User and Reference Guide

Contents

Defining and Recording Functions or Regions

Intel® Trace Analyzer can display and analyze general (properly nested) state changes, relating to function calls, entry/exit to/from code regions and other events occurring in a process. Intel® Trace Analyzer implements a two-level model of states: a state is referred to by an activity name that identifies a group of states, and the state (or symbol) name that references a particular state in that group. For instance, all MPI functions are part of the activity MPI, and each one is identified by its function name, for instance
MPI_Send
for C and for Fortran.
The Intel® Trace Collector API allows the user to define arbitrary activities and symbols and to record entry and exit to/from them. In order to reduce the instrumentation overhead, symbols are referred to by integer handles that can be managed automatically (using the
VT_funcdef()
interface) or assigned by the user (using the old
VT_symdef()
function). All activities and symbols are defined by each process that uses them, but it is not necessary to define them consistently on all processes (see
UNIFY-SYMBOLS
).
Optionally, information about source locations can be recorded for state enter and exit events by passing a non-null location handle to the
VT_enter()
/
VT_leave()
or
VT_beginl()
/
VT_endl()
functions.

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.