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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// This program provides processor power estimates. It does this by reading
+// model-specific registers (MSRs) that are part Intel's Running Average Power
+// Limit (RAPL) interface. These MSRs provide good quality estimates of the
+// energy consumption of up to four system components:
+// - PKG: the entire processor package;
+// - PP0: the cores (a subset of the package);
+// - PP1: the GPU (a subset of the package);
+// - DRAM: main memory.
+//
+// For more details about RAPL, see section 14.9 of Volume 3 of the "Intel 64
+// and IA-32 Architecture's Software Developer's Manual", Order Number 325384.
+//
+// This program exists because there are no existing tools on Mac that can
+// obtain all four RAPL estimates. (|powermetrics| can obtain the package
+// estimate, but not the others. Intel Power Gadget can obtain the package and
+// cores estimates.)
+//
+// On Linux |perf| can obtain all four estimates (as Joules, which are easily
+// converted to Watts), but this program is implemented for Linux because it's
+// not too hard to do, and that gives us multi-platform consistency.
+//
+// This program does not support Windows, unfortunately. It's not obvious how
+// to access the RAPL MSRs on Windows.
+//
+// This program deliberately uses only standard libraries and avoids
+// Mozilla-specific code, to make it easy to compile and test on different
+// machines.
+
+#include <assert.h>
+#include <getopt.h>
+#include <math.h>
+#include <signal.h>
+#include <stdarg.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/time.h>
+#include <unistd.h>
+
+#include <algorithm>
+#include <numeric>
+#include <vector>
+
+//---------------------------------------------------------------------------
+// Utilities
+//---------------------------------------------------------------------------
+
+// MOZ_FALLTHROUGH is an annotation to suppress compiler warnings about switch
+// cases that fall through without a break or return statement. MOZ_FALLTHROUGH
+// is only needed on cases that have code. This definition of MOZ_FALLTHROUGH
+// is identical to the one in mfbt/Attributes.h, which we don't use here because
+// this file avoids depending on Mozilla headers.
+#if defined(__clang__) && __cplusplus >= 201103L
+ /* clang's fallthrough annotations are only available starting in C++11. */
+# define MOZ_FALLTHROUGH [[clang::fallthrough]]
+#elif defined(_MSC_VER)
+ /*
+ * MSVC's __fallthrough annotations are checked by /analyze (Code Analysis):
+ * https://msdn.microsoft.com/en-us/library/ms235402%28VS.80%29.aspx
+ */
+# include <sal.h>
+# define MOZ_FALLTHROUGH __fallthrough
+#else
+# define MOZ_FALLTHROUGH /* FALLTHROUGH */
+#endif
+
+// The value of argv[0] passed to main(). Used in error messages.
+static const char* gArgv0;
+
+static void
+Abort(const char* aFormat, ...)
+{
+ va_list vargs;
+ va_start(vargs, aFormat);
+ fprintf(stderr, "%s: ", gArgv0);
+ vfprintf(stderr, aFormat, vargs);
+ fprintf(stderr, "\n");
+ va_end(vargs);
+
+ exit(1);
+}
+
+static void
+CmdLineAbort(const char* aMsg)
+{
+ if (aMsg) {
+ fprintf(stderr, "%s: %s\n", gArgv0, aMsg);
+ }
+ fprintf(stderr, "Use --help for more information.\n");
+ exit(1);
+}
+
+// A special value that represents an estimate from an unsupported RAPL domain.
+static const double kUnsupported_j = -1.0;
+
+// Print to stdout and flush it, so that the output appears immediately even if
+// being redirected through |tee| or anything like that.
+static void
+PrintAndFlush(const char* aFormat, ...)
+{
+ va_list vargs;
+ va_start(vargs, aFormat);
+ vfprintf(stdout, aFormat, vargs);
+ va_end(vargs);
+
+ fflush(stdout);
+}
+
+//---------------------------------------------------------------------------
+// Mac-specific code
+//---------------------------------------------------------------------------
+
+#if defined(__APPLE__)
+
+// Because of the pkg_energy_statistics_t::pkes_version check below, the
+// earliest OS X version this code will work with is 10.9.0 (xnu-2422.1.72).
+
+#include <sys/types.h>
+#include <sys/sysctl.h>
+
+// OS X has four kinds of system calls:
+//
+// 1. Mach traps;
+// 2. UNIX system calls;
+// 3. machine-dependent calls;
+// 4. diagnostic calls.
+//
+// (See "Mac OS X and iOS Internals" by Jonathan Levin for more details.)
+//
+// The last category has a single call named diagCall() or diagCall64(). Its
+// mode is controlled by its first argument, and one of the modes allows access
+// to the Intel RAPL MSRs.
+//
+// The interface to diagCall64() is not exported, so we have to import some
+// definitions from the XNU kernel. All imported definitions are annotated with
+// the XNU source file they come from, and information about what XNU versions
+// they were introduced in and (if relevant) modified.
+
+// The diagCall64() mode.
+// From osfmk/i386/Diagnostics.h
+// - In 10.8.4 (xnu-2050.24.15) this value was introduced. (In 10.8.3 the value
+// 17 was used for dgGzallocTest.)
+#define dgPowerStat 17
+
+// From osfmk/i386/cpu_data.h
+// - In 10.8.5 these values were introduced, along with core_energy_stat_t.
+#define CPU_RTIME_BINS (12)
+#define CPU_ITIME_BINS (CPU_RTIME_BINS)
+
+// core_energy_stat_t and pkg_energy_statistics_t are both from
+// osfmk/i386/Diagnostics.c.
+// - In 10.8.4 (xnu-2050.24.15) both structs were introduced, but with many
+// fewer fields.
+// - In 10.8.5 (xnu-2050.48.11) both structs were substantially expanded, with
+// numerous new fields.
+// - In 10.9.0 (xnu-2422.1.72) pkg_energy_statistics_t::pkes_version was added.
+// diagCall64(dgPowerStat) fills it with '1' in all versions since (up to
+// 10.10.2 at time of writing).
+// - in 10.10.2 (xnu-2782.10.72) core_energy_stat_t::gpmcs was conditionally
+// added, if DIAG_ALL_PMCS is true. (DIAG_ALL_PMCS is not even defined in the
+// source code, but it could be defined at compile-time via compiler flags.)
+// pkg_energy_statistics_t::pkes_version did not change, though.
+
+typedef struct {
+ uint64_t caperf;
+ uint64_t cmperf;
+ uint64_t ccres[6];
+ uint64_t crtimes[CPU_RTIME_BINS];
+ uint64_t citimes[CPU_ITIME_BINS];
+ uint64_t crtime_total;
+ uint64_t citime_total;
+ uint64_t cpu_idle_exits;
+ uint64_t cpu_insns;
+ uint64_t cpu_ucc;
+ uint64_t cpu_urc;
+#if DIAG_ALL_PMCS // Added in 10.10.2 (xnu-2782.10.72).
+ uint64_t gpmcs[4]; // Added in 10.10.2 (xnu-2782.10.72).
+#endif /* DIAG_ALL_PMCS */ // Added in 10.10.2 (xnu-2782.10.72).
+} core_energy_stat_t;
+
+typedef struct {
+ uint64_t pkes_version; // Added in 10.9.0 (xnu-2422.1.72).
+ uint64_t pkg_cres[2][7];
+
+ // This is read from MSR 0x606, which Intel calls MSR_RAPL_POWER_UNIT
+ // and XNU calls MSR_IA32_PKG_POWER_SKU_UNIT.
+ uint64_t pkg_power_unit;
+
+ // These are the four fields for the four RAPL domains. For each field
+ // we list:
+ //
+ // - the corresponding MSR number;
+ // - Intel's name for that MSR;
+ // - XNU's name for that MSR;
+ // - which Intel processors the MSR is supported on.
+ //
+ // The last of these is determined from chapter 35 of Volume 3 of the
+ // "Intel 64 and IA-32 Architecture's Software Developer's Manual",
+ // Order Number 325384. (Note that chapter 35 contradicts section 14.9
+ // to some degree.)
+
+ // 0x611 == MSR_PKG_ENERGY_STATUS == MSR_IA32_PKG_ENERGY_STATUS
+ // Atom (various), Sandy Bridge, Next Gen Xeon Phi (model 0x57).
+ uint64_t pkg_energy;
+
+ // 0x639 == MSR_PP0_ENERGY_STATUS == MSR_IA32_PP0_ENERGY_STATUS
+ // Atom (various), Sandy Bridge, Next Gen Xeon Phi (model 0x57).
+ uint64_t pp0_energy;
+
+ // 0x641 == MSR_PP1_ENERGY_STATUS == MSR_PP1_ENERGY_STATUS
+ // Sandy Bridge, Haswell.
+ uint64_t pp1_energy;
+
+ // 0x619 == MSR_DRAM_ENERGY_STATUS == MSR_IA32_DDR_ENERGY_STATUS
+ // Xeon E5, Xeon E5 v2, Haswell/Haswell-E, Next Gen Xeon Phi (model
+ // 0x57)
+ uint64_t ddr_energy;
+
+ uint64_t llc_flushed_cycles;
+ uint64_t ring_ratio_instantaneous;
+ uint64_t IA_frequency_clipping_cause;
+ uint64_t GT_frequency_clipping_cause;
+ uint64_t pkg_idle_exits;
+ uint64_t pkg_rtimes[CPU_RTIME_BINS];
+ uint64_t pkg_itimes[CPU_ITIME_BINS];
+ uint64_t mbus_delay_time;
+ uint64_t mint_delay_time;
+ uint32_t ncpus;
+ core_energy_stat_t cest[];
+} pkg_energy_statistics_t;
+
+static int
+diagCall64(uint64_t aMode, void* aBuf)
+{
+ // We cannot use syscall() here because it doesn't work with diagnostic
+ // system calls -- it raises SIGSYS if you try. So we have to use asm.
+
+#ifdef __x86_64__
+ // The 0x40000 prefix indicates it's a diagnostic system call. The 0x01
+ // suffix indicates the syscall number is 1, which also happens to be the
+ // only diagnostic system call. See osfmk/mach/i386/syscall_sw.h for more
+ // details.
+ static const uint64_t diagCallNum = 0x4000001;
+ uint64_t rv;
+
+ __asm__ __volatile__(
+ "syscall"
+
+ // Return value goes in "a" (%rax).
+ : /* outputs */ "=a"(rv)
+
+ // The syscall number goes in "0", a synonym (from outputs) for "a" (%rax).
+ // The syscall arguments go in "D" (%rdi) and "S" (%rsi).
+ : /* inputs */ "0"(diagCallNum), "D"(aMode), "S"(aBuf)
+
+ // The |syscall| instruction clobbers %rcx, %r11, and %rflags ("cc"). And
+ // this particular syscall also writes memory (aBuf).
+ : /* clobbers */ "rcx", "r11", "cc", "memory"
+ );
+ return rv;
+#else
+#error Sorry, only x86-64 is supported
+#endif
+}
+
+static void
+diagCall64_dgPowerStat(pkg_energy_statistics_t* aPkes)
+{
+ static const uint64_t supported_version = 1;
+
+ // Write an unsupported version number into pkes_version so that the check
+ // below cannot succeed by dumb luck.
+ aPkes->pkes_version = supported_version - 1;
+
+ // diagCall64() returns 1 on success, and 0 on failure (which can only happen
+ // if the mode is unrecognized, e.g. in 10.7.x or earlier versions).
+ if (diagCall64(dgPowerStat, aPkes) != 1) {
+ Abort("diagCall64() failed");
+ }
+
+ if (aPkes->pkes_version != 1) {
+ Abort("unexpected pkes_version: %llu", aPkes->pkes_version);
+ }
+}
+
+class RAPL
+{
+ bool mIsGpuSupported; // Is the GPU domain supported by the processor?
+ bool mIsRamSupported; // Is the RAM domain supported by the processor?
+
+ // The DRAM domain on Haswell servers has a fixed energy unit (1/65536 J ==
+ // 15.3 microJoules) which is different to the power unit MSR. (See the
+ // "Intel Xeon Processor E5-1600 and E5-2600 v3 Product Families, Volume 2 of
+ // 2, Registers" datasheet, September 2014, Reference Number: 330784-001.)
+ // This field records whether the quirk is present.
+ bool mHasRamUnitsQuirk;
+
+ // The abovementioned 15.3 microJoules value.
+ static const double kQuirkyRamJoulesPerTick;
+
+ // The previous sample's MSR values.
+ uint64_t mPrevPkgTicks;
+ uint64_t mPrevPp0Ticks;
+ uint64_t mPrevPp1Ticks;
+ uint64_t mPrevDdrTicks;
+
+ // The struct passed to diagCall64().
+ pkg_energy_statistics_t* mPkes;
+
+public:
+ RAPL()
+ : mHasRamUnitsQuirk(false)
+ {
+ // Work out which RAPL MSRs this CPU model supports.
+ int cpuModel;
+ size_t size = sizeof(cpuModel);
+ if (sysctlbyname("machdep.cpu.model", &cpuModel, &size, NULL, 0) != 0) {
+ Abort("sysctlbyname(\"machdep.cpu.model\") failed");
+ }
+
+ // This is similar to arch/x86/kernel/cpu/perf_event_intel_rapl.c in
+ // linux-4.1.5/.
+ switch (cpuModel) {
+ case 60: // 0x3c: Haswell
+ case 69: // 0x45: Haswell-Celeron
+ case 70: // 0x46: Haswell
+ case 61: // 0x3d: Broadwell
+ // Supports package, cores, GPU, RAM.
+ mIsGpuSupported = true;
+ mIsRamSupported = true;
+ break;
+
+ case 42: // 0x2a: Sandy Bridge
+ case 58: // 0x3a: Ivy Bridge
+ // Supports package, cores, GPU.
+ mIsGpuSupported = true;
+ mIsRamSupported = false;
+ break;
+
+ case 63: // 0x3f: Haswell-Server
+ mHasRamUnitsQuirk = true;
+ MOZ_FALLTHROUGH;
+ case 45: // 0x2d: Sandy Bridge-EP
+ case 62: // 0x3e: Ivy Bridge-E
+ // Supports package, cores, RAM.
+ mIsGpuSupported = false;
+ mIsRamSupported = true;
+ break;
+
+ default:
+ Abort("unknown CPU model: %d", cpuModel);
+ break;
+ }
+
+ // Get the maximum number of logical CPUs so that we know how big to make
+ // |mPkes|.
+ int logicalcpu_max;
+ size = sizeof(logicalcpu_max);
+ if (sysctlbyname("hw.logicalcpu_max",
+ &logicalcpu_max, &size, NULL, 0) != 0) {
+ Abort("sysctlbyname(\"hw.logicalcpu_max\") failed");
+ }
+
+ // Over-allocate by 1024 bytes per CPU to allow for the uncertainty around
+ // core_energy_stat_t::gpmcs and for any other future extensions to that
+ // struct. (The fields we read all come before the core_energy_stat_t
+ // array, so it won't matter to us whether gpmcs is present or not.)
+ size_t pkesSize = sizeof(pkg_energy_statistics_t) +
+ logicalcpu_max * sizeof(core_energy_stat_t) +
+ logicalcpu_max * 1024;
+ mPkes = (pkg_energy_statistics_t*) malloc(pkesSize);
+ if (!mPkes) {
+ Abort("malloc() failed");
+ }
+
+ // Do an initial measurement so that the first sample's diffs are sensible.
+ double dummy1, dummy2, dummy3, dummy4;
+ EnergyEstimates(dummy1, dummy2, dummy3, dummy4);
+ }
+
+ ~RAPL()
+ {
+ free(mPkes);
+ }
+
+ static double Joules(uint64_t aTicks, double aJoulesPerTick)
+ {
+ return double(aTicks) * aJoulesPerTick;
+ }
+
+ void EnergyEstimates(double& aPkg_J, double& aCores_J, double& aGpu_J,
+ double& aRam_J)
+ {
+ diagCall64_dgPowerStat(mPkes);
+
+ // Bits 12:8 are the ESU.
+ // Energy measurements come in multiples of 1/(2^ESU).
+ uint32_t energyStatusUnits = (mPkes->pkg_power_unit >> 8) & 0x1f;
+ double joulesPerTick = ((double)1 / (1 << energyStatusUnits));
+
+ aPkg_J = Joules(mPkes->pkg_energy - mPrevPkgTicks, joulesPerTick);
+ aCores_J = Joules(mPkes->pp0_energy - mPrevPp0Ticks, joulesPerTick);
+ aGpu_J = mIsGpuSupported
+ ? Joules(mPkes->pp1_energy - mPrevPp1Ticks, joulesPerTick)
+ : kUnsupported_j;
+ aRam_J = mIsRamSupported
+ ? Joules(mPkes->ddr_energy - mPrevDdrTicks,
+ mHasRamUnitsQuirk ? kQuirkyRamJoulesPerTick
+ : joulesPerTick)
+ : kUnsupported_j;
+
+ mPrevPkgTicks = mPkes->pkg_energy;
+ mPrevPp0Ticks = mPkes->pp0_energy;
+ if (mIsGpuSupported) {
+ mPrevPp1Ticks = mPkes->pp1_energy;
+ }
+ if (mIsRamSupported) {
+ mPrevDdrTicks = mPkes->ddr_energy;
+ }
+ }
+};
+
+/* static */ const double RAPL::kQuirkyRamJoulesPerTick = (double)1 / 65536;
+
+//---------------------------------------------------------------------------
+// Linux-specific code
+//---------------------------------------------------------------------------
+
+#elif defined(__linux__)
+
+#include <linux/perf_event.h>
+#include <sys/syscall.h>
+
+// There is no glibc wrapper for this system call so we provide our own.
+static int
+perf_event_open(struct perf_event_attr* aAttr, pid_t aPid, int aCpu,
+ int aGroupFd, unsigned long aFlags)
+{
+ return syscall(__NR_perf_event_open, aAttr, aPid, aCpu, aGroupFd, aFlags);
+}
+
+// Returns false if the file cannot be opened.
+template <typename T>
+static bool
+ReadValueFromPowerFile(const char* aStr1, const char* aStr2, const char* aStr3,
+ const char* aScanfString, T* aOut)
+{
+ // The filenames going into this buffer are under our control and the longest
+ // one is "/sys/bus/event_source/devices/power/events/energy-cores.scale".
+ // So 256 chars is plenty.
+ char filename[256];
+
+ sprintf(filename, "/sys/bus/event_source/devices/power/%s%s%s",
+ aStr1, aStr2, aStr3);
+ FILE* fp = fopen(filename, "r");
+ if (!fp) {
+ return false;
+ }
+ if (fscanf(fp, aScanfString, aOut) != 1) {
+ Abort("fscanf() failed");
+ }
+ fclose(fp);
+
+ return true;
+}
+
+// This class encapsulates the reading of a single RAPL domain.
+class Domain
+{
+ bool mIsSupported; // Is the domain supported by the processor?
+
+ // These three are only set if |mIsSupported| is true.
+ double mJoulesPerTick; // How many Joules each tick of the MSR represents.
+ int mFd; // The fd through which the MSR is read.
+ double mPrevTicks; // The previous sample's MSR value.
+
+public:
+ enum IsOptional { Optional, NonOptional };
+
+ Domain(const char* aName, uint32_t aType, IsOptional aOptional = NonOptional)
+ {
+ uint64_t config;
+ if (!ReadValueFromPowerFile("events/energy-", aName, "", "event=%llx",
+ &config)) {
+ // Failure is allowed for optional domains.
+ if (aOptional == NonOptional) {
+ Abort("failed to open file for non-optional domain '%s'\n"
+ "- Is your kernel version 3.14 or later, as required? "
+ "Run |uname -r| to see.", aName);
+ }
+ mIsSupported = false;
+ return;
+ }
+
+ mIsSupported = true;
+
+ ReadValueFromPowerFile("events/energy-", aName, ".scale", "%lf",
+ &mJoulesPerTick);
+
+ // The unit should be "Joules", so 128 chars should be plenty.
+ char unit[128];
+ ReadValueFromPowerFile("events/energy-", aName, ".unit", "%127s", unit);
+ if (strcmp(unit, "Joules") != 0) {
+ Abort("unexpected unit '%s' in .unit file", unit);
+ }
+
+ struct perf_event_attr attr;
+ memset(&attr, 0, sizeof(attr));
+ attr.type = aType;
+ attr.size = uint32_t(sizeof(attr));
+ attr.config = config;
+
+ // Measure all processes/threads. The specified CPU doesn't matter.
+ mFd = perf_event_open(&attr, /* aPid = */ -1, /* aCpu = */ 0,
+ /* aGroupFd = */ -1, /* aFlags = */ 0);
+ if (mFd < 0) {
+ Abort("perf_event_open() failed\n"
+ "- Did you run as root (e.g. with |sudo|) or set\n"
+ " /proc/sys/kernel/perf_event_paranoid to 0, as required?");
+ }
+
+ mPrevTicks = 0;
+ }
+
+ ~Domain()
+ {
+ if (mIsSupported) {
+ close(mFd);
+ }
+ }
+
+ double EnergyEstimate()
+ {
+ if (!mIsSupported) {
+ return kUnsupported_j;
+ }
+
+ uint64_t thisTicks;
+ if (read(mFd, &thisTicks, sizeof(uint64_t)) != sizeof(uint64_t)) {
+ Abort("read() failed");
+ }
+
+ uint64_t ticks = thisTicks - mPrevTicks;
+ mPrevTicks = thisTicks;
+ double joules = ticks * mJoulesPerTick;
+ return joules;
+ }
+};
+
+class RAPL
+{
+ Domain* mPkg;
+ Domain* mCores;
+ Domain* mGpu;
+ Domain* mRam;
+
+public:
+ RAPL()
+ {
+ uint32_t type;
+ ReadValueFromPowerFile("type", "", "", "%u", &type);
+
+ mPkg = new Domain("pkg", type);
+ mCores = new Domain("cores", type);
+ mGpu = new Domain("gpu", type, Domain::Optional);
+ mRam = new Domain("ram", type, Domain::Optional);
+ if (!mPkg || !mCores || !mGpu || !mRam) {
+ Abort("new Domain() failed");
+ }
+ }
+
+ ~RAPL()
+ {
+ delete mPkg;
+ delete mCores;
+ delete mGpu;
+ delete mRam;
+ }
+
+ void EnergyEstimates(double& aPkg_J, double& aCores_J, double& aGpu_J,
+ double& aRam_J)
+ {
+ aPkg_J = mPkg->EnergyEstimate();
+ aCores_J = mCores->EnergyEstimate();
+ aGpu_J = mGpu->EnergyEstimate();
+ aRam_J = mRam->EnergyEstimate();
+ }
+};
+
+#else
+
+//---------------------------------------------------------------------------
+// Unsupported platforms
+//---------------------------------------------------------------------------
+
+#error Sorry, this platform is not supported
+
+#endif // platform
+
+//---------------------------------------------------------------------------
+// The main loop
+//---------------------------------------------------------------------------
+
+// The sample interval, measured in seconds.
+static double gSampleInterval_sec;
+
+// The platform-specific RAPL-reading machinery.
+static RAPL* gRapl;
+
+// All the sampled "total" values, in Watts.
+static std::vector<double> gTotals_W;
+
+// Power = Energy / Time, where power is measured in Watts, Energy is measured
+// in Joules, and Time is measured in seconds.
+static double
+JoulesToWatts(double aJoules)
+{
+ return aJoules / gSampleInterval_sec;
+}
+
+// "Normalize" here means convert kUnsupported_j to zero so it can be used in
+// additive expressions. All printed values are 5 or maybe 6 chars (though 6
+// chars would require a value > 100 W, which is unlikely).
+static void
+NormalizeAndPrintAsWatts(char* aBuf, double& aValue_J)
+{
+ if (aValue_J == kUnsupported_j) {
+ aValue_J = 0;
+ sprintf(aBuf, "%s", " n/a ");
+ } else {
+ sprintf(aBuf, "%5.2f", JoulesToWatts(aValue_J));
+ }
+}
+
+static void
+SigAlrmHandler(int aSigNum, siginfo_t* aInfo, void* aContext)
+{
+ static int sampleNumber = 1;
+
+ double pkg_J, cores_J, gpu_J, ram_J;
+ gRapl->EnergyEstimates(pkg_J, cores_J, gpu_J, ram_J);
+
+ // We should have pkg and cores estimates, but might not have gpu and ram
+ // estimates.
+ assert(pkg_J != kUnsupported_j);
+ assert(cores_J != kUnsupported_j);
+
+ // This needs to be big enough to print watt values to two decimal places. 16
+ // should be plenty.
+ static const size_t kNumStrLen = 16;
+
+ static char pkgStr[kNumStrLen], coresStr[kNumStrLen], gpuStr[kNumStrLen],
+ ramStr[kNumStrLen];
+ NormalizeAndPrintAsWatts(pkgStr, pkg_J);
+ NormalizeAndPrintAsWatts(coresStr, cores_J);
+ NormalizeAndPrintAsWatts(gpuStr, gpu_J);
+ NormalizeAndPrintAsWatts(ramStr, ram_J);
+
+ // Core and GPU power are a subset of the package power.
+ assert(pkg_J >= cores_J + gpu_J);
+
+ // Compute "other" (i.e. rest of the package) and "total" only after the
+ // other values have been normalized.
+
+ char otherStr[kNumStrLen];
+ double other_J = pkg_J - cores_J - gpu_J;
+ NormalizeAndPrintAsWatts(otherStr, other_J);
+
+ char totalStr[kNumStrLen];
+ double total_J = pkg_J + ram_J;
+ NormalizeAndPrintAsWatts(totalStr, total_J);
+
+ gTotals_W.push_back(JoulesToWatts(total_J));
+
+ // Print and flush so that the output appears immediately even if being
+ // redirected through |tee| or anything like that.
+ PrintAndFlush("#%02d %s W = %s (%s + %s + %s) + %s W\n",
+ sampleNumber++, totalStr, pkgStr, coresStr, gpuStr, otherStr,
+ ramStr);
+}
+
+static void
+Finish()
+{
+ size_t n = gTotals_W.size();
+
+ // This time calculation assumes that the timers are perfectly accurate which
+ // is not true but the inaccuracy should be small in practice.
+ double time = n * gSampleInterval_sec;
+
+ printf("\n");
+ printf("%d sample%s taken over a period of %.3f second%s\n",
+ int(n), n == 1 ? "" : "s",
+ n * gSampleInterval_sec, time == 1.0 ? "" : "s");
+
+ if (n == 0 || n == 1) {
+ exit(0);
+ }
+
+ // Compute the mean.
+ double sum = std::accumulate(gTotals_W.begin(), gTotals_W.end(), 0.0);
+ double mean = sum / n;
+
+ // Compute the *population* standard deviation:
+ //
+ // popStdDev = sqrt(Sigma(x - m)^2 / n)
+ //
+ // where |x| is the sum variable, |m| is the mean, and |n| is the
+ // population size.
+ //
+ // This is different from the *sample* standard deviation, which divides by
+ // |n - 1|, and would be appropriate if we were using a random sample of a
+ // larger population.
+ double sumOfSquaredDeviations = 0;
+ for (auto iter = gTotals_W.begin(); iter != gTotals_W.end(); ++iter) {
+ double deviation = (*iter - mean);
+ sumOfSquaredDeviations += deviation * deviation;
+ }
+ double popStdDev = sqrt(sumOfSquaredDeviations / n);
+
+ // Sort so that percentiles can be determined. We use the "Nearest Rank"
+ // method of determining percentiles, which is simplest to compute and which
+ // chooses values from those that appear in the input set.
+ std::sort(gTotals_W.begin(), gTotals_W.end());
+
+ printf("\n");
+ printf("Distribution of 'total' values:\n");
+ printf(" mean = %5.2f W\n", mean);
+ printf(" std dev = %5.2f W\n", popStdDev);
+ printf(" 0th percentile = %5.2f W (min)\n", gTotals_W[0]);
+ printf(" 5th percentile = %5.2f W\n", gTotals_W[ceil(0.05 * n) - 1]);
+ printf(" 25th percentile = %5.2f W\n", gTotals_W[ceil(0.25 * n) - 1]);
+ printf(" 50th percentile = %5.2f W\n", gTotals_W[ceil(0.50 * n) - 1]);
+ printf(" 75th percentile = %5.2f W\n", gTotals_W[ceil(0.75 * n) - 1]);
+ printf(" 95th percentile = %5.2f W\n", gTotals_W[ceil(0.95 * n) - 1]);
+ printf("100th percentile = %5.2f W (max)\n", gTotals_W[n - 1]);
+
+ exit(0);
+}
+
+static void
+SigIntHandler(int aSigNum, siginfo_t* aInfo, void *aContext)
+{
+ Finish();
+}
+
+static void
+PrintUsage()
+{
+ printf(
+"usage: rapl [options]\n"
+"\n"
+"Options:\n"
+"\n"
+" -h --help show this message\n"
+" -i --sample-interval <N> sample every N ms [default=1000]\n"
+" -n --sample-count <N> get N samples (0 means unlimited) [default=0]\n"
+"\n"
+#if defined(__APPLE__)
+"On Mac this program can be run by any user.\n"
+#elif defined(__linux__)
+"On Linux this program can only be run by the super-user unless the contents\n"
+"of /proc/sys/kernel/perf_event_paranoid is set to 0 or lower.\n"
+#else
+#error Sorry, this platform is not supported
+#endif
+"\n"
+ );
+}
+
+int
+main(int argc, char** argv)
+{
+ // Process command line options.
+
+ gArgv0 = argv[0];
+
+ // Default values.
+ int sampleInterval_msec = 1000;
+ int sampleCount = 0;
+
+ struct option longOptions[] = {
+ { "help", no_argument, NULL, 'h' },
+ { "sample-interval", required_argument, NULL, 'i' },
+ { "sample-count", required_argument, NULL, 'n' },
+ { NULL, 0, NULL, 0 }
+ };
+ const char* shortOptions = "hi:n:";
+
+ int c;
+ char* endPtr;
+ while ((c = getopt_long(argc, argv, shortOptions, longOptions, NULL)) != -1) {
+ switch (c) {
+ case 'h':
+ PrintUsage();
+ exit(0);
+
+ case 'i':
+ sampleInterval_msec = strtol(optarg, &endPtr, /* base = */ 10);
+ if (*endPtr) {
+ CmdLineAbort("sample interval is not an integer");
+ }
+ if (sampleInterval_msec < 1 || sampleInterval_msec > 3600000) {
+ CmdLineAbort("sample interval must be in the range 1..3600000 ms");
+ }
+ break;
+
+ case 'n':
+ sampleCount = strtol(optarg, &endPtr, /* base = */ 10);
+ if (*endPtr) {
+ CmdLineAbort("sample count is not an integer");
+ }
+ if (sampleCount < 0 || sampleCount > 1000000) {
+ CmdLineAbort("sample count must be in the range 0..1000000");
+ }
+ break;
+
+ default:
+ CmdLineAbort(NULL);
+ }
+ }
+
+ // The RAPL MSRs update every ~1 ms, but the measurement period isn't exactly
+ // 1 ms, which means the sample periods are not exact. "Power Measurement
+ // Techniques on Standard Compute Nodes: A Quantitative Comparison" by
+ // Hackenberg et al. suggests the following.
+ //
+ // "RAPL provides energy (and not power) consumption data without
+ // timestamps associated to each counter update. This makes sampling rates
+ // above 20 Samples/s unfeasible if the systematic error should be below
+ // 5%... Constantly polling the RAPL registers will both occupy a processor
+ // core and distort the measurement itself."
+ //
+ // So warn about this case.
+ if (sampleInterval_msec < 50) {
+ fprintf(stderr,
+ "\nWARNING: sample intervals < 50 ms are likely to produce "
+ "inaccurate estimates\n\n");
+ }
+ gSampleInterval_sec = double(sampleInterval_msec) / 1000;
+
+ // Initialize the platform-specific RAPL reading machinery.
+ gRapl = new RAPL();
+ if (!gRapl) {
+ Abort("new RAPL() failed");
+ }
+
+ // Install the signal handlers.
+
+ struct sigaction sa;
+ memset(&sa, 0, sizeof(sa));
+ sa.sa_flags = SA_RESTART | SA_SIGINFO;
+ // The extra parens around (0) suppress a -Wunreachable-code warning on OS X
+ // where sigemptyset() is a macro that can never fail and always returns 0.
+ if (sigemptyset(&sa.sa_mask) < (0)) {
+ Abort("sigemptyset() failed");
+ }
+ sa.sa_sigaction = SigAlrmHandler;
+ if (sigaction(SIGALRM, &sa, NULL) < 0) {
+ Abort("sigaction(SIGALRM) failed");
+ }
+ sa.sa_sigaction = SigIntHandler;
+ if (sigaction(SIGINT, &sa, NULL) < 0) {
+ Abort("sigaction(SIGINT) failed");
+ }
+
+ // Set up the timer.
+ struct itimerval timer;
+ timer.it_interval.tv_sec = sampleInterval_msec / 1000;
+ timer.it_interval.tv_usec = (sampleInterval_msec % 1000) * 1000;
+ timer.it_value = timer.it_interval;
+ if (setitimer(ITIMER_REAL, &timer, NULL) < 0) {
+ Abort("setitimer() failed");
+ }
+
+ // Print header.
+ PrintAndFlush(" total W = _pkg_ (cores + _gpu_ + other) + _ram_ W\n");
+
+ // Take samples.
+ if (sampleCount == 0) {
+ while (true) {
+ pause();
+ }
+ } else {
+ for (int i = 0; i < sampleCount; i++) {
+ pause();
+ }
+ }
+
+ Finish();
+
+ return 0;
+}