/Duration/Scope Properties to Minimize Analysis Overhead Miscellaneous Techniques to Minimize Analysis Overhead
Analyze MPI Applications x
Model MPI Application Performance on GPU Control Collection with an MPI_Pcontrol Function
Manage Results x
Open a Result Rename an Existing Result Delete a Result Save Results to a Custom Location Work with Standalone HTML Reports Create a Read-only Result Snapshot Create a Result Snapshot Dialog Box
Command Line Interface x
advisor Command Line Interface Reference Offload Modeling Command Line Reference Generate Pre-configured Command Lines
advisor Command Line Interface Reference x
advisor Command Action Reference advisor Command Option Reference
advisor Command Action Reference x
collect command create-project help import-dir mark-up-loops report snapshot version workflow
advisor Command Option Reference x
accuracy append app-working-dir assume-dependencies assume-hide-taxes assume-ndim-dependency assume-single-data-transfer auto-finalize batching benchmarks-sync bottom-up cache-binaries cache-binaries-mode cache-config cache-simulation cache-sources cachesim cachesim-associativity cachesim-cacheline-size cachesim-mode cachesim-sampling-factor cachesim-sets check-profitability clear config count-logical-instructions count-memory-instructions count-memory-objects-accesses count-mov-instructions count-send-latency cpu-scale-factor csv-delimiter custom-config data-limit data-reuse-analysis data-transfer data-transfer-histogram data-transfer-page-size data-type delete-tripcounts disable-fp64-math-optimization display-callstack dry-run duration dynamic enable-cache-simulation enable-data-transfer-analysis enable-task-chunking enforce-baseline-decomposition enforce-fallback enforce-offloads estimate-max-speedup evaluate-min-speedup exclude-files executable-of-interest exp-dir filter filter-by-scope filter-reductions flop force-32bit-arithmetics force-64bit-arithmetics format gpu gpu-carm gpu-kernel-of-interest gpu-sampling-interval hide-data-transfer-tax ignore ignore-app-mismatch ignore-checksums instance-of-interest integrated interval limit loop-call-count-limit loop-filter-threshold loops mark-up mark-up-list memory-level memory-operation-type mix mkl-user-mode model-baseline-gpu model-children model-extended-math model-system-calls module-filter module-filter-mode mpi-rank mrte-mode ndim-depth-limit option-file overlap-taxes pack profile-gpu profile-intel-perf-libs profile-jit profile-python profile-stripped-binaries project-dir quiet recalculate-time record-mem-allocations record-stack-frame reduce-lock-contention reduce-lock-overhead reduce-site-overhead reduce-task-overhead refinalize-survey remove report-output report-template result-dir resume-after return-app-exitcode search-dir search-n-dim select set-dependency set-parallel set-parameter show-all-columns show-all-rows show-functions show-loops show-not-executed show-report small-node-filter sort-asc sort-desc spill-analysis stack-access-granularity stack-stitching stack-unwind-limit stacks stackwalk-mode start-paused static-instruction-mix strategy support-multi-isa-binaries target-device target-gpu target-pid target-process target-system threading-model threads top-down trace-mode trace-mpi track-memory-objects track-stack-accesses track-stack-variables trip-counts verbose with-stack
Offload Modeling Command Line Reference x
run_oa.py Options collect.py Options analyze.py Options
Troubleshooting x
Error Message: Application Sets Its Own Handler for Signal Error Message: Cannot Collect GPU Hardware Metrics for the Selected GPU Adapter Error Message: Memory Model Cache Hierarchy Incompatible Error Message: No Annotations Found Error Message: No Data Is Collected Error Message: Stack Size Is Too Small Error Message: Undefined Linker References to dlopen or dlsym Problem: Broken Call Tree Problem: Code Region is not Marked Up Problem: Debug Information Not Available Problem: No Data Problem: Source Not Available Problem: Stack in the Top-Down Tree Window Is Incorrect Problem: Survey Tool does not Display Survey Report Problem: Unexpected C/C++ Compilation Errors After Adding Annotations Problem: Unexpected Unmatched Annotations in the Dependencies Report Warning: Analysis of Debug Build Warning: Analysis of Release Build
Reference x
Data Reference Dependencies Problem and Message Types Recommendation Reference User Interface Reference
Data Reference x
CPU Metrics Accelerator Metrics
Dependencies Problem and Message Types x
Dangling Lock Data Communication Data Communication, Child Task Inconsistent Lock Use Lock Hierarchy Violation Memory Reuse Memory Reuse, Child Task Memory Watch Missing End Site Missing End Task Missing Start Site Missing Start Task No Tasks in Parallel Site One Task Instance in Parallel Site Orphaned Task Parallel Site Information Thread Information Unhandled Application Exception
Recommendation Reference x
Vectorization Recommendations for C++ Vectorization Recommendations for Fortran
User Interface Reference x
Dialog Box: Corresponding Command Line Dialog Box: Create a Project Dialog Box: Create a Result Snapshot Dialog Box: Options - Assembly Editor Tab Dialog Box: Options - General Dialog Box: Options - Result Location Dialog Box: Project Properties - Analysis Target Dialog Box: Project Properties - Binary/Symbol Search Dialog Box: Project Properties - Source Search Pane: Advanced View Pane: Analysis Workflow Pane: Roofline Chart Pane: GPU Roofline Chart Project Navigator Pane Toolbar: Intel Advisor Annotation Report Window: Dependencies Source Window: GPU Roofline Regions Window: GPU Roofline Insights Summary Window: Memory Access Patterns Source Window: Offload Modeling Summary Window: Offload Modeling Report - Accelerated Regions Window: Perspective Selector Window: Refinement Reports Window: Suitability Report Window: Suitability Source Window: Survey Report Window: Survey Source Window: Threading Summary Window: Vectorization Summary
Window: Refinement Reports x
Tab: Dependencies Report Tab: Memory Access Patterns Report
Appendix x
Data Sharing Problems Notational Conventions Key Concepts Related Information
Data Sharing Problems x
Data Sharing Problem Types Problem Solving Strategies
Data Sharing Problem Types x
Incidental Sharing Independent Updates
Problem Solving Strategies x
Eliminate Incidental Sharing Synchronize Independent Updates Difficult Problems: Choosing a Different Set of Tasks Fix Problems in Code Used by Multiple Parallel Sites Memory That is Accessed Through a Pointer
Eliminate Incidental Sharing x
Examine the Task's Static and Dynamic Extent Verify Whether Incidental Sharing Exists Create the Private Memory Location Pointer Dereferences
Synchronize Independent Updates x
Synchronization Explicit Locking Assign Locks to Transactions Pitfalls from Using Synchronization
Key Concepts x
Glossary Parallelism
Parallelism x
Parallel Processing Terminology Add Parallelism Common Issues When Adding Parallelism Parallel Programming Implementations
Intel® Advisor User Guide

CPU Roofline Report Overview

Review the controls available in the main report of the CPU / Memory Roofline Insights perspective of the Intel® Advisor.

Basic Roofline Chart (Low Accuracy)

There are several controls to help you focus on the Roofline chart data most important to you, including the following.


1

  • Select Loops by Mouse Rect: Select one or more loops/functions by tracing a rectangle with your mouse.

  • Zoom by Mouse Rect: Zoom in and out by tracing a rectangle with your mouse. You can also zoom in and out using your mouse wheel.

  • Move View By Mouse: Move the chart left, right, up, and down.

  • Undo or Redo: Undo or redo the previous zoom action.

  • Cancel Zoom: Reset to the default zoom level.

  • Export as x: Export the chart as a dynamic and interactive HTML or SVG file that does not require the Intel Advisor viewer for display. Use the arrow to toggle between the options.

2

Use the Cores drop-down toolbar to:

  • Adjust rooflines to see practical performance limits for your code on the host system.

  • Build roofs for single-threaded applications (or for multi-threaded applications configured to run single threaded, such as one thread-per-rank for MPI applications. (You can use Intel Advisor filters to control the loops displayed in the Roofline chart; however, the Roofline chart does not support the Threads filter.)

Choose the appropriate number of CPU cores to scale roof values up or down:

  • 1 – if your code is single-threaded

  • Number of cores equal or close to the number of threads – if your code has fewer threads than available CPU cores

  • Maximum number of cores – if your code has more threads than available CPU cores

By default, the number of cores is set to the number of threads used by the application (even values only).

You’ll see the following options if your code is running on a multisocket PC:

  • Choose Bind cores to 1 socket (default) if your application binds memory to one socket. For example, choose this option for MPI applications structured as one rank per socket.

    NOTE:
    This option may be disabled if you choose a number of CPU cores exceeding the maximum number of cores available on one socket.

  • Choose Spread cores between all n sockets if your application binds memory to all sockets. For example, choose this option for non-MPI applications.

3

  • Toggle the display between floating-point (FLOP), integer (INT) operations, and mixed operations (floating-point and integer).

  • If you collected Roofline with Calltacks: Enable the display of Roofline with Callstacks additions to the Roofline chart.

4

Display Roofline chart data from other Intel Advisor results or non-archived snapshots for comparison purposes.

Use the drop-down toolbar to:

  • Load a result/snapshot and display the corresponding filename in the Compared Results region.

  • Clear a selected result/snapshot and move the corresponding filename to the Ready for comparison region.

    Note: Click a filename in the Ready for comparison region to reload the result/snapshot.

  • Save the comparison itself to a file.

    NOTE:
    The arrowed lines showing the relationship among loops/functions do not reappear if you upload the comparison file.

Click a loop/function dot in the current result to show the relationship (arrowed lines) between it and the corresponding loop/function dots in loaded results/snapshots.

5

Add visual indicators to the Roofline chart to make the interpretation of data easier, including performance limits and whether loops/functions are memory bound, compute bound, or both.

Use the drop-down toolbar to:

  • Show a vertical line from a loop/function to the nearest and topmost performance ceilings by enabling the Display roof rulers checkbox. To view the ruler, hover the cursor over a loop/function. Where the line intersects with each roof, labels display hardware performance limits for the loop/function.

  • If you collected Roofline for All Memory Levels: Visually emphasize the relationships among displayed memory levels and roofs and for a selected loop/function dot by enabling the Show memory level relationships checkbox.

  • Color the roofline zones to make it easier to see if enclosed loops/functions are fundamentally memory bound, compute bound, or bound by compute and memory roofs by enabling the Show Roofline boundaries checkbox.

The preview picture is updated as you select guidance options, allowing you to see how changes will affect the Roofline chart’s appearance. Click Apply to apply your changes, or Default to return the Roofline chart to its original appearance.

Once you have a loop/function's dots highlighted, you can zoom and fit the Roofline chart to the dots for the selected loop/function by once again double-clicking the loop/function or pressing SPACE or ENTER with the loop/function selected. Repeat this action to return to the original Roofline chart view.

To hide the labeled dots, select another loop/function, or double-click an empty space in the Roofline chart.

6

  • Roofline View Settings: Adjust the default scale setting to show:

    • The optimal scale for each Roofline chart view

    • A scale that accommodates all Roofline chart views

  • Roofs Settings: Change the visibility and appearance of roofline representations (lines):

    • Enable calculating roof values based on single-threaded benchmark results instead of multi-threaded.
    • Click a Visible checkbox to show/hide a roofline.
    • Click a Selected checkbox to change roofline appearance: display a roofline as a solid or a dashed line.
    • Manually fine-tune roof values in the Value column to set hardware limits specific to your code.

  • Loop Weight Representation: Change the appearance of loop/function weight representations (dots):

    • Point Weight Calculation: Change the Base Value for a loop/function weight calculation.
    • Point Weight Ranges: Change the Size, Color, and weight Range (R) of a loop/function dot. Click the + button to split a loop weight range in two. Click the - button to merge a loop weight range with the range below.
    • Point Colorization: color loop/function dots by weight ranges or by type (vectorized or scalar). You can also change the color of loop with no self time.

You can save your Roofs Settings or Point Weight Representation configuration to a JSON file or load a custom configuration.

7

Zoom in and out using numerical values.

8

Click a loop/function dot to:

  • Outline it in black.

  • Display metrics for it.

  • Display corresponding data in other window tabs.

Right-click a loop/function dot or a blank area in the Roofline chart to perform more functions, such as:

  • Further simplify the Roofline chart by filtering out (temporarily hiding a dot), filtering in (temporarily hiding all other dots), and clearing filters (showing all originally displayed dots).

  • Copy data to the clipboard.

9

Show/hide the metrics pane:

  • Review the basic performance metrics in the Point Info pane.
  • If you collected the Roofline for All Memory Levels: Review how efficiently the loop/function uses cache and what memory level bounds the loop/function in the Memory Metrics pane.

10

Display the number and percentage of loops in each loop weight representation category.

Roofline with Callstacks Chart (Medium Accuracy)



1

Enable the display of Roofline with Callstacks additions to the Roofline chart.

2

Show/hide loop/function descendants:

  • Click a loop/function dot control to collapse descendant dots into the parent dot.

  • Click a loop/function dot control to show descendant dots and their relationship via visual indicators to the parent dot.

You can also right-click a loop/function dot to open the context menu and expand/collapse the loop/function subtree.

3

Show/hide the Callstack and other panes.

4
  • Click an item in the Callstack pane to flash the corresponding loop/function dot in the Roofline chart.
  • Right-click an item in the Callstack pane to open the context menu and expand/collapse the item subtree.

You can also click an item in the Callstack pane to flash the corresponding loop/function dot in the Roofline chart.

Memory-Level Roofline Chart (Medium Accuracy)



1

Visually emphasize the relationships among displayed memory levels and roofs for a selected loop/function dot by enabling the Show memory level relationships checkbox.

NOTE:
This checkbox is enabled by default.

2

Use the drop-down toolbar to:

  • Select the Memory Level(s) to show for each loop/function in the chart (L1, L2, L3, DRAM).

  • Select which Memory Operation Types(s) to display data for in the Roofline chart: Loads, Stores, or Loads and Stores.

3

Double-click a dot or select a dot and press SPACE or ENTER to examine how the relationships between displayed memory levels and roofs:

  • Labeled dots are displayed, representing memory levels for the selected loop/function. Lines connect the dots to indicate that they correspond to the selected loop/function.

    NOTE:
    If you have chosen to display only some memory levels in the chart using the Memory Level option, unselected memory levels are displayed with X marks.

  • An arrowed line is displayed, pointing to the memory level roofline that bounds the selected loop. If the arrowed line cannot be displayed, a message will pop up with instructions on how to fix it.

4

Show/hide the Memory Metrics and other panes.

In the Memory Metrics pane:

  • Review the time spent processing requests for each memory level reported in the Impacts histogram. A big value indicates a memory level that bounds the selected loop.
  • Review an amount of data that passes through each memory level reported in the Shares histogram.
Parent topic: Explore CPU/Memory Roofline Results
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