PROF(1) SysV PROF(1)
NAME
prof - display profile data
SYNOPSIS
prof [-tcan] [-ox] [-g] [-z] [-h] [-s] [-m mdata]" [prog]
DESCRIPTION
The prof command interprets a profile file produced by the monitor(3C)
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. The mutually exclusive options o and x
specify the printing of the address of each symbol monitored. All other
options may be used in any combination.
A program creates a profile file if it has been loaded with the -p option
of cc(1). This option to the cc command arranges for calls to
monitor(3C) 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(5)].
OPTIONS
-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.
-o Print each symbol address (in octal) along with the symbol
name.
-x Print each symbol address (in hexadecimal) along with the
symbol name.
-g Include non-global symbols (static functions).
-z Include all symbols in the profile range [see
monitor(3C)], 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.
FILES
mon.out for profile
a.out for namelist
WARNINGS
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, i.e., the static function call
counts are not added in with the call counts of the external function.
CAVEATS
Only programs that call exit(2) 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(1) 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(3C) 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.
SEE ALSO
cc(1), exit(2), profil(2), monitor(3C), prof(5).