/*

* Copyright (c) 2016, Stefan Lankes, RWTH Aachen University

* All rights reserved.

*

* Redistribution and use in source and binary forms, with or without

* modification, are permitted provided that the following conditions are met:

* * Redistributions of source code must retain the above copyright

* notice, this list of conditions and the following disclaimer.

* * Redistributions in binary form must reproduce the above copyright

* notice, this list of conditions and the following disclaimer in the

* documentation and/or other materials provided with the distribution.

* * Neither the name of the University nor the names of its contributors

* may be used to endorse or promote products derived from this

* software without specific prior written permission.

*

* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND

* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

* DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY

* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES

* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND

* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS

* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

*/

#ifndef __hermit__

#define _GNU_SOURCE

#endif

#include <stdlib.h>

#include <stdio.h>

#include <string.h>

#include <unistd.h>

#include <errno.h>

#include <sched.h>

#ifndef __hermit__

#include <sys/syscall.h>

static inline long mygetpid(void)

{

return syscall(__NR_getpid);

}

#else

static inline long mygetpid(void)

{

return getpid();

}

int sched_yield(void);

#endif

#define N 10000

#define M (256+1)

#define BUFFSZ (1ULL*1024ULL*1024ULL)

static char* buff[M];

#if 1

inline static unsigned long long rdtsc(void)

{

unsigned long lo, hi;

asm volatile ("rdtsc" : "=a"(lo), "=d"(hi) :: "memory");

return ((unsigned long long) hi << 32ULL | (unsigned long long) lo);

}

#else

inline static unsigned long long rdtsc(void)

{

unsigned int lo, hi;

unsigned int id;

asm volatile ("rdtscp" : "=a"(lo), "=c"(id), "=d"(hi));

return ((unsigned long long)hi << 32ULL | (unsigned long long)lo);

}

#endif

int main(int argc, char** argv)

{

long i, j, ret;

unsigned long long start, end;

const char str[] = "H";

size_t len = strlen(str);

printf("Determine systems performance\n");

printf("=============================\n");

// cache warm-up

ret = mygetpid();

ret = mygetpid();

start = rdtsc();

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

ret = mygetpid();

end = rdtsc();

printf("Average time for getpid: %lld cycles, pid %ld\n", (end - start) / N, ret);

// cache warm-up

sched_yield();

sched_yield();

start = rdtsc();

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

sched_yield();

end = rdtsc();

printf("Average time for sched_yield: %lld cycles\n", (end - start) / N);

// cache warm-up

buff[0] = (char*) malloc(BUFFSZ);

start = rdtsc();

for(i=1; i<M; i++)

buff[i] = (char*) malloc(BUFFSZ);

end = rdtsc();

printf("Average time for malloc: %lld cycles\n", (end - start) / (M-1));

// cache warm-up

for(j=0; j<BUFFSZ; j+=4096)

buff[0][j] = '1';

start = rdtsc();

for(i=1; i<M; i++)

for(j=0; j<BUFFSZ; j+=4096)

buff[i][j] = '1';

end = rdtsc();

printf("Average time for the first page access: %lld cycles\n", (end - start) / ((M-1)*BUFFSZ/4096));

#if 0

write(2, (const void *)str, len);

write(2, (const void *)str, len);

start = rdtsc();

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

write(2, (const void *)str, len);

end = rdtsc();

printf("\nAverage time for write: %lld cycles\n", (end - start) / N);

#endif

return 0;

}