User Guide

Contents

Finding Time Regions of Low Concurrency and Their Cause

  1. Run the trace collector.
  2. In the
    Execution Trace Views
    tab, inspect the node concurrency histogram for regions in red, which indicate low concurrency.
    node concurrency histogram
  3. Zoom in to a red region to inspect the data at a higher resolution and provide a better idea as to how concurrency varies over time.
    zoom into the node concurrency histogram for details
  4. Select a point in the chart where the concurrency is low to highlight the relevant node(s). Hover the mouse over the highlighted node to identify the node name.
Because the analysis tool does not have built-in symbol resolution, the determination of the C++ class of the body executed by a node must be explicitly encoded into the application. Explicit encoding affects the
Name and/or object_name
fields in the
Node Properties
tab. For example:
tbb::flow::graph g; . . . tbb::flow::source_node<int> s_node (g, source_node_body(), false); #if TBB_PREVIEW_FLOW_GRAPH_TRACE s_node.set_name(“My Source Node”); #endif
This coding enables node annotation with the specified string during trace collection, and the annotation appears when you hover the mouse over the node.
The
set_name
functions are only available when the
TBB_PREVIEW_FLOW_GRAPH_TRACE
macro is defined at compile-time.

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