User Guide

Contents

Window: Top-down Tree

Use the
Top-down Tree
window to explore the call sequence flow of the application and analyze the time spent in each program unit and on its callees.
To access this pane:
Run a performance analysis type collecting stacks and click the
Top-down Tree
tab when the collection result opens.
Top-Down Tree Window
Function Stack
The
Function Stack
column represents call sequences (stacks) detected during collection phase starting from the application root (usually, the
main()
function). The time value for a row is equal to the sum of all the nested items from that row. Use this data to see the impact of program units together with their callees. This type of investigation is known as a
top-down analysis
.
In this example above, the hotspot
thread_video
function has three callees, where
rt_renderscene
is the first candidate for optimization.
The call stacks are always available for the results of the user-mode sampling and tracing collection. They are also available for the results of the hardware event-based sampling collection, if you enabled the
Collect stacks
option during the analysis configuration. Otherwise, the
Function Stack
column for the event-based sampling results shows a flat list of the functions.
<
Performance metrics
>
Each data column in the
Top-Down Tree
grid corresponds to a performance metric. The list of performance metrics varies with the analysis type and selected viewpoint. In the
Top-down Tree
window, the
Intel® VTune™
Profiler
provides two types of metrics:
  • Self
    metrics show performance data collected within particular procedures and functions.
  • Total
    metrics show performance data collected within functions AND children (callees).
By default, all program units are sorted in a descending order by the metric values in the first column (for example,
CPU Time: Total
) providing the most performance-critical program units first. You may click a column header to re-sort the table by the required metric.
Mouse over a column header to see a metric description.

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