User Guide

Contents

Self Time and Total Time

Intel® VTune™
Profiler
can calculate analysis-independent time spent within particular procedures and functions and within children (callees). This is the information for Self and Total time, respectively. The
Bottom-up
window shows only Self time. The
Top-down Tree
window and
Source
/
Assembly
window show Self time and Total time.

Self Time

Self time is the time spent in a particular program unit. For example, Self time for a source line shows the time the application spent at this particular source line. Self time can help you understand the impact that a function has on the program. Investigating the impact of single functions is also known as bottom-up analysis.
For example, in a single-threaded program with negligible Wait time, the Self time for the function
foo()
is 10% of the program CPU time. If you optimize
foo()
so that it is twice as fast, the Elapsed time for the program improves by 5%.
The impact of Self time on the Elapsed time of a parallel application depends on the utilization of different threads. Reducing the time that a given function runs to zero may have no impact on the Elapsed time of the application

Total Time

Total time is the accumulated time that a program unit incurs. For functions, Total time includes Self time of the function itself and Self time of all functions that were called from that function. Total time enables a high-level understanding of how time is spent in the application. Investigating the impact of functions together with their callees is also known as top-down analysis.

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