HP-UX Reference (11i v1 05/09) - 1 User Commands A-M (vol 1)

g
gprof(1) gprof(1)
NAME
gprof - display call graph profile data
SYNOPSIS
gprof [options ][a.out [gmon.out ]... ]
DESCRIPTION
The
gprof command produces an execution profile of C++, C and FORTRAN programs. The effect of
called routines is incorporated into the profile of each caller. Profile data is taken from the call graph
profile file (gmon.out default) that is created by programs compiled with the
-G option of aCC, cc, and
f90. The -G option also links in versions of the library routines that are compiled for profiling.
On Itanium(R)-based systems,
gprof supports multiple shared libraries profiling. On PA-RISC systems,
gprof supports single shared library profiling. For details on this see the section below, Shared Library
Profiling.
The symbol table for the load modules being profiled are read and correlated with the call graph profile file
(
gmon.out). To have the full call graph, no load module symbol table may be chopped; that is, no com-
piles may use the -x option. If more than one profile file is specified,
gprof output shows the sum of the
profile information in the given profile files.
First, a flat profile is given, similar to that provided by
prof (see prof(1)). This listing gives the total exe-
cution times and call counts for each function in the load modules being profiled, sorted by decreasing time.
On Itanium-based systems, the module index is also reported for each function signifying the load module
in which the function is defined.
Next, these times are propagated along the edges of the call graph.
gprof discovers all cycles in the call
graph. All calls made into the cycle share the time of that cycle. A second listing shows the functions
sorted according to the time they represent including the time of their call graph descendants. Below each
function entry is shown its (direct) call graph children, and how their times are propagated to this function.
A similar display above the function shows how the time of this function and the time of its descendants are
propagated to its (direct) call graph parents.
Cycles are also shown, with an entry for the cycle as a whole and a listing of the members of the cycle, each
with their contributions to the time and call counts of the cycle.
On Itanium-based systems, in the end a mapping of all module indices to module names is given. The
modules not being profiled are reported at the top of output.
Shared Library Profiling
Support for gprof profiling of shared libraries is available both on 32-bit and 64-bit Itanium-based sys-
tems. On PA-RISC systems only 32-bit shared library profiling is supported.
On Itanium-based systems
The environment variable LD_PROFILE determines what load modules get profiled. Set
LD_PROFILE=ALL to profile all load modules; that is, report timing and call count information for
all loadable modules, including a.out. Set LD_PROFILE= ldm1:ldm2 to profile only loadable
modules ldm1 and ldm2. ldm1 and ldm2 are not full pathnames; they are the names recorded in the
executables, which can be displayed using chatr(1). If LD_PROFILE is not set, gprof behaves as
though LD_PROFILE=ALL.
The environment variable LD_PROFILEBUCKET_SIZE controls the size of profiling counters. The
acceptable value for this variable is 16 or 32. Counter size can also be specified at compile time using
the +profilebucketsize option. The runtime value overrides the compile time value. A warn-
ing is issued if the counter size is set to a value other than 16 or 32; in this case the value specified at
compile time is used. The default value of the counter is 16, which is used if a valid value is not
specified. See the description of the +profilebucketsize option in cc(1) for more details.
At program termination the
gprof library dumps all profiling information on a per-module basis in
gmon.out, which the gprof command reads and matches to corresponding functions in the load
modules.
On PA-RISC systems
To profile a shared library, set the environment variable LD_PROFILE to the path of the shared
library to be profiled. (See HP-UX Linker and Libraries Online User’s Guide for details.) Do not use
the -G option to compile programs for shared library profiling. Do not link the executable gcrt0.o
HP-UX 11i Version 1: September 2005 − 1 − Hewlett-Packard Company Section 1−−347