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#ifndef __CACHE_COMMON_H__
#define __CACHE_COMMON_H__
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>
#include <assert.h>
#include <signal.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/io.h>
#include <sys/utsname.h>
#include <sched.h>
#include <sys/time.h>
#include <sys/resource.h>
#include "litmus.h"
#include "asm/cycles.h"
#if defined(__i386__) || defined(__x86_64__)
#include "asm/irq.h"
#endif
#define UNCACHE_DEV "/dev/litmus/uncache"
static void die(char *error)
{
fprintf(stderr, "Error: %s (errno: %m)\n",
error);
exit(1);
}
static int lock_memory(void)
{
return mlockall(MCL_CURRENT | MCL_FUTURE);
}
/* define CACHELINE_SIZE if not provided by compiler args */
#ifndef CACHELINE_SIZE
#if defined(__i386__) || defined(__x86_64__)
/* recent intel cpus */
#define CACHELINE_SIZE 64
#elif defined(__arm__)
/* at least with Cortex-A9 cpus ("8 words") */
#define CACHELINE_SIZE 32
#else
#error "Could not determine cacheline size!"
#endif
#endif
#define INTS_IN_CACHELINE (CACHELINE_SIZE/sizeof(int))
typedef struct cacheline
{
int line[INTS_IN_CACHELINE];
} __attribute__((aligned(CACHELINE_SIZE))) cacheline_t;
#define CACHELINES_IN_1KB (1024 / sizeof(cacheline_t))
static cacheline_t* alloc_arena(size_t size, int use_huge_pages, int use_uncache_pages)
{
int flags = MAP_PRIVATE | MAP_POPULATE;
cacheline_t* arena = NULL;
int fd;
if(use_huge_pages)
flags |= MAP_HUGETLB;
if(use_uncache_pages) {
fd = open(UNCACHE_DEV, O_RDWR);
if (fd == -1)
die("Failed to open uncache device. Are you running the LITMUS^RT kernel?");
}
else {
fd = -1;
flags |= MAP_ANONYMOUS;
}
arena = mmap(0, size, PROT_READ | PROT_WRITE, flags, fd, 0);
if(use_uncache_pages)
close(fd);
assert(arena);
return arena;
}
static void dealloc_arena(cacheline_t* arena, size_t size)
{
int ret = munmap((void*)arena, size);
if(ret != 0)
die("munmap() error");
}
static int randrange(int min, int max)
{
/* generate a random number on the range [min, max) w/o skew */
int limit = max - min;
int devisor = RAND_MAX/limit;
int retval;
do {
retval = rand() / devisor;
} while(retval == limit);
retval += min;
return retval;
}
static void init_arena(cacheline_t* arena, size_t size)
{
int i;
size_t num_arena_elem = size / sizeof(cacheline_t);
/* Generate a cycle among the cache lines using Sattolo's algorithm.
Every int in the cache line points to the same cache line.
Note: Sequential walk doesn't care about these values. */
for (i = 0; i < num_arena_elem; i++) {
int j;
for(j = 0; j < INTS_IN_CACHELINE; ++j)
arena[i].line[j] = i;
}
while(1 < i--) {
int j = randrange(0, i);
cacheline_t temp = arena[j];
arena[j] = arena[i];
arena[i] = temp;
}
}
#endif
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