User Commands prof(1)
NAME
prof - display profile data
SYNOPSIS
prof [-ChsVz] [-a | c | n | t] [-o | x] [-g | l] [-m mdata]
[prog]DESCRIPTION
The prof command interprets a profile file produced by the
monitor 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. OPTIONSThe mutually exclusive options -a, -c, -n, and -t determine
the type of sorting of the output lines:-a Sort by increasing symbol address.
-c Sort by decreasing number of calls.
-n Sort lexically by symbol name.
-t Sort by decreasing percentage of total time (default).
The mutually exclusive options -o and -x specify the print-
ing 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 mutually exclusive options -g and -l control the type of
symbols to be reported. The -l option must be used with
care; it applies the time spent in a static function to the preceding (in memory) global function, instead of giving the static function a separate entry in the report. If allSunOS 5.11 Last change: 25 Aug 2009 1
User Commands prof(1)
static functions are properly located, this feature can be very useful. If not, the resulting report may be misleading. Assume that A and B are global functions and only A calls static function S. If S is located immediately after A in the source code (that is, if S is properly located), then,with the -l option, the amount of time spent in A can
easily be determined, including the time spent in S. If,however, both A and B call S, then, if the -l option is
used, the report will be misleading; the time spent during B's call to S will be attributed to A, making it appear as if more time had been spent in A than really had. In this case, function S cannot be properly located.-g List the time spent in static (non-global) functions
separately. The -g option function is the opposite of
the -l function.
-l Suppress printing statically declared functions. If
this option is given, time spent executing in a static function is allocated to the closest global function loaded before the static function in the executable. This option is the default. It is the opposite ofthe -g function and should be used with care.
The following options may be used in any combination:-C Demangle C++ symbol names before printing them
out.-h Suppress the heading normally printed on the
report. This is useful if the report is to be processed further.-m mdata Use file mdata instead of mon.out as the input
profile file.
-s Print a summary of several of the monitoring
parameters and statistics on the standard error output.-V Print prof version information on the standard
error output.SunOS 5.11 Last change: 25 Aug 2009 2
User Commands prof(1)
-z Include all symbols in the profile range, even
if associated with zero number of calls and zero time.A single function may be split into subfunctions for profil-
ing by means of the MARK macro. See prof(5).
ENVIRONMENT VARIABLESPROFDIR The name of the file created by a profiled pro-
gram is controlled by the environment variablePROFDIR. If PROFDIR is not set, mon.out is pro-
duced in the directory current when the program terminates. If PROFDIR=string, string/pid.progname is produced, where progname consists of argv[0] with any path prefixremoved, and pid is the process ID of the pro-
gram. If PROFDIR is set, but null, no profiling
output is produced. FILESmon.out default profile file
a.out default namelist (object) fileATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| Availability | developer/object-file |
|_____________________________|_____________________________|
SEE ALSO
gprof(1), exit(2), pcsample(2), profil(2), malloc(3C),
malloc(3MALLOC), monitor(3C), attributes(5), prof(5)
NOTES If the executable image has been stripped and does not havethe .symtab symbol table, gprof reads the global dynamic
symbol tables .dynsym and .SUNW_ldynsym, if present. The
symbols in the dynamic symbol tables are a subset of the symbols that are found in .symtab. The .dynsym symbol tableSunOS 5.11 Last change: 25 Aug 2009 3
User Commands prof(1)
contains the global symbols used by the runtime linker..SUNW_ldynsym augments the information in .dynsym with local
function symbols. In the case where .dynsym is found and.SUNW_ldynsym is not, only the information for the global
symbols is available. Without local symbols, the behavior isas described for the -a option.
The times reported in successive identical runs may showvariances because of varying cache-hit ratios that result
from sharing the cache with other processes. Even if a pro-
gram seems to be the only one using the machine, hidden background or asynchronous processes may blur the data. Inrare cases, the clock ticks initiating recording of the pro-
gram counter may beat with loops in a program, grossly dis-
torting measurements. Call counts are always recorded pre-
cisely, however. Only programs that call exit or return from main areguaranteed to produce a profile file, unless a final call to
monitor is explicitly coded.The times for static functions are attributed to the preced-
ing external text symbol if the -g option is not used. How-
ever, the call counts for the preceding function are still correct; that is, the static function call counts are not added to the call counts of the external function.If more than one of the options -t, -c, -a, and -n is
specified, the last option specified is used and the user is warned.LD_LIBRARY_PATH must not contain /usr/lib as a component
when compiling a program for profiling. If LD_LIBRARY_PATH
contains /usr/lib, the program will not be linked correctlywith the profiling versions of the system libraries in
/usr/lib/libp. See gprof(1).
Functions such as mcount(), _mcount(), moncontrol(), _mon-
control(), monitor(), and _monitor() may appear in the prof
report. These functions are part of the profiling implemen-
tation and thus account for some amount of the runtime over-
head. Since these functions are not present in an unpro-
filed application, time accumulated and call counts forthese functions may be ignored when evaluating the perfor-
mance of an application.SunOS 5.11 Last change: 25 Aug 2009 4
User Commands prof(1)
64-bit profiling
64-bit profiling may be used freely with dynamically linked
executables, and profiling information is collected for the
shared objects if the objects are compiled for profiling.
Care must be applied to interpret the profile output, since
it is possible for symbols from different shared objects tohave the same name. If duplicate names are seen in the pro-
file output, it is better to use the -s (summary) option,
which prefixes a module id before each symbol that is dupli-
cated. The symbols can then be mapped to appropriate modules by looking at the modules information in the summary.If the -a option is used with a dynamically linked execut-
able, the sorting occurs on a per-shared-object basis. Since
there is a high likelihood of symbols from differed shared objects to have the same value, this results in an outputthat is more understandable. A blank line separates the sym-
bols from different shared objects, if the -s option is
given.32-bit profiling
32-bit profiling may be used with dynamically linked execut-
ables, but care must be applied. In 32-bit profiling, shared
objects cannot be profiled with prof. Thus, when a pro-
filed, dynamically linked program is executed, only the main portion of the image is sampled. This means that all time spent outside of the main object, that is, time spent in ashared object, will not be included in the profile summary;
the total time reported for the program may be less than the total time used by the program. Because the time spent in a shared object cannot be accounted for, the use of shared objects should be minimizedwhenever a program is profiled with prof. If desired, the
program should be linked to the profiled version of a
library (or to the standard archive version if no profiling
version is available), instead of the shared object to getprofile information on the functions of a library. Versions
of profiled libraries may be supplied with the system in the
/usr/lib/libp directory. Refer to compiler driver documenta-
tion on profiling.
Consider an extreme case. A profiled program dynamically
linked with the shared C library spends 100 units of time in some libc routine, say, malloc(). Suppose malloc() is called only from routine B and B consumes only 1 unit of time. Suppose further that routine A consumes 10 units oftime, more than any other routine in the main (profiled)
portion of the image. In this case, prof will conclude that
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User Commands prof(1)
most of the time is being spent in A and almost no time is being spent in B. From this it will be almost impossible to tell that the greatest improvement can be made by looking atroutine B and not routine A. The value of the profiler in
this case is severely degraded; the solution is to usearchives as much as possible for profiling.
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