View source for Intel VTune Tutorial/Useful Tips

[[Category:Tutorials|Intel VTune Tutorials: Useful Tips]]<nowiki />
{{DISPLAYTITLE:Intel VTune Tutorial: Useful Tips}}<nowiki />
{{Syllabus Intel VTune Tutorial}}
__TOC__

This fourth tutorial of the Intel VTune series contains a loose collection of tips and tricks that did not fit anywhere else.
It covers the commandline interface, steering data taking with the ITT API, and third party tooling.

=== Video === <!--T:5-->

<youtube width="600" height="340" right>ghFn5IBzjrc</youtube>

([[Media:VTune_UsefulTips.pdf |Slides as pdf]])

=== Quiz === <!--T:5-->  
{{hidden begin 
|title = 1. How can you get help on VTunes commandline interface?}}
<quiz display=simple>
{
|type="()"}
+ <source enclose="none">vtune -help</source>
|| Correct. You can also use `vtune -help <action>` to learn more abouth other commands and `vtune -help collect <anlaysis>` to get more info on analysis types.
- <source enclose="none">vtune --help</source>
|| Not correct. The command expects a single dash!
- <source enclose="none">vtune -h</source>
|| Not correct. Although commonly used, VTune does expect a `-help` (single dash)
</quiz>
{{hidden end}}
{{hidden begin 
|title = 2. How can you get the CLI command of a configured analysis in the GUI?}}
<quiz display=simple>
{
|type="()"}
- This is not possible
|| Not correct.
- It is automatically printed in a log file
|| Not correct.
+ By pressing the 4th button at the bottom right on the "Configure Analysis" screen.
|| Correct. This is a very useful feature to explore commandline options from existing analysis configurations in the GUI.
</quiz>
{{hidden end}}
{{hidden begin 
|title = 3. What are typical causes of non-deterministic effects on profile results?}}
<quiz display=simple>
{
|type="()"}
- Quantum mechanical effects in the CPU
|| Not correct. Even though there could be random bit flips, this is not something that commonly affects performance analyses.
- Unstable system clocks
|| Not correct. Ideally the passing of time is constant.
+ Network communication, statistical nature of event based sampling, other processes competing for resources
|| Correct. It makes sense to try and get rid of most of these influence. Use a "quiet" machine and try to use a local filesystem instead of a network FS.
</quiz>
{{hidden end}}
{{hidden begin 
|title = 4. What is the ITT API?}}
<quiz display=simple>
{
|type="()"}
- A library to integrate a standalone profiler with a program during compilation
|| Not correct. You still need VTune to profile your application.
- An interactive VTune tutorial that automatically uses your program as an example
|| Not correct.
+ A library for instrumentation and tracing. Allows for steering profile collection from the source code
|| Correct. This can be very useful to only measure interesting sections of your program!
</quiz>
{{hidden end}}