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