1 files changed, 287 insertions, 0 deletions
diff --git a/tools/profiler/core/PowerCounters-linux.cpp b/tools/profiler/core/PowerCounters-linux.cpp
new file mode 100644
index 0000000000..006cea4867
--- /dev/null
+++ b/tools/profiler/core/PowerCounters-linux.cpp
@@ -0,0 +1,287 @@
+/* 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/. */
+
+#include "PowerCounters.h"
+#include "nsXULAppAPI.h"
+#include "mozilla/Maybe.h"
+#include "mozilla/Logging.h"
+
+#include <sys/syscall.h>
+#include <sys/ioctl.h>
+#include <unistd.h>
+
+#include <cerrno>
+#include <cinttypes>
+#include <cstdio>
+#include <cstdlib>
+#include <fstream>
+#include <string>
+
+#include <linux/perf_event.h>
+
+// From the kernel rapl_scale() function:
+//
+// > users must then scale back: count * 1/(1e9*2^32) to get Joules
+#define PERF_EVENT_SCALE_NANOJOULES 2.3283064365386962890625e-1
+#define SCALE_NANOJOULES_TO_PICOWATTHOUR 3.6
+#define SYSFS_PERF_POWER_TYPE_PATH "/sys/bus/event_source/devices/power/type"
+
+static mozilla::LazyLogModule sRaplEventLog("profiler.rapl");
+#define RAPL_LOG(...) \
+  MOZ_LOG(sRaplEventLog, mozilla::LogLevel::Debug, (__VA_ARGS__));
+
+enum class RaplEventType : uint64_t {
+  RAPL_ENERGY_CORES = 0x01,
+  RAPL_ENERGY_PKG = 0x02,
+  RAPL_ENERGY_DRAM = 0x03,
+  RAPL_ENERGY_GPU = 0x04,
+  RAPL_ENERGY_PSYS = 0x05,
+};
+
+struct RaplDomain {
+  RaplEventType mRaplEventType;
+  const char* mLabel;
+  const char* mDescription;
+};
+
+constexpr RaplDomain kSupportedRaplDomains[] = {
+    {RaplEventType::RAPL_ENERGY_CORES, "Power: CPU cores",
+     "Consumption of all physical cores"},
+    {
+        RaplEventType::RAPL_ENERGY_PKG,
+        "Power: CPU package",
+        "Consumption of the whole processor package",
+    },
+    {
+        RaplEventType::RAPL_ENERGY_DRAM,
+        "Power: DRAM",
+        "Consumption of the dram domain",
+    },
+    {
+        RaplEventType::RAPL_ENERGY_GPU,
+        "Power: iGPU",
+        "Consumption of the builtin-gpu domain",
+    },
+    {
+        RaplEventType::RAPL_ENERGY_PSYS,
+        "Power: System",
+        "Consumption of the builtin-psys domain",
+    }};
+
+static std::string GetSysfsFileID(RaplEventType aEventType) {
+  switch (aEventType) {
+    case RaplEventType::RAPL_ENERGY_CORES:
+      return "cores";
+    case RaplEventType::RAPL_ENERGY_PKG:
+      return "pkg";
+    case RaplEventType::RAPL_ENERGY_DRAM:
+      return "ram";
+    case RaplEventType::RAPL_ENERGY_GPU:
+      return "gpu";
+    case RaplEventType::RAPL_ENERGY_PSYS:
+      return "psys";
+  }
+
+  return "";
+}
+
+static double GetRaplPerfEventScale(RaplEventType aEventType) {
+  const std::string sysfsFileName =
+      "/sys/bus/event_source/devices/power/events/energy-" +
+      GetSysfsFileID(aEventType) + ".scale";
+  std::ifstream sysfsFile(sysfsFileName);
+
+  if (!sysfsFile) {
+    return PERF_EVENT_SCALE_NANOJOULES;
+  }
+
+  double scale;
+
+  if (sysfsFile >> scale) {
+    RAPL_LOG("Read scale from %s: %.22e", sysfsFileName.c_str(), scale);
+    return scale * 1e9;
+  }
+
+  return PERF_EVENT_SCALE_NANOJOULES;
+}
+
+static uint64_t GetRaplPerfEventConfig(RaplEventType aEventType) {
+  const std::string sysfsFileName =
+      "/sys/bus/event_source/devices/power/events/energy-" +
+      GetSysfsFileID(aEventType);
+  std::ifstream sysfsFile(sysfsFileName);
+
+  if (!sysfsFile) {
+    return static_cast<uint64_t>(aEventType);
+  }
+
+  char buffer[7] = {};
+  const std::string key = "event=";
+
+  if (!sysfsFile.get(buffer, static_cast<std::streamsize>(key.length()) + 1) ||
+      key != buffer) {
+    return static_cast<uint64_t>(aEventType);
+  }
+
+  uint64_t config;
+
+  if (sysfsFile >> std::hex >> config) {
+    RAPL_LOG("Read config from %s: 0x%" PRIx64, sysfsFileName.c_str(), config);
+    return config;
+  }
+
+  return static_cast<uint64_t>(aEventType);
+}
+
+class RaplProfilerCount final : public BaseProfilerCount {
+ public:
+  explicit RaplProfilerCount(int aPerfEventType,
+                             const RaplEventType& aPerfEventConfig,
+                             const char* aLabel, const char* aDescription)
+      : BaseProfilerCount(aLabel, nullptr, nullptr, "power", aDescription),
+        mLastResult(0),
+        mPerfEventFd(-1) {
+    RAPL_LOG("Creating RAPL Event for type: %s", mLabel);
+
+    // Optimize for ease of use and do not set an excludes value. This
+    // ensures we do not require PERF_PMU_CAP_NO_EXCLUDE.
+    struct perf_event_attr attr = {0};
+    memset(&attr, 0, sizeof(attr));
+    attr.type = aPerfEventType;
+    attr.size = sizeof(struct perf_event_attr);
+    attr.config = GetRaplPerfEventConfig(aPerfEventConfig);
+    attr.sample_period = 0;
+    attr.sample_type = PERF_SAMPLE_IDENTIFIER;
+    attr.inherit = 1;
+
+    RAPL_LOG("Config for event %s: 0x%llx", mLabel, attr.config);
+
+    mEventScale = GetRaplPerfEventScale(aPerfEventConfig);
+    RAPL_LOG("Scale for event %s: %.22e", mLabel, mEventScale);
+
+    long fd = syscall(__NR_perf_event_open, &attr, -1, 0, -1, 0);
+    if (fd < 0) {
+      RAPL_LOG("Event descriptor creation failed for event: %s", mLabel);
+      mPerfEventFd = -1;
+      return;
+    }
+
+    RAPL_LOG("Created descriptor for event: %s", mLabel)
+    mPerfEventFd = static_cast<int>(fd);
+  }
+
+  ~RaplProfilerCount() {
+    if (ValidPerfEventFd()) {
+      ioctl(mPerfEventFd, PERF_EVENT_IOC_DISABLE, 0);
+      close(mPerfEventFd);
+    }
+  }
+
+  RaplProfilerCount(const RaplProfilerCount&) = delete;
+  RaplProfilerCount& operator=(const RaplProfilerCount&) = delete;
+
+  CountSample Sample() override {
+    CountSample result = {
+        .count = 0,
+        .number = 0,
+        .isSampleNew = false,
+    };
+    mozilla::Maybe<uint64_t> raplEventResult = ReadEventFd();
+
+    if (raplEventResult.isNothing()) {
+      return result;
+    }
+
+    // We need to return picowatthour to be consistent with the Windows
+    // EMI API. As a result, the scale calculation should:
+    //
+    //  - Convert the returned value to nanojoules
+    //  - Convert nanojoules to picowatthour
+    double nanojoules =
+        static_cast<double>(raplEventResult.value()) * mEventScale;
+    double picowatthours = nanojoules / SCALE_NANOJOULES_TO_PICOWATTHOUR;
+    RAPL_LOG("Sample %s { count: %lu, last-result: %lu } = %lfJ", mLabel,
+             raplEventResult.value(), mLastResult, nanojoules * 1e-9);
+
+    result.count = static_cast<int64_t>(picowatthours);
+
+    // If the tick count is the same as the returned value or if this is the
+    // first sample, treat this sample as a duplicate.
+    result.isSampleNew =
+        (mLastResult != 0 && mLastResult != raplEventResult.value() &&
+         result.count >= 0);
+    mLastResult = raplEventResult.value();
+
+    return result;
+  }
+
+  bool ValidPerfEventFd() { return mPerfEventFd >= 0; }
+
+ private:
+  mozilla::Maybe<uint64_t> ReadEventFd() {
+    MOZ_ASSERT(ValidPerfEventFd());
+
+    uint64_t eventResult;
+    ssize_t readBytes = read(mPerfEventFd, &eventResult, sizeof(uint64_t));
+    if (readBytes != sizeof(uint64_t)) {
+      RAPL_LOG("Invalid RAPL event read size: %ld", readBytes);
+      return mozilla::Nothing();
+    }
+
+    return mozilla::Some(eventResult);
+  }
+
+  uint64_t mLastResult;
+  int mPerfEventFd;
+  double mEventScale;
+};
+
+static int GetRaplPerfEventType() {
+  FILE* fp = fopen(SYSFS_PERF_POWER_TYPE_PATH, "r");
+  if (!fp) {
+    RAPL_LOG("Open of " SYSFS_PERF_POWER_TYPE_PATH " failed");
+    return -1;
+  }
+
+  int readTypeValue = -1;
+  if (fscanf(fp, "%d", &readTypeValue) != 1) {
+    RAPL_LOG("Read of " SYSFS_PERF_POWER_TYPE_PATH " failed");
+  }
+  fclose(fp);
+
+  return readTypeValue;
+}
+
+PowerCounters::PowerCounters() {
+  if (!XRE_IsParentProcess()) {
+    // Energy meters are global, so only sample them on the parent.
+    return;
+  }
+
+  // Get the value perf_event_attr.type should be set to for RAPL
+  // perf events.
+  int perfEventType = GetRaplPerfEventType();
+  if (perfEventType < 0) {
+    RAPL_LOG("Failed to find the event type for RAPL perf events.");
+    return;
+  }
+
+  for (const auto& raplEventDomain : kSupportedRaplDomains) {
+    RaplProfilerCount* raplEvent = new RaplProfilerCount(
+        perfEventType, raplEventDomain.mRaplEventType, raplEventDomain.mLabel,
+        raplEventDomain.mDescription);
+    if (!raplEvent->ValidPerfEventFd() || !mCounters.emplaceBack(raplEvent)) {
+      delete raplEvent;
+    }
+  }
+}
+
+PowerCounters::~PowerCounters() {
+  for (auto* raplEvent : mCounters) {
+    delete raplEvent;
+  }
+  mCounters.clear();
+}
+
+void PowerCounters::Sample() {}