tools/tests/perf_index/perfindex-memory.c

   1 #include "perf_index.h"
   2 #include "fail.h"
   3 #include <stdlib.h>
   4 #include <unistd.h>
   5 #include <string.h>
   6 #include <sys/sysctl.h>
   7
   8 static char *memblock;
   9 static size_t memsize;
  10
  11 size_t hw_memsize(void) {
  12   int mib[2];
  13   size_t len;
  14   size_t my_memsize;
  15   int retval;
  16
  17   mib[0] = CTL_HW;
  18   mib[1] = HW_MEMSIZE;
  19   len = sizeof(my_memsize);
  20
  21   retval = sysctl(mib, 2, &my_memsize, &len, NULL, 0);
  22
  23   if(retval != 0)
  24       return 0;
  25
  26   return my_memsize;
  27 }
  28
  29 DECL_SETUP {
  30   char *memblockfiller;
  31   long long i;
  32   int pgsz = getpagesize();
  33
  34   /* Heuristic: use half the physical memory, hopefully this should work on all
  35    * devices. We use the amount of physical memory, rather than some softer
  36    * metric, like amount of free memory, so that the memory allocated is always
  37    * consistent for a given device.
  38    */
  39   memsize = hw_memsize();
  40   VERIFY(memsize > 0, "hw_memsize failed");
  41   memsize = memsize/2;
  42
  43   memblock = (char*)malloc(memsize);
  44   VERIFY(memblock != NULL, "malloc failed");
  45
  46   memblockfiller = memblock;
  47
  48   /* Do this manually, to make sure everything is paged in */
  49   for(i=0; i<memsize; i+=pgsz) {
  50     memblockfiller[i] = 1;
  51   }
  52
  53   return PERFINDEX_SUCCESS;
  54 }
  55
  56 /* figures out what region of memory to copy, so it does interfere with other
  57 threads,  */
  58 DECL_TEST {
  59   long long left = length;
  60   long long region_len = memsize / num_threads / 2;
  61   long long region_start = memsize / num_threads * thread_id / 2;
  62   long long copy_len;
  63
  64   if(thread_id < memsize / 2 % num_threads) {
  65     region_start += thread_id;
  66     region_len++;
  67   }
  68   else {
  69     region_start += memsize / 2 % num_threads;
  70   }
  71
  72   while(left>0) {
  73     copy_len = region_len < left ? region_len : left;
  74     memcpy(memblock+region_start+memsize/2, memblock+region_start, copy_len);
  75     left -= copy_len;
  76   }
  77
  78   return PERFINDEX_SUCCESS;
  79 }
  80
  81 DECL_CLEANUP {
  82     free(memblock);
  83     return PERFINDEX_SUCCESS;
  84 }