User Guide

Contents

hotspots
Command Line Analysis

Hotspots analysis helps understand application flow and identify sections of code that get a lot of execution time (
hotspots
). A large number of samples collected at a specific process, thread, or module can imply high processor utilization and potential performance bottlenecks. Some hotspots can be removed, while other hotspots are fundamental to the application functionality and cannot be removed.
Intel® VTune™
Profiler
creates a list of functions in your application ordered by the amount of time spent in each function. It also can be configured to capture the call stacks for each of these functions so you can see how the hot functions are called.
Use the
-knob
option to specify a collection mode for the Hotspots analysis:
  • sampling-mode=sw
    - User-Mode Sampling (default) used for profiling:
    • Targets running longer than a few seconds
    • A single process or a process-tree
    • Python and Intel runtimes
  • sampling-mode=hw
    - Hardware Event-Based Sampling used for profiling:
    • Targets running less than a few seconds
    • All processes on a system, including the kernel

Syntax

vtune
-collect hotspots -knob <
knobName=knobValue
> [--] <
target
>
Knobs:
,
enable-stack-collection
,
sampling-interval, enable-characterization-insights
For the most current information on available knobs (configuration options) for the Hotspots analysis, enter:
vtune
-help collect hotspots
Example
This example shows how to run the Hotspots analysis in the
user-mode sampling
mode for a Linux*
myApplication
:
vtune
-collect hotspots -knob sampling-mode=sw -- /home/test/myApplication
This example shows how to run the Hotspots analysis in the
hardware event-based sampling
mode for a Windows*
myApplication
:
vtune
-collect hotspots -knob sampling-mode=hw -knob sampling-interval=1 -- C:\test\myApplication.exe
The
hardware event-based sampling
mode replaced the
advanced-hotspots
analysis starting with VTune Amplifier 2019.

What's Next

When the data collection is complete, do one of the following to view the result:

Product and Performance Information

1

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804