tools/tests/perf_index/test_fault_helper.c

   1 #include "test_fault_helper.h"
   2 #include "fail.h"
   3 #include <sys/mman.h>
   4 #include <stdlib.h>
   5 #include <unistd.h>
   6 #include <assert.h>
   7 #include <TargetConditionals.h>
   8
   9 #if (TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR)
  10 #define MEMSIZE (1L<<28)
  11 #else
  12 #define MEMSIZE (1L<<30)
  13 #endif
  14
  15 static char* memblock;
  16
  17 int
  18 test_fault_setup()
  19 {
  20         char *ptr;
  21         int pgsz = getpagesize();
  22         int retval;
  23
  24         memblock = (char *)mmap(NULL, MEMSIZE, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0);
  25         VERIFY(memblock != MAP_FAILED, "mmap failed");
  26
  27         /* make sure memory is paged */
  28         for (ptr = memblock; ptr < memblock + MEMSIZE; ptr += pgsz) {
  29                 *ptr = 1;
  30         }
  31
  32         /* set to read only, then back to read write so it faults on first write */
  33         retval = mprotect(memblock, MEMSIZE, PROT_READ);
  34         VERIFY(retval == 0, "mprotect failed");
  35
  36         retval = mprotect(memblock, MEMSIZE, PROT_READ | PROT_WRITE);
  37         VERIFY(retval == 0, "mprotect failed");
  38
  39         return PERFINDEX_SUCCESS;
  40 }
  41
  42 int
  43 test_fault_helper(int thread_id, int num_threads, long long length, testtype_t testtype)
  44 {
  45         char *ptr;
  46         int pgsz = getpagesize();
  47         int retval;
  48
  49         long long num_pages = MEMSIZE / pgsz;
  50         long long region_len = num_pages / num_threads;
  51         long long region_start = region_len * thread_id;
  52         long long region_end;
  53
  54         if (thread_id < num_pages % num_threads) {
  55                 region_start += thread_id;
  56                 region_len++;
  57         } else {
  58                 region_start += num_pages % num_threads;
  59         }
  60
  61         region_start *= pgsz;
  62         region_len *= pgsz;
  63         region_end = region_start + region_len;
  64
  65         long long left = length;
  66
  67         while (1) {
  68                 for (ptr = memblock + region_start; ptr < memblock + region_end; ptr += pgsz) {
  69                         *ptr = 1;
  70                         left--;
  71                         if (left == 0) {
  72                                 break;
  73                         }
  74                 }
  75
  76                 if (left == 0) {
  77                         break;
  78                 }
  79
  80                 if (testtype == TESTFAULT) {
  81                         retval = mprotect(memblock + region_start, region_len, PROT_READ) == 0;
  82                         VERIFY(retval == 0, "mprotect failed");
  83                         retval = mprotect(memblock + region_start, region_len, PROT_READ | PROT_WRITE) == 0;
  84                         VERIFY(retval == 0, "mprotect failed");
  85                 } else if (testtype == TESTZFOD) {
  86                         retval = munmap(memblock + region_start, region_len) == 0;
  87                         VERIFY(retval == 0, "munmap failed");
  88                         ptr = mmap(memblock + region_start, region_len, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE | MAP_FIXED, -1, 0);
  89                         VERIFY(ptr != 0, "mmap failed");
  90                 }
  91         }
  92         return PERFINDEX_SUCCESS;
  93 }