Name
prof - display profile data
Syntax
prof [-tcan] [-ox] [-g] [-z] [-h] [-s] [-m mdata] [prog]
Description
The prof command interprets a profile file produced by the
monitor(S) function. The symbol table in the object file
prog (a.out by default) is read and correlated with a
profile file (mon.out by default). For each external text
symbol the percentage of time spent executing between the
address of that symbol and the address of the next is
printed, together with the number of times that function was
called and the average number of milliseconds per call.
The mutually exclusive options t, c, a, and n determine the
type of sorting of the output lines:
-t Sort by decreasing percentage of total time (default).
-c Sort by decreasing number of calls.
-a Sort by increasing symbol address.
-n Sort lexically by symbol name.
The mutually exclusive options o and x specify the printing
of the address of each symbol monitored:
-o Print each symbol address (in octal) along with the
symbol name.
-x Print each symbol address (in hexadecimal) along with
the symbol name.
The following options may be used in any combination:
-g Include non-global symbols (static functions).
-z Include all symbols in the profile range (see
monitor(S)), even if associated with zero number of
calls and zero time.
-h Suppress the heading normally printed on the report.
(This is useful if the report is to be processed
further.)
-s Print a summary of several of the monitoring parameters
and statistics on the standard error output.
-m mdata
Use file mdata instead of mon.out as the input profile
file.
A program creates a profile file if it has been loaded with
the -p option of cc(CP). This option to the cc command
arranges for calls to monitor(S) at the beginning and end of
execution. It is the call to monitor at the end of
execution that causes a profile file to be written. The
number of calls to a function is tallied if the -p option
was used when the file containing the function was compiled.
The name of the file created by a profiled program is
controlled by the environment variable PROFDIR. If PROFDIR
does not exist, ``mon.out'' is produced in the directory
that is current when the program terminates. If PROFDIR =
string, ``string/pid.progname'' is produced, where progname
consists of argv[0] with any path prefix removed, and pid is
the program's process id. If PROFDIR is the null string, no
profiling output is produced.
A single function may be split into subfunctions for
profiling by means of the MARK macro (see prof(M)).
Files
mon.out for profile
a.out for namelist
See Also
cc(CP), exit(S), profil(S), monitor(S), prof(M).
Warning
The times reported in successive identical runs may show
variances of 20% or more, because of varying cache-hit
ratios due to sharing of the cache with other processes.
Even if a program seems to be the only one using the
machine, hidden background or asynchronous processes may
blur the data. In rare cases, the clock ticks initiating
recording of the program counter may ``beat'' with loops in
a program, grossly distorting measurements.
Call counts are always recorded precisely.
The times for static functions are attributed to the
preceding external text symbol if the -g option is not used.
However, the call counts for the preceding function are
still correct (that is, the static function call counts are
not added in with the call counts of the external function).
Notes
If you are using XENIX binaries, please refer to the manual
entry for this utility in the XENIX Development Guide for
information on the appropriate usage with XENIX binaries.
Only programs that call exit(S) or return from main will
cause a profile file to be produced, unless a final call to
monitor is explicitly coded.
The use of the -p option to cc(CP) to invoke profiling
imposes a limit of 600 functions that may have call counters
established during program execution. For more counters you
must call monitor(S) directly. If this limit is exceeded,
other data will be overwritten and the mon.out file will be
corrupted. The number of call counters used will be
reported automatically by the prof command whenever the
number exceeds 5/6 of the maximum.
Standards Conformance
prof is conformant with:
AT&T SVID Issue 2, Select Code 307-127;
and The X/Open Portability Guide II of January 1987.
(printed 6/18/89)