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 hw_memsize(void)
13 {
14 int mib[2];
15 size_t len;
16 size_t my_memsize;
17 int retval;
18
19 mib[0] = CTL_HW;
20 mib[1] = HW_MEMSIZE;
21 len = sizeof(my_memsize);
22
23 retval = sysctl(mib, 2, &my_memsize, &len, NULL, 0);
24
25 if (retval != 0) {
26 return 0;
27 }
28
29 return my_memsize;
30 }
31
32 DECL_SETUP {
33 char *memblockfiller;
34 long long i;
35 int pgsz = getpagesize();
36
37 /* Heuristic: use half the physical memory, hopefully this should work on all
38 * devices. We use the amount of physical memory, rather than some softer
39 * metric, like amount of free memory, so that the memory allocated is always
40 * consistent for a given device.
41 */
42 memsize = hw_memsize();
43 VERIFY(memsize > 0, "hw_memsize failed");
44 memsize = memsize / 2;
45
46 memblock = (char*)malloc(memsize);
47 VERIFY(memblock != NULL, "malloc failed");
48
49 memblockfiller = memblock;
50
51 /* Do this manually, to make sure everything is paged in */
52 for (i = 0; i < memsize; i += pgsz) {
53 memblockfiller[i] = 1;
54 }
55
56 return PERFINDEX_SUCCESS;
57 }
58
59 /* figures out what region of memory to copy, so it does interfere with other
60 * threads, */
61 DECL_TEST {
62 long long left = length;
63 long long region_len = memsize / num_threads / 2;
64 long long region_start = memsize / num_threads * thread_id / 2;
65 long long copy_len;
66
67 if (thread_id < memsize / 2 % num_threads) {
68 region_start += thread_id;
69 region_len++;
70 } else {
71 region_start += memsize / 2 % num_threads;
72 }
73
74 while (left > 0) {
75 copy_len = region_len < left ? region_len : left;
76 memcpy(memblock + region_start + memsize / 2, memblock + region_start, copy_len);
77 left -= copy_len;
78 }
79
80 return PERFINDEX_SUCCESS;
81 }
82
83 DECL_CLEANUP {
84 free(memblock);
85 return PERFINDEX_SUCCESS;
86 }
87