VirtualBox

source: vbox/trunk/src/VBox/Runtime/r3/linux/mp-linux.cpp@ 50059

Last change on this file since 50059 was 50059, checked in by vboxsync, 11 years ago

Runtime/r3/linux: when determining the number of physical cores, also consider the physical package ID of each core
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  • Property svn:keywords set to Id Revision
File size: 8.5 KB
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1/* $Id: mp-linux.cpp 50059 2014-01-13 09:10:18Z vboxsync $ */
2/** @file
3 * IPRT - Multiprocessor, Linux.
4 */
5
6/*
7 * Copyright (C) 2006-2010 Oracle Corporation
8 *
9 * This file is part of VirtualBox Open Source Edition (OSE), as
10 * available from http://www.virtualbox.org. This file is free software;
11 * you can redistribute it and/or modify it under the terms of the GNU
12 * General Public License (GPL) as published by the Free Software
13 * Foundation, in version 2 as it comes in the "COPYING" file of the
14 * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
15 * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
16 *
17 * The contents of this file may alternatively be used under the terms
18 * of the Common Development and Distribution License Version 1.0
19 * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
20 * VirtualBox OSE distribution, in which case the provisions of the
21 * CDDL are applicable instead of those of the GPL.
22 *
23 * You may elect to license modified versions of this file under the
24 * terms and conditions of either the GPL or the CDDL or both.
25 */
26
27
28/*******************************************************************************
29* Header Files *
30*******************************************************************************/
31#define LOG_GROUP RTLOGGROUP_SYSTEM
32#include <stdio.h>
33#include <errno.h>
34
35#include <iprt/mp.h>
36#include "internal/iprt.h"
37
38#include <iprt/alloca.h>
39#include <iprt/cpuset.h>
40#include <iprt/assert.h>
41#include <iprt/string.h>
42#include <iprt/linux/sysfs.h>
43
44
45/**
46 * Internal worker that determines the max possible CPU count.
47 *
48 * @returns Max cpus.
49 */
50static RTCPUID rtMpLinuxMaxCpus(void)
51{
52#if 0 /* this doesn't do the right thing :-/ */
53 int cMax = sysconf(_SC_NPROCESSORS_CONF);
54 Assert(cMax >= 1);
55 return cMax;
56#else
57 static uint32_t s_cMax = 0;
58 if (!s_cMax)
59 {
60 int cMax = 1;
61 for (unsigned iCpu = 0; iCpu < RTCPUSET_MAX_CPUS; iCpu++)
62 if (RTLinuxSysFsExists("devices/system/cpu/cpu%d", iCpu))
63 cMax = iCpu + 1;
64 ASMAtomicUoWriteU32((uint32_t volatile *)&s_cMax, cMax);
65 return cMax;
66 }
67 return s_cMax;
68#endif
69}
70
71/**
72 * Internal worker that picks the processor speed in MHz from /proc/cpuinfo.
73 *
74 * @returns CPU frequency.
75 */
76static uint32_t rtMpLinuxGetFrequency(RTCPUID idCpu)
77{
78 FILE *pFile = fopen("/proc/cpuinfo", "r");
79 if (!pFile)
80 return 0;
81
82 char sz[256];
83 RTCPUID idCpuFound = NIL_RTCPUID;
84 uint32_t Frequency = 0;
85 while (fgets(sz, sizeof(sz), pFile))
86 {
87 char *psz;
88 if ( !strncmp(sz, RT_STR_TUPLE("processor"))
89 && (sz[10] == ' ' || sz[10] == '\t' || sz[10] == ':')
90 && (psz = strchr(sz, ':')))
91 {
92 psz += 2;
93 int64_t iCpu;
94 int rc = RTStrToInt64Ex(psz, NULL, 0, &iCpu);
95 if (RT_SUCCESS(rc))
96 idCpuFound = iCpu;
97 }
98 else if ( idCpu == idCpuFound
99 && !strncmp(sz, RT_STR_TUPLE("cpu MHz"))
100 && (sz[10] == ' ' || sz[10] == '\t' || sz[10] == ':')
101 && (psz = strchr(sz, ':')))
102 {
103 psz += 2;
104 int64_t v;
105 int rc = RTStrToInt64Ex(psz, &psz, 0, &v);
106 if (RT_SUCCESS(rc))
107 {
108 Frequency = v;
109 break;
110 }
111 }
112 }
113 fclose(pFile);
114 return Frequency;
115}
116
117
118/** @todo RTmpCpuId(). */
119
120RTDECL(int) RTMpCpuIdToSetIndex(RTCPUID idCpu)
121{
122 return idCpu < rtMpLinuxMaxCpus() ? (int)idCpu : -1;
123}
124
125
126RTDECL(RTCPUID) RTMpCpuIdFromSetIndex(int iCpu)
127{
128 return (unsigned)iCpu < rtMpLinuxMaxCpus() ? iCpu : NIL_RTCPUID;
129}
130
131
132RTDECL(RTCPUID) RTMpGetMaxCpuId(void)
133{
134 return rtMpLinuxMaxCpus() - 1;
135}
136
137
138RTDECL(bool) RTMpIsCpuOnline(RTCPUID idCpu)
139{
140 /** @todo check if there is a simpler interface than this... */
141 int i = RTLinuxSysFsReadIntFile(0, "devices/system/cpu/cpu%d/online", (int)idCpu);
142 if ( i == -1
143 && RTLinuxSysFsExists("devices/system/cpu/cpu%d", (int)idCpu))
144 {
145 /** @todo Assert(!RTLinuxSysFsExists("devices/system/cpu/cpu%d/online",
146 * (int)idCpu));
147 * Unfortunately, the online file wasn't always world readable (centos
148 * 2.6.18-164). */
149 i = 1;
150 }
151
152 AssertMsg(i == 0 || i == -1 || i == 1, ("i=%d\n", i));
153 return i != 0 && i != -1;
154}
155
156
157RTDECL(bool) RTMpIsCpuPossible(RTCPUID idCpu)
158{
159 /** @todo check this up with hotplugging! */
160 return RTLinuxSysFsExists("devices/system/cpu/cpu%d", (int)idCpu);
161}
162
163
164RTDECL(PRTCPUSET) RTMpGetSet(PRTCPUSET pSet)
165{
166 RTCpuSetEmpty(pSet);
167 RTCPUID cMax = rtMpLinuxMaxCpus();
168 for (RTCPUID idCpu = 0; idCpu < cMax; idCpu++)
169 if (RTMpIsCpuPossible(idCpu))
170 RTCpuSetAdd(pSet, idCpu);
171 return pSet;
172}
173
174
175RTDECL(RTCPUID) RTMpGetCount(void)
176{
177 RTCPUSET Set;
178 RTMpGetSet(&Set);
179 return RTCpuSetCount(&Set);
180}
181
182
183RTDECL(RTCPUID) RTMpGetCoreCount(void)
184{
185 RTCPUID cMax = rtMpLinuxMaxCpus();
186 uint32_t *paidCores = (uint32_t *)alloca(sizeof(paidCores[0]) * (cMax + 1));
187 uint32_t *paidPckgs = (uint32_t *)alloca(sizeof(paidPckgs[0]) * (cMax + 1));
188 uint32_t cCores = 0;
189 for (RTCPUID idCpu = 0; idCpu < cMax; idCpu++)
190 {
191 if (RTMpIsCpuPossible(idCpu))
192 {
193 uint32_t idCore = (uint32_t)RTLinuxSysFsReadIntFile(0, "devices/system/cpu/cpu%d/topology/core_id", (int)idCpu);
194 uint32_t idPckg = (uint32_t)RTLinuxSysFsReadIntFile(0, "devices/system/cpu/cpu%d/topology/physical_package_id", (int)idCpu);
195 uint32_t i;
196 for (i = 0; i < cCores; i++)
197 if ( paidCores[i] == idCore
198 && paidPckgs[i] == idPckg)
199 break;
200 if (i >= cCores)
201 {
202 paidCores[cCores] = idCore;
203 paidPckgs[cCores] = idPckg;
204 cCores++;
205 }
206 }
207 }
208 Assert(cCores > 0);
209 return cCores;
210}
211
212
213RTDECL(PRTCPUSET) RTMpGetOnlineSet(PRTCPUSET pSet)
214{
215 RTCpuSetEmpty(pSet);
216 RTCPUID cMax = rtMpLinuxMaxCpus();
217 for (RTCPUID idCpu = 0; idCpu < cMax; idCpu++)
218 if (RTMpIsCpuOnline(idCpu))
219 RTCpuSetAdd(pSet, idCpu);
220 return pSet;
221}
222
223
224RTDECL(RTCPUID) RTMpGetOnlineCount(void)
225{
226 RTCPUSET Set;
227 RTMpGetOnlineSet(&Set);
228 return RTCpuSetCount(&Set);
229}
230
231
232RTDECL(RTCPUID) RTMpGetOnlineCoreCount(void)
233{
234 RTCPUID cMax = rtMpLinuxMaxCpus();
235 uint32_t *paidCores = (uint32_t *)alloca(sizeof(paidCores[0]) * (cMax + 1));
236 uint32_t *paidPckgs = (uint32_t *)alloca(sizeof(paidPckgs[0]) * (cMax + 1));
237 uint32_t cCores = 0;
238 for (RTCPUID idCpu = 0; idCpu < cMax; idCpu++)
239 {
240 if (RTMpIsCpuOnline(idCpu))
241 {
242 uint32_t idCore = (uint32_t)RTLinuxSysFsReadIntFile(0, "devices/system/cpu/cpu%d/topology/core_id", (int)idCpu);
243 uint32_t idPckg = (uint32_t)RTLinuxSysFsReadIntFile(0, "devices/system/cpu/cpu%d/topology/physical_package_id", (int)idCpu);
244 uint32_t i;
245 for (i = 0; i < cCores; i++)
246 if ( paidCores[i] == idCore
247 && paidPckgs[i] == idPckg)
248 break;
249 if (i >= cCores)
250 {
251 paidCores[cCores] = idCore;
252 paidPckgs[cCores] = idPckg;
253 cCores++;
254 }
255 }
256 }
257 Assert(cCores > 0);
258 return cCores;
259}
260
261
262
263RTDECL(uint32_t) RTMpGetCurFrequency(RTCPUID idCpu)
264{
265 int64_t kHz = RTLinuxSysFsReadIntFile(0, "devices/system/cpu/cpu%d/cpufreq/cpuinfo_cur_freq", (int)idCpu);
266 if (kHz == -1)
267 {
268 /*
269 * The file may be just unreadable - in that case use plan B, i.e.
270 * /proc/cpuinfo to get the data we want. The assumption is that if
271 * cpuinfo_cur_freq doesn't exist then the speed won't change, and
272 * thus cur == max. If it does exist then cpuinfo contains the
273 * current frequency.
274 */
275 kHz = rtMpLinuxGetFrequency(idCpu) * 1000;
276 }
277 return (kHz + 999) / 1000;
278}
279
280
281RTDECL(uint32_t) RTMpGetMaxFrequency(RTCPUID idCpu)
282{
283 int64_t kHz = RTLinuxSysFsReadIntFile(0, "devices/system/cpu/cpu%d/cpufreq/cpuinfo_max_freq", (int)idCpu);
284 if (kHz == -1)
285 {
286 /*
287 * Check if the file isn't there - if it is there, then /proc/cpuinfo
288 * would provide current frequency information, which is wrong.
289 */
290 if (!RTLinuxSysFsExists("devices/system/cpu/cpu%d/cpufreq/cpuinfo_max_freq", (int)idCpu))
291 kHz = rtMpLinuxGetFrequency(idCpu) * 1000;
292 else
293 kHz = 0;
294 }
295 return (kHz + 999) / 1000;
296}
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