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#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <inttypes.h>
#include "asm/cacheparams.h"
#include <litmus/rt_param.h>
#include "perfcounters.h"
#include "color.h"
#include "litmus.h"
#define CPU 1
#define NR_LOOPS 10000
static int pages_per_datum;
/* Number of pages in a "data" element, each with same color. */
static int nr_data;
/* Number of "data" elements. */
struct page;
#define NR_PAGE_INTS ((PAGE_SIZE - CACHE_LINE_SIZE) / sizeof(uint32_t))
struct page {
struct page *ptr;
struct page *_unused[CACHE_LINE_SIZE / sizeof(struct page*) - 1];
uint32_t ints[NR_PAGE_INTS];
};
struct datum {
struct page *pages;
};
/*
* Get a random number in [0, max). Not really a good way to do this.
*/
static int randrange(const int max)
{
return (rand() / (RAND_MAX / max + 1));
}
static void setup_page_ints(struct page *page)
{
int i;
for (i = 0; i < NR_PAGE_INTS; i++) {
page->ints[i] = randrange(RAND_MAX);
}
}
/*
* Sattolo's algorithm makes a random cycle that includes all the elements
* in the items array.
*/
static void sattolo(int *items, const int len)
{
int i;
/* first set up 0, 1, ..., n - 1 */
for (i = 0; i < len; i++)
items[i] = i;
/* note: i is now n */
while (1 < i--) {
/* 0 <= j < i */
int t, j = randrange(i);
t = items[i];
items[i] = items[j];
items[j] = t;
}
}
static uint32_t get_sum(struct page *page)
{
uint32_t sum = 0;
int i;
for (i = 0; i < NR_PAGE_INTS; i += CACHE_LINE_SIZE / sizeof(uint32_t)) {
sum += page->ints[i];
}
return sum;
}
static uint32_t do_read(struct page* page)
{
struct page *old;
uint32_t sum = 0;
do {
old = page;
page = page->ptr;
sum += get_sum(old);
} while (page);
return sum;
}
#define MULT 699050667
#define SHIFT 24
static inline int64_t clocksource_cyc2ns(cycles_t cycles, uint32_t mult, uint32_t shift)
{
return ((uint64_t) cycles * mult) >> shift;
}
#if 0
static void print_difference(const cycles_t start, const cycles_t end)
{
cycles_t diff = end - start;
printf("difference: %10llu = %10llu ns\n", diff, clocksource_cyc2ns(diff, MULT, SHIFT));
}
#endif
#define quit_on_err(err, msg) do { \
if (err) { \
fprintf(stderr, "error: " msg); \
goto out; \
} \
} while (0)
int main(int argc, char **argv)
{
struct color_ctrl_page *color_ctrl;
struct datum *data;
int *read_order;
int i, j, err = 0;
cycles_t start, end;
uint32_t sum = 0;
int64_t nanoseconds;
double avg_nanoseconds;
quit_on_err(PAGE_SIZE != sizeof(struct page),
"PAGE_SIZE != sizeof(struct page)\n");
if (3 > argc) {
fprintf(stderr, "%s: [pages-per-datum] [nr-data]\n", argv[0]);
err = 1;
goto out;
}
pages_per_datum = atoi(argv[1]);
nr_data = atoi(argv[2]);
quit_on_err(0 == nr_data || 0 == pages_per_datum, "zero argument\n");
quit_on_err(16 < nr_data, "too many nr_data\n");
read_order = malloc(pages_per_datum * sizeof(*read_order));
data = malloc(nr_data * sizeof(*data));
quit_on_err(!read_order || !data, "malloc\n");
err = be_migrate_to(CPU);
quit_on_err(err, "migrate to cpu\n");
color_ctrl = get_color_ctrl();
if (!color_ctrl) {
fprintf(stderr, "could not map color ctrl\n");
err = -1;
goto out;
}
/* Always allocating this many pages of the same color. */
color_ctrl->pages[0] = pages_per_datum;
for (i = 0; i < nr_data; i++) {
const unsigned nr_bytes = sizeof(data[i].pages[0]) * pages_per_datum;
/* give each datum its own color (XXX no checks to ensure not >
* NR_COLORS!) */
color_ctrl->colors[0] = i;
fprintf(stderr, "color_mallocing %u bytes\n", nr_bytes);
data[i].pages = color_malloc(nr_bytes);
if (!data[i].pages) {
fprintf(stderr, "could not color malloc\n");
err = -1;
goto out;
}
}
sattolo(read_order, pages_per_datum);
for (i = 0; i < nr_data; i++) {
for (j = 0; j < pages_per_datum; j++) {
if (0 != read_order[j]) {
/* not the last element */
data[i].pages[j].ptr = &(data[i].pages[read_order[j]]);
} else {
/* last element in pages inside of datum walk */
if (nr_data - 1 == i) {
/* last element globally */
data[i].pages[j].ptr = NULL;
} else {
/* jump to next datum */
data[i].pages[j].ptr = &(data[i + 1].pages[0]);
}
}
setup_page_ints(&(data[i].pages[j]));
}
}
#if 0
null_call(&start);
null_call(&end);
print_difference(start, end);
null_call(&start);
sum += do_read(data[0].pages);
null_call(&end);
print_difference(start, end);
null_call(&start);
sum += do_read(data[0].pages);
null_call(&end);
print_difference(start, end);
null_call(&start);
sum += do_read(data[0].pages);
null_call(&end);
print_difference(start, end);
#endif
null_call(&start);
for (i = 0; i < NR_LOOPS; i++) {
sum += do_read(data[0].pages);
}
null_call(&end);
nanoseconds = clocksource_cyc2ns(end - start, MULT, SHIFT);
avg_nanoseconds = ((double)nanoseconds) / NR_LOOPS;
printf("%3d, %10.3f, %10.3f\n", nr_data, avg_nanoseconds,
avg_nanoseconds / (nr_data * pages_per_datum));
out:
return err;
}
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