New analysis type names: Basic Hotspots and Advanced Hotspots

After upgrading to Intel® VTune™ Amplifier XE 2013 update 9 you will find a bunch of new features. Among many new things, you may notice that two old and well-known things are missing – “Hotspots” and “Lightweight Hotspots” analysis types. 

No worries – they were not dropped. They were just renamed to “Basic Hotspots” and “Advanced Hotspots” respectively, though with some interface changes.

 
This change was made to reflect the analysis purpose more clearly and to improve usability. The “Hotspots” analysis type is now “Basic Hotspots” because it provides a general performance profile at the user level. And the former “Lightweight Hotspots” analysis type uses PMU counters, can dive into the system level, and has more control options, so it can give more detailed information. In terms of usage, it is more advanced, and this is now stated in its name.
 

Hotspots -> Basic Hotspots

This change is just a new name, no more than that. Everything works the same as the former Hotspots. The command line name was not even changed:
 
amplxe-cl -collect hotspots -- find_hotspots.exe
 

Lightweight Hotspots -> Advanced Hotspots

The new Advanced Hotspots uses the same collection techniques as the former Lightweight Hotspots, but the interface has changed:

 

 

 

The checkboxes “Collect stacks” and “Estimate call counts” are replaced by a radio button switch. This is more straightforward. For example, call count collection is impossible without collecting stacks, so there is no need for fully independent control of calculating call counts.

 

  • Hotspots – the same as “Lightweight Hotspots” with default settings, no stack and call count information is collected.
  • Hotspots, stacks and context switches – the same as “Lightweight Hotspots” with enabled “Collect stacks” option and disabled “Estimate call counts”.
  • Hotspots, call counts, stacks and context switches – the same as “Lightweight Hotspots” with both “Collect stacks” and “Estimate call counts” options enabled.
The “Hotspots” option has the lowest overhead, lower than “Basic Hotspots”. The second option adds stack information and introduces more overhead. And the third option with call counts produces even more overhead than option two.
 
The “Event mode” switch was previously available for custom analyses only, now it appears on the main page. The “Analyze Processor Graphics” and “Analyze DirectX pipeline events” options are new, but they refer to the profiling Intel® HD Graphics feature, they are not specific to the reorganized analysis type.
 
The “Details” section provides a summary of your analysis configuration. You can see the usual check boxes there.

 

 
 

 

Command line changes

Advanced Hotspots has a new name in the command line as well. Moreover, knob options were also changed. The good news is that the old command-line-interface (CLI) options still work, so your existing scripts will not break. The three examples of command lines below have identical effects, the first being “new style” and the second “old style.” All work with the latest VTune Amplifier XE update.
 
1. Advanced Hotspots with default settings
 
Graphical User Interface (GUI)

 

CLI
New: amplxe-cl -collect advanced-hotspots -- find_hotspots.exe
Old (still works): amplxe-cl -collect lightweight-hotspots -- find_hotspots.exe
 
2. Advanced Hotspots with collecting stack information
 
GUI

 

CLI
New: amplxe-cl -collect advanced-hotspots -knob collection-detail=stack-sampling -- find_hotspots.exe 
Old (still works):  amplxe-cl -collect lightweight-hotspots -knob enable-stack-collection=true -- find_hotspots.exe
 
3. Advanced Hotspots with collecting stack and call count information
 
GUI

 

CLI
New: amplxe-cl -collect advanced-hotspots -knob collection-detail=stack-and-callcount -- find_hotspots.exe
Old (still works):  amplxe-cl -collect lightweight-hotspots -knob enable-stack-collection=true -knob enable-call-counts=true -- find_hotspots.exe
 

Summary

New analysis types described in this article are the result of interface changes intended to improve usability. “Basic Hotspots” is just a new name for the “Hotspots” analysis type. “Advanced Hotspots” provides the same capabilities as “Lightweight Hotspots,” with a renewed GUI and CLI interface. At the same time, backward compatibility is maintained and all old command line options still work in the same way as before in VTune Amplifier XE 2013 update 9.
 
 
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