memusage - Man Page

memusage [option]... program [programoption]...

memusage is a bash script which profiles memory usage of the program, program. It preloads the libmemusage.so library into the caller's environment (via the LD_PRELOAD environment variable; see ld.so(8)). The libmemusage.so library traces memory allocation by intercepting calls to malloc(3), calloc(3), free(3), and realloc(3); optionally, calls to mmap(2), mremap(2), and munmap(2) can also be intercepted.

memusage can output the collected data in textual form, or it can use memusagestat(1) (see the -p option,  below) to create a PNG file containing graphical representation of the collected data.

-n name, --progname=name

Name of the program file to profile.

-p file, --png=file

Generate PNG graphic and store it in file.

-d file, --data=file

Generate binary data file and store it in file.

-u, --unbuffered

Do not buffer output.

-b size, --buffer=size

Collect size entries before writing them out.

--no-timer

Disable timer-based (SIGPROF) sampling of stack pointer value.

-m, --mmap

Also trace mmap(2), mremap(2), and munmap(2).

-?, --help

Print help and exit.

--usage

Print a short usage message and exit.

-V, --version

Print version information and exit.

The following options apply only when generating graphical output:

-t, --time-based

Use time (rather than number of function calls) as the scale for the X axis.

-T, --total

Also draw a graph of total memory use.

--title=name

Use name as the title of the graph.

-x size, --x-size=size

Make the graph size pixels wide.

-y size, --y-size=size

Make the graph size pixels high.

The exit status of memusage is equal to the exit status of the profiled program.

To report bugs, see http://www.gnu.org/software/libc/bugs.html

Below is a simple program that reallocates a block of memory in cycles that rise to a peak before then cyclically reallocating the memory in smaller blocks that return to zero. After compiling the program and running the following commands, a graph of the memory usage of the program can be found in the file memusage.png:

$ memusage --data=memusage.dat ./a.out
...
Memory usage summary: heap total: 45200, heap peak: 6440, stack peak: 224
        total calls  total memory  failed calls
 malloc|         1           400             0
realloc|        40         44800             0  (nomove:40, dec:19, free:0)
 calloc|         0             0             0
   free|         1           440
Histogram for block sizes:
  192-207             1   2% ================
...
 2192-2207            1   2% ================
 2240-2255            2   4% =================================
 2832-2847            2   4% =================================
 3440-3455            2   4% =================================
 4032-4047            2   4% =================================
 4640-4655            2   4% =================================
 5232-5247            2   4% =================================
 5840-5855            2   4% =================================
 6432-6447            1   2% ================
$ memusagestat memusage.dat memusage.png

#include <stdio.h>
#include <stdlib.h>

#define CYCLES 20

int
main(int argc, char *argv[])
{
    int i, j;
    size_t size;
    int *p;

    size = sizeof(*p) * 100;
    printf("malloc: %zu\n", size);
    p = malloc(size);

    for (i = 0; i < CYCLES; i++) {
        if (i < CYCLES / 2)
            j = i;
        else
            j--;

        size = sizeof(*p) * (j * 50 + 110);
        printf("realloc: %zu\n", size);
        p = realloc(p, size);

        size = sizeof(*p) * ((j + 1) * 150 + 110);
        printf("realloc: %zu\n", size);
        p = realloc(p, size);
    }

    free(p);
    exit(EXIT_SUCCESS);
}

memusagestat(1), mtrace(1), ld.so(8)

memusagestat(1), mtrace(1).