The FreeRADIUS server  $Id: 15bac2a4c627c01d1aa2047687b3418955ac7f00 $
hw.c
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1 /*
2  * This program is is free software; you can redistribute it and/or modify
3  * it under the terms of the GNU General Public License, version 2 of the
4  * License as published by the Free Software Foundation.
5  *
6  * This program is distributed in the hope that it will be useful,
7  * but WITHOUT ANY WARRANTY; without even the implied warranty of
8  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
9  * GNU General Public License for more details.
10  *
11  * You should have received a copy of the GNU General Public License
12  * along with this program; if not, write to the Free Software
13  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
14  */
15 
16 /** Functions for getting information about the system architecture
17  *
18  * @file src/lib/util/hw.c
19  *
20  * @author Arran Cudbard-Bell (a.cudbardb@freeradius.org)
21  * @copyright 2020 Arran Cudbard-Bell (a.cudbardb@freeradius.org)
22  */
23 
24 #define CACHE_LINE_DEFAULT 128
25 #define CORES_DEFAULT 1
26 
27 #include <freeradius-devel/util/hw.h>
28 #include <freeradius-devel/util/syserror.h>
29 #include <freeradius-devel/util/strerror.h>
30 #include <errno.h>
31 
32 #if defined(__APPLE__) || defined(__FreeBSD__)
33 #include <sys/sysctl.h>
34 size_t fr_hw_cache_line_size(void)
35 {
36  size_t cache_line_size = CACHE_LINE_DEFAULT;
37  size_t cache_line_size_len = sizeof(cache_line_size);
38 
39  sysctlbyname("hw.cachelinesize", &cache_line_size, &cache_line_size_len, 0, 0);
40 
41  return cache_line_size;
42 }
43 
45 {
46  uint32_t num_cores = CORES_DEFAULT;
47  size_t num_cores_len = sizeof(num_cores);
48 
49  sysctlbyname("hw.physicalcpu", &num_cores, &num_cores_len, 0, 0);
50 
51  return num_cores;
52 }
53 
54 #elif defined(__linux__)
55 #include <stdio.h>
56 #include <unistd.h>
57 size_t fr_hw_cache_line_size(void)
58 {
59  FILE *file = NULL;
60  unsigned int cache_line_size = CACHE_LINE_DEFAULT;
61 
62  file = fopen("/sys/devices/system/cpu/cpu0/cache/index0/coherency_cache_line_size", "r");
63  if (file) {
64  if (fscanf(file, "%d", &cache_line_size) != 1) {
65  cache_line_size = CACHE_LINE_DEFAULT;
66  }
67  fclose(file);
68  }
69 
70  return cache_line_size;
71 }
72 
74 {
75  uint32_t lcores = 0, tsibs = 0;
76 
77  char buff[32];
78  char path[64];
79 
80  for (lcores = 0;;lcores++) {
81  FILE *cpu;
82 
83  snprintf(path, sizeof(path), "/sys/devices/system/cpu/cpu%u/topology/thread_siblings_list", lcores);
84 
85  cpu = fopen(path, "r");
86  if (!cpu) break;
87 
88  while (fscanf(cpu, "%[0-9]", buff)) {
89  tsibs++;
90  if (fgetc(cpu) != ',') break;
91  }
92 
93  fclose(cpu);
94  }
95 
96  /*
97  * Catch Linux weirdness.
98  *
99  * You'd think this would be enough to quiet clang scan,
100  * but it's not.
101  */
102  if (unlikely((tsibs == 0) || (lcores == 0) || (lcores > tsibs))) {
103  fr_strerror_printf("Failed retrieving cpu topology info: %s", fr_syserror(errno));
104  return 0;
105  }
106 
107 #ifdef STATIC_ANALYZER
108  /*
109  * Prevent static analyzer from warning about divide by zero
110  */
111  if ((tsibs / lcores) == 0) return 0;
112 #endif
113 
114  return lcores / (tsibs / lcores);
115 }
116 #else
118 {
119  return CACHE_LINE_DEFAULT;
120 }
121 
123 {
124  return CORES_DEFAULT;
125 }
126 #endif
int const char * file
Definition: acutest.h:702
#define unlikely(_x)
Definition: build.h:379
size_t fr_hw_cache_line_size(void)
Definition: hw.c:117
#define CACHE_LINE_DEFAULT
Definition: hw.c:24
#define CORES_DEFAULT
Definition: hw.c:25
uint32_t fr_hw_num_cores_active(void)
Definition: hw.c:122
unsigned int uint32_t
Definition: merged_model.c:33
static char buff[sizeof("18446744073709551615")+3]
Definition: size_tests.c:41
PUBLIC int snprintf(char *string, size_t length, char *format, va_alist)
Definition: snprintf.c:689
char const * fr_syserror(int num)
Guaranteed to be thread-safe version of strerror.
Definition: syserror.c:243
#define fr_strerror_printf(_fmt,...)
Log to thread local error buffer.
Definition: strerror.h:64