Linux benchmark for CI20-os demonstration

benchmark.c

#include <sys/time.h>
#include <inttypes.h>
#include <stdio.h>

uint32_t ms(struct timeval *from, struct timeval *to)
{
	uint32_t from_ms, to_ms;

	from_ms = (from->tv_sec * 1000) + (from->tv_usec / 1000);
	to_ms = (to->tv_sec * 1000) + (to->tv_usec / 1000);

	return to_ms - from_ms;
}

int main(int argc, char **argv)
{
	int run;
	struct timeval prev, cur;

	for(run = 0; run < 3; run ++) {
		volatile uint32_t i;
		gettimeofday(&prev, 0);

		for(i = 0; i < 0xfffffff; i++)
			;

		gettimeofday(&cur, 0);

		printf("%04x\n", ms(&prev, &cur));
	}

	return 0;
}