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-rw-r--r--src/VBox/Runtime/r3/linux/mp-linux.cpp318
1 files changed, 318 insertions, 0 deletions
diff --git a/src/VBox/Runtime/r3/linux/mp-linux.cpp b/src/VBox/Runtime/r3/linux/mp-linux.cpp
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+/* $Id: mp-linux.cpp $ */
+/** @file
+ * IPRT - Multiprocessor, Linux.
+ */
+
+/*
+ * Copyright (C) 2006-2019 Oracle Corporation
+ *
+ * This file is part of VirtualBox Open Source Edition (OSE), as
+ * available from http://www.virtualbox.org. This file is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License (GPL) as published by the Free Software
+ * Foundation, in version 2 as it comes in the "COPYING" file of the
+ * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+ * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+ *
+ * The contents of this file may alternatively be used under the terms
+ * of the Common Development and Distribution License Version 1.0
+ * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
+ * VirtualBox OSE distribution, in which case the provisions of the
+ * CDDL are applicable instead of those of the GPL.
+ *
+ * You may elect to license modified versions of this file under the
+ * terms and conditions of either the GPL or the CDDL or both.
+ */
+
+
+/*********************************************************************************************************************************
+* Header Files *
+*********************************************************************************************************************************/
+#define LOG_GROUP RTLOGGROUP_SYSTEM
+#include <stdio.h>
+#include <errno.h>
+
+#include <iprt/mp.h>
+#include "internal/iprt.h"
+
+#include <iprt/alloca.h>
+#include <iprt/cpuset.h>
+#include <iprt/assert.h>
+#include <iprt/string.h>
+#include <iprt/linux/sysfs.h>
+
+
+/**
+ * Internal worker that determines the max possible CPU count.
+ *
+ * @returns Max cpus.
+ */
+static RTCPUID rtMpLinuxMaxCpus(void)
+{
+#if 0 /* this doesn't do the right thing :-/ */
+ int cMax = sysconf(_SC_NPROCESSORS_CONF);
+ Assert(cMax >= 1);
+ return cMax;
+#else
+ static uint32_t s_cMax = 0;
+ if (!s_cMax)
+ {
+ int cMax = 1;
+ for (unsigned iCpu = 0; iCpu < RTCPUSET_MAX_CPUS; iCpu++)
+ if (RTLinuxSysFsExists("devices/system/cpu/cpu%d", iCpu))
+ cMax = iCpu + 1;
+ ASMAtomicUoWriteU32((uint32_t volatile *)&s_cMax, cMax);
+ return cMax;
+ }
+ return s_cMax;
+#endif
+}
+
+/**
+ * Internal worker that picks the processor speed in MHz from /proc/cpuinfo.
+ *
+ * @returns CPU frequency.
+ */
+static uint32_t rtMpLinuxGetFrequency(RTCPUID idCpu)
+{
+ FILE *pFile = fopen("/proc/cpuinfo", "r");
+ if (!pFile)
+ return 0;
+
+ char sz[256];
+ RTCPUID idCpuFound = NIL_RTCPUID;
+ uint32_t Frequency = 0;
+ while (fgets(sz, sizeof(sz), pFile))
+ {
+ char *psz;
+ if ( !strncmp(sz, RT_STR_TUPLE("processor"))
+ && (sz[10] == ' ' || sz[10] == '\t' || sz[10] == ':')
+ && (psz = strchr(sz, ':')))
+ {
+ psz += 2;
+ int64_t iCpu;
+ int rc = RTStrToInt64Ex(psz, NULL, 0, &iCpu);
+ if (RT_SUCCESS(rc))
+ idCpuFound = iCpu;
+ }
+ else if ( idCpu == idCpuFound
+ && !strncmp(sz, RT_STR_TUPLE("cpu MHz"))
+ && (sz[10] == ' ' || sz[10] == '\t' || sz[10] == ':')
+ && (psz = strchr(sz, ':')))
+ {
+ psz += 2;
+ int64_t v;
+ int rc = RTStrToInt64Ex(psz, &psz, 0, &v);
+ if (RT_SUCCESS(rc))
+ {
+ Frequency = v;
+ break;
+ }
+ }
+ }
+ fclose(pFile);
+ return Frequency;
+}
+
+
+/** @todo RTmpCpuId(). */
+
+RTDECL(int) RTMpCpuIdToSetIndex(RTCPUID idCpu)
+{
+ return idCpu < rtMpLinuxMaxCpus() ? (int)idCpu : -1;
+}
+
+
+RTDECL(RTCPUID) RTMpCpuIdFromSetIndex(int iCpu)
+{
+ return (unsigned)iCpu < rtMpLinuxMaxCpus() ? iCpu : NIL_RTCPUID;
+}
+
+
+RTDECL(RTCPUID) RTMpGetMaxCpuId(void)
+{
+ return rtMpLinuxMaxCpus() - 1;
+}
+
+
+RTDECL(bool) RTMpIsCpuOnline(RTCPUID idCpu)
+{
+ /** @todo check if there is a simpler interface than this... */
+ int64_t i = 0;
+ int rc = RTLinuxSysFsReadIntFile(0, &i, "devices/system/cpu/cpu%d/online", (int)idCpu);
+ if ( RT_FAILURE(rc)
+ && RTLinuxSysFsExists("devices/system/cpu/cpu%d", (int)idCpu))
+ {
+ /** @todo Assert(!RTLinuxSysFsExists("devices/system/cpu/cpu%d/online",
+ * (int)idCpu));
+ * Unfortunately, the online file wasn't always world readable (centos
+ * 2.6.18-164). */
+ i = 1;
+ rc = VINF_SUCCESS;
+ }
+
+ AssertMsg(i == 0 || i == -1 || i == 1, ("i=%d\n", i));
+ return RT_SUCCESS(rc) && i != 0;
+}
+
+
+RTDECL(bool) RTMpIsCpuPossible(RTCPUID idCpu)
+{
+ /** @todo check this up with hotplugging! */
+ return RTLinuxSysFsExists("devices/system/cpu/cpu%d", (int)idCpu);
+}
+
+
+RTDECL(PRTCPUSET) RTMpGetSet(PRTCPUSET pSet)
+{
+ RTCpuSetEmpty(pSet);
+ RTCPUID cMax = rtMpLinuxMaxCpus();
+ for (RTCPUID idCpu = 0; idCpu < cMax; idCpu++)
+ if (RTMpIsCpuPossible(idCpu))
+ RTCpuSetAdd(pSet, idCpu);
+ return pSet;
+}
+
+
+RTDECL(RTCPUID) RTMpGetCount(void)
+{
+ RTCPUSET Set;
+ RTMpGetSet(&Set);
+ return RTCpuSetCount(&Set);
+}
+
+
+RTDECL(RTCPUID) RTMpGetCoreCount(void)
+{
+ RTCPUID cMax = rtMpLinuxMaxCpus();
+ uint32_t *paidCores = (uint32_t *)alloca(sizeof(paidCores[0]) * (cMax + 1));
+ uint32_t *paidPckgs = (uint32_t *)alloca(sizeof(paidPckgs[0]) * (cMax + 1));
+ uint32_t cCores = 0;
+ for (RTCPUID idCpu = 0; idCpu < cMax; idCpu++)
+ {
+ if (RTMpIsCpuPossible(idCpu))
+ {
+ int64_t idCore = 0;
+ int64_t idPckg = 0;
+
+ int rc = RTLinuxSysFsReadIntFile(0, &idCore, "devices/system/cpu/cpu%d/topology/core_id", (int)idCpu);
+ if (RT_SUCCESS(rc))
+ rc = RTLinuxSysFsReadIntFile(0, &idPckg, "devices/system/cpu/cpu%d/topology/physical_package_id", (int)idCpu);
+
+ if (RT_SUCCESS(rc))
+ {
+ uint32_t i;
+
+ for (i = 0; i < cCores; i++)
+ if ( paidCores[i] == (uint32_t)idCore
+ && paidPckgs[i] == (uint32_t)idPckg)
+ break;
+ if (i >= cCores)
+ {
+ paidCores[cCores] = (uint32_t)idCore;
+ paidPckgs[cCores] = (uint32_t)idPckg;
+ cCores++;
+ }
+ }
+ }
+ }
+ Assert(cCores > 0);
+ return cCores;
+}
+
+
+RTDECL(PRTCPUSET) RTMpGetOnlineSet(PRTCPUSET pSet)
+{
+ RTCpuSetEmpty(pSet);
+ RTCPUID cMax = rtMpLinuxMaxCpus();
+ for (RTCPUID idCpu = 0; idCpu < cMax; idCpu++)
+ if (RTMpIsCpuOnline(idCpu))
+ RTCpuSetAdd(pSet, idCpu);
+ return pSet;
+}
+
+
+RTDECL(RTCPUID) RTMpGetOnlineCount(void)
+{
+ RTCPUSET Set;
+ RTMpGetOnlineSet(&Set);
+ return RTCpuSetCount(&Set);
+}
+
+
+RTDECL(RTCPUID) RTMpGetOnlineCoreCount(void)
+{
+ RTCPUID cMax = rtMpLinuxMaxCpus();
+ uint32_t *paidCores = (uint32_t *)alloca(sizeof(paidCores[0]) * (cMax + 1));
+ uint32_t *paidPckgs = (uint32_t *)alloca(sizeof(paidPckgs[0]) * (cMax + 1));
+ uint32_t cCores = 0;
+ for (RTCPUID idCpu = 0; idCpu < cMax; idCpu++)
+ {
+ if (RTMpIsCpuOnline(idCpu))
+ {
+ int64_t idCore = 0;
+ int64_t idPckg = 0;
+
+ int rc = RTLinuxSysFsReadIntFile(0, &idCore, "devices/system/cpu/cpu%d/topology/core_id", (int)idCpu);
+ if (RT_SUCCESS(rc))
+ rc = RTLinuxSysFsReadIntFile(0, &idPckg, "devices/system/cpu/cpu%d/topology/physical_package_id", (int)idCpu);
+
+ if (RT_SUCCESS(rc))
+ {
+ uint32_t i;
+
+ for (i = 0; i < cCores; i++)
+ if ( paidCores[i] == idCore
+ && paidPckgs[i] == idPckg)
+ break;
+ if (i >= cCores)
+ {
+ paidCores[cCores] = idCore;
+ paidPckgs[cCores] = idPckg;
+ cCores++;
+ }
+ }
+ }
+ }
+ Assert(cCores > 0);
+ return cCores;
+}
+
+
+
+RTDECL(uint32_t) RTMpGetCurFrequency(RTCPUID idCpu)
+{
+ int64_t kHz = 0;
+ int rc = RTLinuxSysFsReadIntFile(0, &kHz, "devices/system/cpu/cpu%d/cpufreq/cpuinfo_cur_freq", (int)idCpu);
+ if (RT_FAILURE(rc))
+ {
+ /*
+ * The file may be just unreadable - in that case use plan B, i.e.
+ * /proc/cpuinfo to get the data we want. The assumption is that if
+ * cpuinfo_cur_freq doesn't exist then the speed won't change, and
+ * thus cur == max. If it does exist then cpuinfo contains the
+ * current frequency.
+ */
+ kHz = rtMpLinuxGetFrequency(idCpu) * 1000;
+ }
+ return (kHz + 999) / 1000;
+}
+
+
+RTDECL(uint32_t) RTMpGetMaxFrequency(RTCPUID idCpu)
+{
+ int64_t kHz = 0;
+ int rc = RTLinuxSysFsReadIntFile(0, &kHz, "devices/system/cpu/cpu%d/cpufreq/cpuinfo_max_freq", (int)idCpu);
+ if (RT_FAILURE(rc))
+ {
+ /*
+ * Check if the file isn't there - if it is there, then /proc/cpuinfo
+ * would provide current frequency information, which is wrong.
+ */
+ if (!RTLinuxSysFsExists("devices/system/cpu/cpu%d/cpufreq/cpuinfo_max_freq", (int)idCpu))
+ kHz = rtMpLinuxGetFrequency(idCpu) * 1000;
+ else
+ kHz = 0;
+ }
+ return (kHz + 999) / 1000;
+}
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