# sprof - read and display shared object profiling data - man(1) - [phpMan]

> **TLDR:** Read and display shared object profiling data.
>
- Generate a flat profile and call graph (default output):
  `sprof {{path/to/library.so}} {{path/to/library.so.profile}}`
- Generate a flat profile with counts and ticks:
  `sprof {{-p|--flat-profile}} {{path/to/library.so}} {{path/to/library.so.profile}}`
- Generate a call graph:
  `sprof {{-q|--graph}} {{path/to/library.so}} {{path/to/library.so.profile}}`
- Print call pairs and their usage counts:
  `sprof {{-c|--call-pairs}} {{path/to/library.so}} {{path/to/library.so.profile}}`
- Use profile data from current directory (auto-detected by soname):
  `sprof {{path/to/library.so}}`

*Source: tldr-pages*

---

[_sprof_(1)](https://www.chedong.com/phpMan.php/man/sprof/1/markdown)                               General Commands Manual                              [_sprof_(1)](https://www.chedong.com/phpMan.php/man/sprof/1/markdown)

## NAME
       sprof - read and display shared object profiling data

## SYNOPSIS
       **sprof **[_option_]... _shared-object-path_ [_profile-data-path_]

## DESCRIPTION
       The  **sprof **command displays a profiling summary for the shared object (shared library) speci‐
       fied 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 **sprof **will attempt to deduce it using the soname of the shared
       object, looking for a file with the name _<soname>.profile_ in the current directory.

## OPTIONS
       The following command-line options specify the profile output to be produced:

### --call-pairs
### -c     
              along with the number of times each path is used.

### --flat-profile
### -p     
              and ticks.

### --graph
### -q     

       If none of the above options is specified, then the default behavior is  to  display  a  flat
       profile and a call graph.

       The following additional command-line options are available:

### --help
       **-?     **Display a summary of command-line options and arguments and exit.

### --usage
              Display a short usage message and exit.

### --version
### -V     

## STANDARDS
       GNU.

## EXAMPLES
       The  following example demonstrates the use of **sprof**.  The example consists of a main program
       that calls two functions in a shared object.  First, the code of the main program:

           $ **cat prog.c**
           #include <stdlib.h>

           void x1(void);
           void x2(void);

           int
           main(int argc, char *argv[])
           {
               x1();
               x2();
               exit(EXIT_SUCCESS);
           }

       The functions _x1_() and _x2_() are defined in the following source file that  is  used  to  con‐
       struct the shared object:

           $ **cat libdemo.c**
           #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)](https://www.chedong.com/phpMan.php/man/consumeCpu1/200000/markdown);
           }

           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)](https://www.chedong.com/phpMan.php/man/consumeCpu2/10000/markdown);
           }

       Now  we  construct the shared object with the real name _libdemo.so.1.0.1_, and the soname _lib‐_
       _demo.so.1_:

           $ **cc -g -fPIC -shared -Wl,-soname,libdemo.so.1 \**
                   **-o libdemo.so.1.0.1 libdemo.c**

       Then we construct symbolic links for the library soname and the library linker name:

           $ **ln -sf libdemo.so.1.0.1 libdemo.so.1**
           $ **ln -sf libdemo.so.1 libdemo.so**

       Next, we compile the main program, linking it against the shared object, and  then  list  the
       dynamic dependencies of the program:

           $ **cc -g -o prog prog.c -L. -ldemo**
           $ **ldd prog**
                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)

       In  order to get profiling information for the shared object, we define the environment vari‐
       able **LD_PROFILE **with the soname of the library:

           $ **export LD_PROFILE=libdemo.so.1**

       We then define the environment variable **LD_PROFILE_OUTPUT **with the pathname of the  directory
       where  profile  output  should be written, and create that directory if it does not exist al‐
       ready:

           $ **export LD_PROFILE_OUTPUT=$(pwd)/prof_data**
           $ **mkdir -p $LD_PROFILE_OUTPUT**

       **LD_PROFILE **causes profiling output to be _appended_ to the output file if it already exists, so
       we ensure that there is no preexisting profiling data:

           $ **rm -f $LD_PROFILE_OUTPUT/$LD_PROFILE.profile**

       We then run the program to produce the profiling output, which is written to a  file  in  the
       directory specified in **LD_PROFILE_OUTPUT**:

           $ **LD_LIBRARY_PATH=. ./prog**
           $ **ls prof_data**
           libdemo.so.1.profile

       We then use the **sprof -p **option to generate a flat profile with counts and ticks:

           $ **sprof -p libdemo.so.1 $LD_PROFILE_OUTPUT/libdemo.so.1.profile**
           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

       The **sprof -q **option generates a call graph:

           $ **sprof -q libdemo.so.1 $LD_PROFILE_OUTPUT/libdemo.so.1.profile**

           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]
           -----------------------------------------------

       Above  and  below, the "<UNKNOWN>" strings represent identifiers that are outside of the pro‐
       filed object (in this example, these are instances of _main()_).

       The **sprof -c **option generates a list of call pairs and the number of their occurrences:

           $ **sprof -c libdemo.so.1 $LD_PROFILE_OUTPUT/libdemo.so.1.profile**
           <UNKNOWN>                  x1                                 1
           x1                         consumeCpu1                      100
           <UNKNOWN>                  x2                                 1
           x2                         consumeCpu2                     1000

## SEE ALSO
       [**gprof**(1)](https://www.chedong.com/phpMan.php/man/gprof/1/markdown), [**ldd**(1)](https://www.chedong.com/phpMan.php/man/ldd/1/markdown), [**ld.so**(8)](https://www.chedong.com/phpMan.php/man/ld.so/8/markdown)

Linux man-pages 6.7                          2023-10-31                                     [_sprof_(1)](https://www.chedong.com/phpMan.php/man/sprof/1/markdown)