bench_pc

bench.sh

#!/bin/bash

docker run --rm -v $PWD:/a -w /a buildpack-deps:buster cc bench_pc.c $*

time docker run --rm -v $PWD:/a debian:buster-slim /a/a.out
time docker run --rm -v $PWD:/a --privileged debian:buster-slim /a/a.out

bench_pc.c

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

#define NB_PASSES 10000
#define NB_ELEMS (500 * 64)

void bench_pc_ram_int();
void bench_pc_ram_float();

static float *tab_float;
static int *tab_int;

int main()
{
    int i;
    tab_int = malloc(NB_ELEMS * sizeof(int));
    tab_float = malloc(NB_ELEMS * sizeof(float));

    for (i = 0; i < NB_PASSES; i++)
    {
        bench_pc_ram_int();
        bench_pc_ram_float();

        if ((NB_PASSES < 100) || (i % (NB_PASSES / 100) == 0))
        {
            printf(".");
            fflush(NULL);
        }
    }

    printf("\n");
}

void bench_pc_ram_int()
{
    int i;

    tab_int[0] = 0;
    for (i = 1; i < NB_ELEMS; i++)
    {
        tab_int[i] = tab_int[i - 1] + 1;
    }

    for (i = 1; i < NB_ELEMS / 2; i++)
    {
        tab_int[i] = tab_int[i] + tab_int[NB_ELEMS / 2 + i];
    }

    for (i = 1; i < NB_ELEMS / 4; i++)
    {
        tab_int[i] = tab_int[i] * tab_int[NB_ELEMS / 4 + i];
    }

    for (i = 1; i < NB_ELEMS / 16; i++)
    {
        tab_int[i] = tab_int[i] / tab_int[NB_ELEMS / 16 + i];
    }

    for (i = 1; i < NB_ELEMS / 32; i++)
    {
        tab_int[i] = tab_int[i] - tab_int[NB_ELEMS / 32 + i];
    }

    for (i = 1; i < NB_ELEMS / 64; i++)
    {
        tab_int[i] = -tab_int[i] + tab_int[NB_ELEMS / 64 + i];
    }
}

void bench_pc_ram_float()
{
    int i;

    tab_float[0] = 0;
    for (i = 1; i < NB_ELEMS; i++)
    {
        tab_float[i] = tab_float[i - 1] + 0.1;
    }

    for (i = 1; i < NB_ELEMS / 2; i++)
    {
        tab_float[i] = tab_float[i] + tab_float[NB_ELEMS / 2 + i];
    }

    for (i = 1; i < NB_ELEMS / 4; i++)
    {
        tab_float[i] = tab_float[i] * tab_float[NB_ELEMS / 4 + i];
    }

    for (i = 1; i < NB_ELEMS / 16; i++)
    {
        tab_float[i] = tab_float[i] / tab_float[NB_ELEMS / 16 + i];
    }

    for (i = 1; i < NB_ELEMS / 32; i++)
    {
        tab_float[i] = tab_float[i] - tab_float[NB_ELEMS / 32 + i];
    }

    for (i = 1; i < NB_ELEMS / 64; i++)
    {
        tab_float[i] = -tab_float[i] + tab_float[NB_ELEMS / 64 + i];
    }
}

benchperf.sh

#!/bin/bash

cp bench_pc.c /tmp
docker run -ti --rm -v /tmp:/a -w /a builder cc bench_pc.c $*

docker create --name perf_d -ti -v /tmp:/a debian:buster-slim /a/a.out
docker create --name perf_p -ti -v /tmp:/a --privileged debian:buster-slim /a/a.out

echo
echo "NATIVE"
time ./a.out

echo
echo "DOCKER"
time docker start -i perf_d

echo
echo "PRIVILEGED"
time docker start -i perf_p


echo
echo "NATIVE"
./a.out &                 perf record -a -o perf_n.data -- sleep 15

echo
echo "DOCKER"
docker start -i perf_d &  perf record -a -o perf_d.data -- sleep 15

echo
echo "PRIVILEGED"
docker start -i perf_p &  perf record -a -o perf_p.data -- sleep 15

docker rm perf_d
docker rm perf_p