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diff --git a/man1/sprof.1 b/man1/sprof.1 new file mode 100644 index 0000000..186dad4 --- /dev/null +++ b/man1/sprof.1 @@ -0,0 +1,272 @@ +.\" Copyright (C) 2014 Michael Kerrisk <mtk.manpages@gmail.com> +.\" +.\" SPDX-License-Identifier: Linux-man-pages-copyleft +.\" +.TH sprof 1 2023-05-03 "Linux man-pages 6.05.01" +.SH NAME +sprof \- read and display shared object profiling data +.SH SYNOPSIS +.nf +.BR sprof " [\fIoption\fP]... \fIshared-object-path\fP \ +[\fIprofile-data-path\fP]" +.fi +.SH DESCRIPTION +The +.B sprof +command displays a profiling summary for the +shared object (shared library) specified as its first command-line argument. +The profiling summary is created using previously generated +profiling data in the (optional) second command-line argument. +If the profiling data pathname is omitted, then +.B sprof +will attempt to deduce it using the soname of the shared object, +looking for a file with the name +.I <soname>.profile +in the current directory. +.SH OPTIONS +The following command-line options specify the profile output +to be produced: +.TP +.BR \-c ", " \-\-call\-pairs +Print a list of pairs of call paths for the interfaces exported +by the shared object, +along with the number of times each path is used. +.TP +.BR \-p ", " \-\-flat\-profile +Generate a flat profile of all of the functions in the monitored object, +with counts and ticks. +.TP +.BR \-q ", " \-\-graph +Generate a call graph. +.PP +If none of the above options is specified, +then the default behavior is to display a flat profile and a call graph. +.PP +The following additional command-line options are available: +.TP +.BR \-? ", " \-\-help +Display a summary of command-line options and arguments and exit. +.TP +.B \-\-usage +Display a short usage message and exit. +.TP +.BR \-V ", " \-\-version +Display the program version and exit. +.SH STANDARDS +GNU. +.SH EXAMPLES +The following example demonstrates the use of +.BR sprof . +The example consists of a main program that calls two functions +in a shared object. +First, the code of the main program: +.PP +.in +4n +.EX +$ \fBcat prog.c\fP +#include <stdlib.h> +\& +void x1(void); +void x2(void); +\& +int +main(int argc, char *argv[]) +{ + x1(); + x2(); + exit(EXIT_SUCCESS); +} +.EE +.in +.PP +The functions +.IR x1 () +and +.IR x2 () +are defined in the following source file that is used to +construct the shared object: +.PP +.in +4n +.EX +$ \fBcat libdemo.c\fP +#include <unistd.h> +\& +void +consumeCpu1(int lim) +{ + for (unsigned int j = 0; j < lim; j++) + getppid(); +} +\& +void +x1(void) { + for (unsigned int j = 0; j < 100; j++) + consumeCpu1(200000); +} +\& +void +consumeCpu2(int lim) +{ + for (unsigned int j = 0; j < lim; j++) + getppid(); +} +\& +void +x2(void) +{ + for (unsigned int j = 0; j < 1000; j++) + consumeCpu2(10000); +} +.EE +.in +.PP +Now we construct the shared object with the real name +.IR libdemo.so.1.0.1 , +and the soname +.IR libdemo.so.1 : +.PP +.in +4n +.EX +$ \fBcc \-g \-fPIC \-shared \-Wl,\-soname,libdemo.so.1 \e\fP + \fB\-o libdemo.so.1.0.1 libdemo.c\fP +.EE +.in +.PP +Then we construct symbolic links for the library soname and +the library linker name: +.PP +.in +4n +.EX +$ \fBln \-sf libdemo.so.1.0.1 libdemo.so.1\fP +$ \fBln \-sf libdemo.so.1 libdemo.so\fP +.EE +.in +.PP +Next, we compile the main program, linking it against the shared object, +and then list the dynamic dependencies of the program: +.PP +.in +4n +.EX +$ \fBcc \-g \-o prog prog.c \-L. \-ldemo\fP +$ \fBldd prog\fP + linux\-vdso.so.1 => (0x00007fff86d66000) + libdemo.so.1 => not found + libc.so.6 => /lib64/libc.so.6 (0x00007fd4dc138000) + /lib64/ld\-linux\-x86\-64.so.2 (0x00007fd4dc51f000) +.EE +.in +.PP +In order to get profiling information for the shared object, +we define the environment variable +.B LD_PROFILE +with the soname of the library: +.PP +.in +4n +.EX +$ \fBexport LD_PROFILE=libdemo.so.1\fP +.EE +.in +.PP +We then define the environment variable +.B LD_PROFILE_OUTPUT +with the pathname of the directory where profile output should be written, +and create that directory if it does not exist already: +.PP +.in +4n +.EX +$ \fBexport LD_PROFILE_OUTPUT=$(pwd)/prof_data\fP +$ \fBmkdir \-p $LD_PROFILE_OUTPUT\fP +.EE +.in +.PP +.B LD_PROFILE +causes profiling output to be +.I appended +to the output file if it already exists, +so we ensure that there is no preexisting profiling data: +.PP +.in +4n +.EX +$ \fBrm \-f $LD_PROFILE_OUTPUT/$LD_PROFILE.profile\fP +.EE +.in +.PP +We then run the program to produce the profiling output, +which is written to a file in the directory specified in +.BR LD_PROFILE_OUTPUT : +.PP +.in +4n +.EX +$ \fBLD_LIBRARY_PATH=. ./prog\fP +$ \fBls prof_data\fP +libdemo.so.1.profile +.EE +.in +.PP +We then use the +.B sprof \-p +option to generate a flat profile with counts and ticks: +.PP +.in +4n +.EX +$ \fBsprof \-p libdemo.so.1 $LD_PROFILE_OUTPUT/libdemo.so.1.profile\fP +Flat profile: +\& +Each sample counts as 0.01 seconds. + % cumulative self self total + time seconds seconds calls us/call us/call name + 60.00 0.06 0.06 100 600.00 consumeCpu1 + 40.00 0.10 0.04 1000 40.00 consumeCpu2 + 0.00 0.10 0.00 1 0.00 x1 + 0.00 0.10 0.00 1 0.00 x2 +.EE +.in +.PP +The +.B sprof \-q +option generates a call graph: +.PP +.in +4n +.EX +$ \fBsprof \-q libdemo.so.1 $LD_PROFILE_OUTPUT/libdemo.so.1.profile\fP +\& +index % time self children called name +\& + 0.00 0.00 100/100 x1 [1] +[0] 100.0 0.00 0.00 100 consumeCpu1 [0] +\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\- + 0.00 0.00 1/1 <UNKNOWN> +[1] 0.0 0.00 0.00 1 x1 [1] + 0.00 0.00 100/100 consumeCpu1 [0] +\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\- + 0.00 0.00 1000/1000 x2 [3] +[2] 0.0 0.00 0.00 1000 consumeCpu2 [2] +\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\- + 0.00 0.00 1/1 <UNKNOWN> +[3] 0.0 0.00 0.00 1 x2 [3] + 0.00 0.00 1000/1000 consumeCpu2 [2] +\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\- +.EE +.in +.PP +Above and below, the "<UNKNOWN>" strings represent identifiers that +are outside of the profiled object (in this example, these are instances of +.IR main() ). +.PP +The +.B sprof \-c +option generates a list of call pairs and the number of their occurrences: +.PP +.in +4n +.EX +$ \fBsprof \-c libdemo.so.1 $LD_PROFILE_OUTPUT/libdemo.so.1.profile\fP +<UNKNOWN> x1 1 +x1 consumeCpu1 100 +<UNKNOWN> x2 1 +x2 consumeCpu2 1000 +.EE +.in +.SH SEE ALSO +.BR gprof (1), +.BR ldd (1), +.BR ld.so (8) |