Intel® Advisor User Guide

User Guide

Contents

Minimize
 Analysis Overhead

Running your target application with the
Intel® Advisor
 can take substantially longer than running your target application without the
Intel® Advisor
.
Depending on an accuracy level and analyses you choose for a perspective, different overhead is added to your application execution time.
For example:
Runtime Overhead / Analysis
Survey
Characterization
Dependencies
MAP
Target application runtime with
Intel® Advisor
 compared to runtime without
Intel® Advisor
1.1x longer
2 - 55x longer
5 - 100x longer
5 - 20x longer
The following tables summarize how to minimize overhead while collecting and finalizing
Intel® Advisor
 analysis data.

Collection Controls

The following table is a summary. For more information, see Collection Controls to Minimize Analysis Overhead.
Minimization Technique
Impacted Analyses
Summary
Pause collection/Resume collection using API methods
  • Survey
  • Characterization
Pause collection:
  • C++:
    __itt_pause
  • Fortran: Use
    ITTNOTIFY
     statement to call
    ITT_PAUSE()
     subroutine
Resume collection:
  • C++:
    __itt_resume
  • Fortran: Use
    ITTNOTIFY
     statement to call
    ITT_RESUME()
     subroutine
Pause collection/Resume collection using annotations
  • Survey
  • Dependencies
Some analysis types recognize the structural annotations typically used in the
Threading
 perspective
 workflow.
Pause collection:
  • C++:
    ANNOTATE_DISABLE_COLLECTION_PUSH
  • Fortran:
    call annotate_disable_collection_push()
  • C#:
    Annotate.DisableCollectionPush()
    ;
Resume collection:
  • C++:
    ANNOTATE_DISABLE_COLLECTION_POP
  • Fortran:
    call annotate_disable_collection_pop()
  • C#:
    Annotate.DisableCollectionPop();
C# and .NET support is deprecated starting
Intel® Advisor
 2021.1.
Start target application with collection paused
  • Survey
  • Characterization
Start target application with collection paused:
  • GUI control:
    Workflow
     pane
    > Start paused
     control
  • advisor
     CLI action option:
    -start-paused
You can use different techniques to resume collection. The most common is
__itt_resume
Start target application with collection paused/Resume collection after N seconds
  • Survey
  • Characterization
GUI control:
Project Properties
Analysis Target
[Name] Analysis
Advanced
Automatically resume collection after (sec)
 checkbox
advisor
 CLI action option:
-resume-after=<integer>
Stop collection after N seconds
All
GUI control:
Project Properties
Analysis Target
[Name] Analysis
Advanced
Automatically stop collection after (sec)
 checkbox and field
advisor
 CLI action:
-stop-after=<integer>
Stop collection
All
GUI control:
Workflow
 pane
> Stop current analysis
 control and
Site Coverage
 widget
advisor
 CLI: action option:
-command=stop
Manually pause collection/Manually resume collection
  • Survey
  • Characterization
Pause collection:
  • GUI control:
    Workflow
     pane
    > Pause
     control
  • advisor
     CLI action:
    -command=pause
Resume collection:
  • GUI control:
    Workflow
     pane
    > Resume
     control
  • advisor
     CLI action:
    -command=resume
Attach to process/Detach from process
  • Survey
  • Characterization
Attach to process:
  • GUI control:
    Project Properties
    Analysis Target
    [Name] Analysis
    > Launch Application
     drop-down list
    > Attach to Process
  • advisor
     CLI action options:
    -target-pid=<unsigned integer>
     and
    -target-process=<string>
Detach from process:
  • GUI control:
    Workflow
     pane
    > Stop current analysis
     control
  • advisor
     CLI action:
    -command=detach

Loop Markup

The following table is a summary. For more information, see Loop Markup to Minimize Analysis Overhead.
Minimization Technique
Impacted
Intel Advisor
 Analyses
Summary
Select loops by ID
  • Characterization
  • Dependencies
  • Memory Access Patterns
GUI control:
Survey Report
 checkbox(es)
advisor
 CLI action option:
-mark-up-list=<string>
Select loops by source file/line
  • Characterization
  • Dependencies
  • Memory Access Patterns
GUI control:
Survey Report
 checkbox(es)
advisor
 CLI action:
-mark-up-loops
 with action option
-select=<string>
Select loops by criteria
  • Dependencies
  • Memory Access Patterns
GUI control:
Workflow
 pane
> Batch mode
 settings
advisor
 CLI: action
-mark-up-loops
 or
-collect
 with action option
-loops=<string>

Filtering

The following table is a summary. For more information, see Filtering to Minimize Analysis Overhead.
Minimization Technique
Impacted
Intel Advisor
 Analyses
Summary
Filter modules
  • Survey
  • Characterization
GUI control:
Project Properties
Analysis Target
[Name] Analysis
Modules
 options and field
advisor
 CLI: action option:
-module-filter-mode=include | exclude
 and
-module-filter=<string>

Execution Speed/Duration/Scope Properties

The following table is a summary. For more information, see Execution Speed/Duration/Scope Properties to Minimize Analysis Overhead.
Minimization Technique
Impacted
Intel Advisor
 Analyses
Summary
Change stackwalk mode from offline (after collection) to online (during collection)
Survey
GUI control:
Project Properties
Analysis Target
Survey Hotspots Analysis
Advanced
Stack unwinding mode
During collection
advisor
 CLI action option:
-stackwalk-mode=online
Disable stacks collection
  • Characterization
GUI controls:
  • Vectorization Workflow
     pane
    > Enable Roofline with Callstacks
     checkbox
  • Project Properties
    Analysis Target
    Trip Counts and FLOP Analysis
    Advanced
    Collect stacks
    checkbox
advisor
 CLI action option:
-no-stacks
 (or just ensure the CLI action option
-stacks
 is omitted from the
advisor
 command line)
Disable stitch stacks
Survey
GUI control:
Project Properties
Analysis Target
Survey Hotspots Analysis
Advanced
Stitch stacks
checkbox
advisor
CLI action option:
-no-stack-stitching
Increase sampling interval
Survey
GUI control:
Project Properties
Analysis Target
Survey Hotspots Analysis
Advanced
Sampling interval
field
advisor
 CLI action option:
interval=<integer>
Limit collected analysis data
Survey
GUI control:
Project Properties
Analysis Target
Survey Hotspots Analysis
Advanced
Collection data limit, MB
 field
advisor
 CLI action option:
-data-limit=<integer>
Limit loop call count
  • Dependencies
  • Memory Access Patterns
GUI control:
Project Properties
Analysis Target
[Name] Analysis
Advanced
Loop Call Count Limit
 field
advisor
 CLI action option:
-loop-call-count-limit=<integer>
Disable additional analysis
Survey
GUI controls:
Project Properties
Analysis Target
Survey Hotspots Analysis
Advanced
...
  • Analyze MKL loops and functions
     checkbox
  • Analyze Python loops and functions
     checkbox
  • Analyze loops that reside in non-executed code paths
     checkbox
  • Enable register spill/fill analysis
     checkbox
  • Enable static instruction mix analysis
     checkbox
advisor
 CLI action options:
  • -no-mkl-user-mode
  • -no-profile-python
  • -no-support-multi-isa-binaries
  • -no-spill-analysis
  • -no-static-instruction-mix

Miscellaneous Techniques

The following table is a summary. For more information, see Miscellaneous Techniques to Minimize Analysis Overhead.
Minimization Technique
Impacted
Intel Advisor
 Analyses
Summary
Disable cache simulation
  • Characterization
  • Memory Access Patterns
GUI controls:
  • Project Properties
    Analysis Target
    Memory Access Patterns Analysis
    Advanced
    Enable cache simulation
     checkbox
  • Project Properties
    Analysis Target
    Trip Counts and FLOP Analysis
    Advanced
    Enable cache simulation
     checkbox
advisor
 CLI action option:
-no-enable-cache-simulation
Limit reported data
Memory Access Patterns
GUI controls:
  • Project Properties
    Analysis Target
    Memory Access Patterns Analysis
    Advanced
    Report stack variables
     checkbox
  • Project Properties
    Analysis Target
    Memory Access Patterns Analysis
    Advanced
    Report heap allocated variables
     checkbox
advisor
 CLI action options:
  • -no-record-stack-frame
  • -no-record-mem-allocations
Minimize data set
All, but especially:
  • Dependencies
  • Memory Access Patterns
Minimize number of instructions executed within a loop while thoroughly exercising target application control flow paths
Temporarily disable finalization until opening result in GUI
  • Survey
  • Characterization
GUI control:
Workflow
 pane
> Cancel current analysis
 control during finalization
advisor
 CLI action option:
-no-auto-finalize

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.