malloc of large objects

foo.c

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

enum {
	ALLOC_STREAK_MAX = 1024,
	ALLOC_MIN = 1024 * 1024,
	ALLOC_MAX = 1024 * 1024 * 128,
	ITERATIONS = 1024,
};

int allocations = 0;

void *ptrs[ALLOC_STREAK_MAX];
size_t sizes[ALLOC_STREAK_MAX];

void
streak(int n_allocs)
{
	for (int i = 0; i < n_allocs; i++) {
		int size = rand() % ALLOC_MAX;
		if (size < ALLOC_MIN)
			size += ALLOC_MIN;
		sizes[i] = size;

		ptrs[i] = malloc(size);
		allocations++;
	}
	for (int i = 0; i < n_allocs; i++) {
		free(ptrs[i]);
	}
}

int main()
{
	int seed = time(NULL);
	printf("seed: %d\n", seed);
	srand(seed);
	for (int i = 0; i < ITERATIONS; i++)
		streak(rand() % ALLOC_STREAK_MAX);
	printf("total allocations: %d\n", allocations);
}

shell.log

kostja@atlas ~ % time ./a.out 
seed: 1502978000
total allocations: 509347
./a.out  0,46s user 6,86s system 99% cpu 7,314 total