VirtualBox

source: vbox/trunk/src/VBox/Runtime/r3/linux/mp-linux.cpp@ 96407

Last change on this file since 96407 was 96407, checked in by vboxsync, 2 years ago

scm copyright and license note update
  • Property svn:eol-style set to native
  • Property svn:keywords set to Id Revision
File size: 9.5 KB
Line 
1/* $Id: mp-linux.cpp 96407 2022-08-22 17:43:14Z vboxsync $ */
2/** @file
3 * IPRT - Multiprocessor, Linux.
4 */
5
6/*
7 * Copyright (C) 2006-2022 Oracle and/or its affiliates.
8 *
9 * This file is part of VirtualBox base platform packages, as
10 * available from https://www.virtualbox.org.
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation, in version 3 of the
15 * License.
16 *
17 * This program is distributed in the hope that it will be useful, but
18 * WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20 * General Public License for more details.
21 *
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, see <https://www.gnu.org/licenses>.
24 *
25 * The contents of this file may alternatively be used under the terms
26 * of the Common Development and Distribution License Version 1.0
27 * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
28 * in the VirtualBox distribution, in which case the provisions of the
29 * CDDL are applicable instead of those of the GPL.
30 *
31 * You may elect to license modified versions of this file under the
32 * terms and conditions of either the GPL or the CDDL or both.
33 *
34 * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
35 */
36
37
38/*********************************************************************************************************************************
39* Header Files *
40*********************************************************************************************************************************/
41#define LOG_GROUP RTLOGGROUP_SYSTEM
42#include <stdio.h>
43#include <errno.h>
44
45#include <iprt/mp.h>
46#include "internal/iprt.h"
47
48#include <iprt/alloca.h>
49#include <iprt/cpuset.h>
50#include <iprt/assert.h>
51#include <iprt/string.h>
52#include <iprt/linux/sysfs.h>
53
54
55/**
56 * Internal worker that determines the max possible CPU count.
57 *
58 * @returns Max cpus.
59 */
60static RTCPUID rtMpLinuxMaxCpus(void)
61{
62#if 0 /* this doesn't do the right thing :-/ */
63 int cMax = sysconf(_SC_NPROCESSORS_CONF);
64 Assert(cMax >= 1);
65 return cMax;
66#else
67 static uint32_t s_cMax = 0;
68 if (!s_cMax)
69 {
70 int cMax = 1;
71 for (unsigned iCpu = 0; iCpu < RTCPUSET_MAX_CPUS; iCpu++)
72 if (RTLinuxSysFsExists("devices/system/cpu/cpu%d", iCpu))
73 cMax = iCpu + 1;
74 ASMAtomicUoWriteU32((uint32_t volatile *)&s_cMax, cMax);
75 return cMax;
76 }
77 return s_cMax;
78#endif
79}
80
81/**
82 * Internal worker that picks the processor speed in MHz from /proc/cpuinfo.
83 *
84 * @returns CPU frequency.
85 */
86static uint32_t rtMpLinuxGetFrequency(RTCPUID idCpu)
87{
88 FILE *pFile = fopen("/proc/cpuinfo", "r");
89 if (!pFile)
90 return 0;
91
92 char sz[256];
93 RTCPUID idCpuFound = NIL_RTCPUID;
94 uint32_t Frequency = 0;
95 while (fgets(sz, sizeof(sz), pFile))
96 {
97 char *psz;
98 if ( !strncmp(sz, RT_STR_TUPLE("processor"))
99 && (sz[10] == ' ' || sz[10] == '\t' || sz[10] == ':')
100 && (psz = strchr(sz, ':')))
101 {
102 psz += 2;
103 int64_t iCpu;
104 int rc = RTStrToInt64Ex(psz, NULL, 0, &iCpu);
105 if (RT_SUCCESS(rc))
106 idCpuFound = iCpu;
107 }
108 else if ( idCpu == idCpuFound
109 && !strncmp(sz, RT_STR_TUPLE("cpu MHz"))
110 && (sz[10] == ' ' || sz[10] == '\t' || sz[10] == ':')
111 && (psz = strchr(sz, ':')))
112 {
113 psz += 2;
114 int64_t v;
115 int rc = RTStrToInt64Ex(psz, &psz, 0, &v);
116 if (RT_SUCCESS(rc))
117 {
118 Frequency = v;
119 break;
120 }
121 }
122 }
123 fclose(pFile);
124 return Frequency;
125}
126
127
128/** @todo RTmpCpuId(). */
129
130RTDECL(int) RTMpCpuIdToSetIndex(RTCPUID idCpu)
131{
132 return idCpu < rtMpLinuxMaxCpus() ? (int)idCpu : -1;
133}
134
135
136RTDECL(RTCPUID) RTMpCpuIdFromSetIndex(int iCpu)
137{
138 return (unsigned)iCpu < rtMpLinuxMaxCpus() ? iCpu : NIL_RTCPUID;
139}
140
141
142RTDECL(RTCPUID) RTMpGetMaxCpuId(void)
143{
144 return rtMpLinuxMaxCpus() - 1;
145}
146
147
148RTDECL(bool) RTMpIsCpuOnline(RTCPUID idCpu)
149{
150 /** @todo check if there is a simpler interface than this... */
151 int64_t i = 0;
152 int rc = RTLinuxSysFsReadIntFile(0, &i, "devices/system/cpu/cpu%d/online", (int)idCpu);
153 if ( RT_FAILURE(rc)
154 && RTLinuxSysFsExists("devices/system/cpu/cpu%d", (int)idCpu))
155 {
156 /** @todo Assert(!RTLinuxSysFsExists("devices/system/cpu/cpu%d/online",
157 * (int)idCpu));
158 * Unfortunately, the online file wasn't always world readable (centos
159 * 2.6.18-164). */
160 i = 1;
161 rc = VINF_SUCCESS;
162 }
163
164 AssertMsg(i == 0 || i == -1 || i == 1, ("i=%d\n", i));
165 return RT_SUCCESS(rc) && i != 0;
166}
167
168
169RTDECL(bool) RTMpIsCpuPossible(RTCPUID idCpu)
170{
171 /** @todo check this up with hotplugging! */
172 return RTLinuxSysFsExists("devices/system/cpu/cpu%d", (int)idCpu);
173}
174
175
176RTDECL(PRTCPUSET) RTMpGetSet(PRTCPUSET pSet)
177{
178 RTCpuSetEmpty(pSet);
179 RTCPUID cMax = rtMpLinuxMaxCpus();
180 for (RTCPUID idCpu = 0; idCpu < cMax; idCpu++)
181 if (RTMpIsCpuPossible(idCpu))
182 RTCpuSetAdd(pSet, idCpu);
183 return pSet;
184}
185
186
187RTDECL(RTCPUID) RTMpGetCount(void)
188{
189 RTCPUSET Set;
190 RTMpGetSet(&Set);
191 return RTCpuSetCount(&Set);
192}
193
194
195RTDECL(RTCPUID) RTMpGetCoreCount(void)
196{
197 RTCPUID cMax = rtMpLinuxMaxCpus();
198 uint32_t *paidCores = (uint32_t *)alloca(sizeof(paidCores[0]) * (cMax + 1));
199 uint32_t *paidPckgs = (uint32_t *)alloca(sizeof(paidPckgs[0]) * (cMax + 1));
200 uint32_t cCores = 0;
201 for (RTCPUID idCpu = 0; idCpu < cMax; idCpu++)
202 {
203 if (RTMpIsCpuPossible(idCpu))
204 {
205 int64_t idCore = 0;
206 int64_t idPckg = 0;
207
208 int rc = RTLinuxSysFsReadIntFile(0, &idCore, "devices/system/cpu/cpu%d/topology/core_id", (int)idCpu);
209 if (RT_SUCCESS(rc))
210 rc = RTLinuxSysFsReadIntFile(0, &idPckg, "devices/system/cpu/cpu%d/topology/physical_package_id", (int)idCpu);
211
212 if (RT_SUCCESS(rc))
213 {
214 uint32_t i;
215
216 for (i = 0; i < cCores; i++)
217 if ( paidCores[i] == (uint32_t)idCore
218 && paidPckgs[i] == (uint32_t)idPckg)
219 break;
220 if (i >= cCores)
221 {
222 paidCores[cCores] = (uint32_t)idCore;
223 paidPckgs[cCores] = (uint32_t)idPckg;
224 cCores++;
225 }
226 }
227 }
228 }
229 Assert(cCores > 0);
230 return cCores;
231}
232
233
234RTDECL(PRTCPUSET) RTMpGetOnlineSet(PRTCPUSET pSet)
235{
236 RTCpuSetEmpty(pSet);
237 RTCPUID cMax = rtMpLinuxMaxCpus();
238 for (RTCPUID idCpu = 0; idCpu < cMax; idCpu++)
239 if (RTMpIsCpuOnline(idCpu))
240 RTCpuSetAdd(pSet, idCpu);
241 return pSet;
242}
243
244
245RTDECL(RTCPUID) RTMpGetOnlineCount(void)
246{
247 RTCPUSET Set;
248 RTMpGetOnlineSet(&Set);
249 return RTCpuSetCount(&Set);
250}
251
252
253RTDECL(RTCPUID) RTMpGetOnlineCoreCount(void)
254{
255 RTCPUID cMax = rtMpLinuxMaxCpus();
256 uint32_t *paidCores = (uint32_t *)alloca(sizeof(paidCores[0]) * (cMax + 1));
257 uint32_t *paidPckgs = (uint32_t *)alloca(sizeof(paidPckgs[0]) * (cMax + 1));
258 uint32_t cCores = 0;
259 for (RTCPUID idCpu = 0; idCpu < cMax; idCpu++)
260 {
261 if (RTMpIsCpuOnline(idCpu))
262 {
263 int64_t idCore = 0;
264 int64_t idPckg = 0;
265
266 int rc = RTLinuxSysFsReadIntFile(0, &idCore, "devices/system/cpu/cpu%d/topology/core_id", (int)idCpu);
267 if (RT_SUCCESS(rc))
268 rc = RTLinuxSysFsReadIntFile(0, &idPckg, "devices/system/cpu/cpu%d/topology/physical_package_id", (int)idCpu);
269
270 if (RT_SUCCESS(rc))
271 {
272 uint32_t i;
273
274 for (i = 0; i < cCores; i++)
275 if ( paidCores[i] == idCore
276 && paidPckgs[i] == idPckg)
277 break;
278 if (i >= cCores)
279 {
280 paidCores[cCores] = idCore;
281 paidPckgs[cCores] = idPckg;
282 cCores++;
283 }
284 }
285 }
286 }
287 Assert(cCores > 0);
288 return cCores;
289}
290
291
292
293RTDECL(uint32_t) RTMpGetCurFrequency(RTCPUID idCpu)
294{
295 int64_t kHz = 0;
296 int rc = RTLinuxSysFsReadIntFile(0, &kHz, "devices/system/cpu/cpu%d/cpufreq/cpuinfo_cur_freq", (int)idCpu);
297 if (RT_FAILURE(rc))
298 {
299 /*
300 * The file may be just unreadable - in that case use plan B, i.e.
301 * /proc/cpuinfo to get the data we want. The assumption is that if
302 * cpuinfo_cur_freq doesn't exist then the speed won't change, and
303 * thus cur == max. If it does exist then cpuinfo contains the
304 * current frequency.
305 */
306 kHz = rtMpLinuxGetFrequency(idCpu) * 1000;
307 }
308 return (kHz + 999) / 1000;
309}
310
311
312RTDECL(uint32_t) RTMpGetMaxFrequency(RTCPUID idCpu)
313{
314 int64_t kHz = 0;
315 int rc = RTLinuxSysFsReadIntFile(0, &kHz, "devices/system/cpu/cpu%d/cpufreq/cpuinfo_max_freq", (int)idCpu);
316 if (RT_FAILURE(rc))
317 {
318 /*
319 * Check if the file isn't there - if it is there, then /proc/cpuinfo
320 * would provide current frequency information, which is wrong.
321 */
322 if (!RTLinuxSysFsExists("devices/system/cpu/cpu%d/cpufreq/cpuinfo_max_freq", (int)idCpu))
323 kHz = rtMpLinuxGetFrequency(idCpu) * 1000;
324 else
325 kHz = 0;
326 }
327 return (kHz + 999) / 1000;
328}
Note: See TracBrowser for help on using the repository browser.

© 2024 Oracle Support Privacy / Do Not Sell My Info Terms of Use Trademark Policy Automated Access Etiquette