Revert "Revert "Use eBPF-based time-in-state monitoring for groups of threads"" (8d247edc) · Commits · e / os / android_frameworks_base

core/java/com/android/internal/os/BatteryStatsImpl.java

+19 −95

Original line number	Diff line number	Diff line
		@@ -1098,16 +1098,6 @@ public class BatteryStatsImpl extends BatteryStats {

		private long[] mCpuFreqs;

		/**
		* Times spent by the system server process grouped by cluster and CPU speed.
		*/
		private LongSamplingCounterArray mSystemServerCpuTimesUs;

		/**
		* Times spent by the system server threads grouped by cluster and CPU speed.
		*/
		private LongSamplingCounterArray mSystemServerThreadCpuTimesUs;

		/**
		* Times spent by the system server threads handling incoming binder requests.
		*/
		@@ -10856,6 +10846,14 @@ public class BatteryStatsImpl extends BatteryStats {
		}
		}

		/**
		* Starts tracking CPU time-in-state for threads of the system server process,
		* keeping a separate account of threads receiving incoming binder calls.
		*/
		public void startTrackingSystemServerCpuTime() {
		mSystemServerCpuThreadReader.startTrackingThreadCpuTime();
		}

		public void setCallback(BatteryCallback cb) {
		mCallback = cb;
		}
		@@ -11508,8 +11506,6 @@ public class BatteryStatsImpl extends BatteryStats {

		MeasuredEnergyStats.resetIfNotNull(mGlobalMeasuredEnergyStats);

		resetIfNotNull(mSystemServerCpuTimesUs, false, elapsedRealtimeUs);
		resetIfNotNull(mSystemServerThreadCpuTimesUs, false, elapsedRealtimeUs);
		resetIfNotNull(mBinderThreadCpuTimesUs, false, elapsedRealtimeUs);

		mLastHistoryStepDetails = null;
		@@ -12695,27 +12691,17 @@ public class BatteryStatsImpl extends BatteryStats {
		return;
		}

		if (mSystemServerCpuTimesUs == null) {
		mSystemServerCpuTimesUs = new LongSamplingCounterArray(mOnBatteryTimeBase);
		mSystemServerThreadCpuTimesUs = new LongSamplingCounterArray(mOnBatteryTimeBase);
		if (mBinderThreadCpuTimesUs == null) {
		mBinderThreadCpuTimesUs = new LongSamplingCounterArray(mOnBatteryTimeBase);
		}
		mSystemServerCpuTimesUs.addCountLocked(systemServiceCpuThreadTimes.processCpuTimesUs);
		mSystemServerThreadCpuTimesUs.addCountLocked(systemServiceCpuThreadTimes.threadCpuTimesUs);
		mBinderThreadCpuTimesUs.addCountLocked(systemServiceCpuThreadTimes.binderThreadCpuTimesUs);

		if (DEBUG_BINDER_STATS) {
		Slog.d(TAG, "System server threads per CPU cluster (binder threads/total threads/%)");
		long totalCpuTimeMs = 0;
		long totalThreadTimeMs = 0;
		Slog.d(TAG, "System server threads per CPU cluster (incoming binder threads)");
		long binderThreadTimeMs = 0;
		int cpuIndex = 0;
		final long[] systemServerCpuTimesUs =
		mSystemServerCpuTimesUs.getCountsLocked(0);
		final long[] systemServerThreadCpuTimesUs =
		mSystemServerThreadCpuTimesUs.getCountsLocked(0);
		final long[] binderThreadCpuTimesUs =
		mBinderThreadCpuTimesUs.getCountsLocked(0);
		final long[] binderThreadCpuTimesUs = mBinderThreadCpuTimesUs.getCountsLocked(
		BatteryStats.STATS_SINCE_CHARGED);
		int index = 0;
		int numCpuClusters = mPowerProfile.getNumCpuClusters();
		for (int cluster = 0; cluster < numCpuClusters; cluster++) {
		@@ -12726,28 +12712,15 @@ public class BatteryStatsImpl extends BatteryStats {
		if (speed != 0) {
		sb.append(", ");
		}
		long totalCountMs = systemServerThreadCpuTimesUs[index] / 1000;
		long binderCountMs = binderThreadCpuTimesUs[index] / 1000;
		sb.append(String.format("%d/%d(%.1f%%)",
		binderCountMs,
		totalCountMs,
		totalCountMs != 0 ? (double) binderCountMs * 100 / totalCountMs : 0));
		sb.append(TextUtils.formatSimple("%10d", binderCountMs));

		totalCpuTimeMs += systemServerCpuTimesUs[index] / 1000;
		totalThreadTimeMs += totalCountMs;
		binderThreadTimeMs += binderCountMs;
		index++;
		}
		cpuIndex += mPowerProfile.getNumCoresInCpuCluster(cluster);
		Slog.d(TAG, sb.toString());
		}

		Slog.d(TAG, "Total system server CPU time (ms): " + totalCpuTimeMs);
		Slog.d(TAG, "Total system server thread time (ms): " + totalThreadTimeMs);
		Slog.d(TAG, String.format("Total Binder thread time (ms): %d (%.1f%%)",
		binderThreadTimeMs,
		binderThreadTimeMs != 0
		? (double) binderThreadTimeMs * 100 / totalThreadTimeMs : 0));
		}
		}

		@@ -14022,60 +13995,16 @@ public class BatteryStatsImpl extends BatteryStats {
		}


		/**
		* Estimates the time spent by the system server handling incoming binder requests.
		*/
		@Override
		public long[] getSystemServiceTimeAtCpuSpeeds() {
		// Estimates the time spent by the system server handling incoming binder requests.
		//
		// The data that we can get from the kernel is this:
		// - CPU duration for a (thread - cluster - CPU speed) combination
		// - CPU duration for a (UID - cluster - CPU speed) combination
		//
		// The configuration we have in the Power Profile is this:
		// - Average CPU power for a (cluster - CPU speed) combination.
		//
		// The model used by BatteryStats can be illustrated with this example:
		//
		// - Let's say the system server has 10 threads.
		// - These 10 threads spent 1000 ms of CPU time in aggregate
		// - Of the 10 threads 4 were execute exclusively incoming binder calls.
		// - These 4 "binder" threads consumed 600 ms of CPU time in aggregate
		// - The real time spent by the system server process doing all of this is, say, 200 ms.
		//
		// We will assume that power consumption is proportional to the time spent by the CPU
		// across all threads. This is a crude assumption, but we don't have more detailed data.
		// Thus,
		// binderRealTime = realTime * aggregateBinderThreadTime / aggregateAllThreadTime
		//
		// In our example,
		// binderRealTime = 200 * 600 / 1000 = 120ms
		//
		// We can then multiply this estimated time by the average power to obtain an estimate
		// of the total power consumed by incoming binder calls for the given cluster/speed
		// combination.

		if (mSystemServerCpuTimesUs == null) {
		if (mBinderThreadCpuTimesUs == null) {
		return null;
		}

		final long[] systemServerCpuTimesUs = mSystemServerCpuTimesUs.getCountsLocked(
		BatteryStats.STATS_SINCE_CHARGED);
		final long [] systemServerThreadCpuTimesUs = mSystemServerThreadCpuTimesUs.getCountsLocked(
		BatteryStats.STATS_SINCE_CHARGED);
		final long[] binderThreadCpuTimesUs = mBinderThreadCpuTimesUs.getCountsLocked(
		BatteryStats.STATS_SINCE_CHARGED);

		final int size = systemServerCpuTimesUs.length;
		final long[] results = new long[size];

		for (int i = 0; i < size; i++) {
		if (systemServerThreadCpuTimesUs[i] == 0) {
		continue;
		}

		results[i] = systemServerCpuTimesUs[i] * binderThreadCpuTimesUs[i]
		/ systemServerThreadCpuTimesUs[i];
		}
		return results;
		return mBinderThreadCpuTimesUs.getCountsLocked(BatteryStats.STATS_SINCE_CHARGED);
		}

		/**
		@@ -14506,7 +14435,7 @@ public class BatteryStatsImpl extends BatteryStats {
		}

		updateSystemServiceCallStats();
		if (mSystemServerThreadCpuTimesUs != null) {
		if (mBinderThreadCpuTimesUs != null) {
		pw.println("Per UID System server binder time in ms:");
		long[] systemServiceTimeAtCpuSpeeds = getSystemServiceTimeAtCpuSpeeds();
		for (int i = 0; i < size; i++) {
		@@ -16097,9 +16026,6 @@ public class BatteryStatsImpl extends BatteryStats {
		mUidStats.append(uid, u);
		}

		mSystemServerCpuTimesUs = LongSamplingCounterArray.readFromParcel(in, mOnBatteryTimeBase);
		mSystemServerThreadCpuTimesUs = LongSamplingCounterArray.readFromParcel(in,
		mOnBatteryTimeBase);
		mBinderThreadCpuTimesUs = LongSamplingCounterArray.readFromParcel(in, mOnBatteryTimeBase);
		}

		@@ -16308,8 +16234,6 @@ public class BatteryStatsImpl extends BatteryStats {
		} else {
		out.writeInt(0);
		}
		LongSamplingCounterArray.writeToParcel(out, mSystemServerCpuTimesUs);
		LongSamplingCounterArray.writeToParcel(out, mSystemServerThreadCpuTimesUs);
		LongSamplingCounterArray.writeToParcel(out, mBinderThreadCpuTimesUs);
		}

core/java/com/android/internal/os/KernelSingleProcessCpuThreadReader.java

+103 −190

Original line number	Diff line number	Diff line
		@@ -16,23 +16,12 @@

		package com.android.internal.os;

		import static android.os.Process.PROC_OUT_LONG;
		import static android.os.Process.PROC_SPACE_TERM;

		import android.annotation.Nullable;
		import android.os.Process;
		import android.system.Os;
		import android.system.OsConstants;
		import android.util.Slog;

		import com.android.internal.annotations.VisibleForTesting;

		import java.io.IOException;
		import java.nio.file.DirectoryIteratorException;
		import java.nio.file.DirectoryStream;
		import java.nio.file.Files;
		import java.nio.file.Path;
		import java.nio.file.Paths;
		import java.util.Arrays;

		/**
		@@ -45,93 +34,65 @@ public class KernelSingleProcessCpuThreadReader {
		private static final String TAG = "KernelSingleProcCpuThreadRdr";

		private static final boolean DEBUG = false;
		private static final boolean NATIVE_ENABLED = true;

		private final int mPid;

		private final CpuTimeInStateReader mCpuTimeInStateReader;

		private int[] mSelectedThreadNativeTids = new int[0]; // Sorted

		/**
		* The name of the file to read CPU statistics from, must be found in {@code
		* /proc/$PID/task/$TID}
		* Count of frequencies read from the {@code time_in_state} file.
		*/
		private static final String CPU_STATISTICS_FILENAME = "time_in_state";

		private static final String PROC_STAT_FILENAME = "stat";

		/** Directory under /proc/$PID containing CPU stats files for threads */
		public static final String THREAD_CPU_STATS_DIRECTORY = "task";

		/** Default mount location of the {@code proc} filesystem */
		private static final Path DEFAULT_PROC_PATH = Paths.get("/proc");

		/** The initial {@code time_in_state} file for {@link ProcTimeInStateReader} */
		private static final Path INITIAL_TIME_IN_STATE_PATH = Paths.get("self/time_in_state");

		/** See https://man7.org/linux/man-pages/man5/proc.5.html */
		private static final int[] PROCESS_FULL_STATS_FORMAT = new int[] {
		PROC_SPACE_TERM,
		PROC_SPACE_TERM,
		PROC_SPACE_TERM,
		PROC_SPACE_TERM,
		PROC_SPACE_TERM,
		PROC_SPACE_TERM,
		PROC_SPACE_TERM,
		PROC_SPACE_TERM,
		PROC_SPACE_TERM,
		PROC_SPACE_TERM,
		PROC_SPACE_TERM,
		PROC_SPACE_TERM,
		PROC_SPACE_TERM,
		PROC_SPACE_TERM \| PROC_OUT_LONG, // 14: utime
		PROC_SPACE_TERM \| PROC_OUT_LONG, // 15: stime
		// Ignore remaining fields
		};

		private final long[] mProcessFullStatsData = new long[2];

		private static final int PROCESS_FULL_STAT_UTIME = 0;
		private static final int PROCESS_FULL_STAT_STIME = 1;

		/** Used to read and parse {@code time_in_state} files */
		private final ProcTimeInStateReader mProcTimeInStateReader;

		private final int mPid;
		private int mFrequencyCount;

		/** Where the proc filesystem is mounted */
		private final Path mProcPath;
		private boolean mIsTracking;

		// How long a CPU jiffy is in milliseconds.
		private final long mJiffyMillis;
		/**
		* A CPU time-in-state provider for testing. Imitates the behavior of the corresponding
		* methods in frameworks/native/libs/cputimeinstate/cputimeinstate.c
		*/
		@VisibleForTesting
		public interface CpuTimeInStateReader {
		/**
		* Returns the overall number of cluster-frequency combinations.
		*/
		int getCpuFrequencyCount();

		// Path: /proc/<pid>/stat
		private final String mProcessStatFilePath;
		/**
		* Returns true to indicate success.
		*
		* Called from native.
		*/
		boolean startTrackingProcessCpuTimes(int tgid);

		// Path: /proc/<pid>/task
		private final Path mThreadsDirectoryPath;
		/**
		* Returns true to indicate success.
		*
		* Called from native.
		*/
		boolean startAggregatingTaskCpuTimes(int pid, int aggregationKey);

		/**
		* Count of frequencies read from the {@code time_in_state} file. Read from {@link
		* #mProcTimeInStateReader#getCpuFrequenciesKhz()}.
		* Must return an array of strings formatted like this:
		* "aggKey:t0_0 t0_1...:t1_0 t1_1..."
		* Times should be provided in nanoseconds.
		*
		* Called from native.
		*/
		private int mFrequencyCount;
		String[] getAggregatedTaskCpuFreqTimes(int pid);
		}

		/**
		* Create with a path where `proc` is mounted. Used primarily for testing
		*
		* @param pid PID of the process whose threads are to be read.
		* @param procPath where `proc` is mounted (to find, see {@code mount \| grep ^proc})
		*/
		@VisibleForTesting
		public KernelSingleProcessCpuThreadReader(
		int pid,
		Path procPath) throws IOException {
		public KernelSingleProcessCpuThreadReader(int pid,
		@Nullable CpuTimeInStateReader cpuTimeInStateReader) throws IOException {
		mPid = pid;
		mProcPath = procPath;
		mProcTimeInStateReader = new ProcTimeInStateReader(
		mProcPath.resolve(INITIAL_TIME_IN_STATE_PATH));
		long jiffyHz = Os.sysconf(OsConstants._SC_CLK_TCK);
		mJiffyMillis = 1000 / jiffyHz;
		mProcessStatFilePath =
		mProcPath.resolve(String.valueOf(mPid)).resolve(PROC_STAT_FILENAME).toString();
		mThreadsDirectoryPath =
		mProcPath.resolve(String.valueOf(mPid)).resolve(THREAD_CPU_STATS_DIRECTORY);
		mCpuTimeInStateReader = cpuTimeInStateReader;
		}

		/**
		@@ -142,7 +103,7 @@ public class KernelSingleProcessCpuThreadReader {
		@Nullable
		public static KernelSingleProcessCpuThreadReader create(int pid) {
		try {
		return new KernelSingleProcessCpuThreadReader(pid, DEFAULT_PROC_PATH);
		return new KernelSingleProcessCpuThreadReader(pid, null);
		} catch (IOException e) {
		Slog.e(TAG, "Failed to initialize KernelSingleProcessCpuThreadReader", e);
		return null;
		@@ -150,146 +111,98 @@ public class KernelSingleProcessCpuThreadReader {
		}

		/**
		* Get the CPU frequencies that correspond to the times reported in {@link
		* ProcessCpuUsage#processCpuTimesMillis} etc.
		* Starts tracking aggregated CPU time-in-state of all threads of the process with the PID
		* supplied in the constructor.
		*/
		public int getCpuFrequencyCount() {
		if (mFrequencyCount == 0) {
		mFrequencyCount = mProcTimeInStateReader.getFrequenciesKhz().length;
		public void startTrackingThreadCpuTimes() {
		if (!mIsTracking) {
		if (!startTrackingProcessCpuTimes(mPid, mCpuTimeInStateReader)) {
		Slog.e(TAG, "Failed to start tracking process CPU times for " + mPid);
		}
		if (mSelectedThreadNativeTids.length > 0) {
		if (!startAggregatingThreadCpuTimes(mSelectedThreadNativeTids,
		mCpuTimeInStateReader)) {
		Slog.e(TAG, "Failed to start tracking aggregated thread CPU times for "
		+ Arrays.toString(mSelectedThreadNativeTids));
		}
		}
		mIsTracking = true;
		}
		return mFrequencyCount;
		}

		/**
		* Get the total and per-thread CPU usage of the process with the PID specified in the
		* constructor.
		*
		* @param selectedThreadIds a SORTED array of native Thread IDs whose CPU times should
		* @param nativeTids an array of native Thread IDs whose CPU times should
		* be aggregated as a group. This is expected to be a subset
		* of all thread IDs owned by the process.
		*/
		@Nullable
		public ProcessCpuUsage getProcessCpuUsage(int[] selectedThreadIds) {
		if (DEBUG) {
		Slog.d(TAG, "Reading CPU thread usages with directory " + mProcPath + " process ID "
		+ mPid);
		public void setSelectedThreadIds(int[] nativeTids) {
		mSelectedThreadNativeTids = nativeTids.clone();
		if (mIsTracking) {
		startAggregatingThreadCpuTimes(mSelectedThreadNativeTids, mCpuTimeInStateReader);
		}

		int cpuFrequencyCount = getCpuFrequencyCount();
		ProcessCpuUsage processCpuUsage = new ProcessCpuUsage(cpuFrequencyCount);

		if (NATIVE_ENABLED) {
		boolean result = readProcessCpuUsage(mProcPath.toString(), mPid,
		selectedThreadIds, processCpuUsage.processCpuTimesMillis,
		processCpuUsage.threadCpuTimesMillis,
		processCpuUsage.selectedThreadCpuTimesMillis);
		if (!result) {
		return null;
		}
		return processCpuUsage;
		}

		if (!isSorted(selectedThreadIds)) {
		throw new IllegalArgumentException("selectedThreadIds is not sorted: "
		+ Arrays.toString(selectedThreadIds));
		/**
		* Get the CPU frequencies that correspond to the times reported in {@link ProcessCpuUsage}.
		*/
		public int getCpuFrequencyCount() {
		if (mFrequencyCount == 0) {
		mFrequencyCount = getCpuFrequencyCount(mCpuTimeInStateReader);
		}

		if (!Process.readProcFile(mProcessStatFilePath, PROCESS_FULL_STATS_FORMAT, null,
		mProcessFullStatsData, null)) {
		Slog.e(TAG, "Failed to read process stat file " + mProcessStatFilePath);
		return null;
		return mFrequencyCount;
		}

		long utime = mProcessFullStatsData[PROCESS_FULL_STAT_UTIME];
		long stime = mProcessFullStatsData[PROCESS_FULL_STAT_STIME];
		/**
		* Get the total CPU usage of the process with the PID specified in the
		* constructor. The CPU usage time is aggregated across all threads and may
		* exceed the time the entire process has been running.
		*/
		@Nullable
		public ProcessCpuUsage getProcessCpuUsage() {
		if (DEBUG) {
		Slog.d(TAG, "Reading CPU thread usages for PID " + mPid);
		}

		long processCpuTimeMillis = (utime + stime) * mJiffyMillis;
		ProcessCpuUsage processCpuUsage = new ProcessCpuUsage(getCpuFrequencyCount());

		try (DirectoryStream<Path> threadPaths = Files.newDirectoryStream(mThreadsDirectoryPath)) {
		for (Path threadDirectory : threadPaths) {
		readThreadCpuUsage(processCpuUsage, selectedThreadIds, threadDirectory);
		}
		} catch (IOException \| DirectoryIteratorException e) {
		// Expected when a process finishes
		boolean result = readProcessCpuUsage(mPid,
		processCpuUsage.threadCpuTimesMillis,
		processCpuUsage.selectedThreadCpuTimesMillis,
		mCpuTimeInStateReader);
		if (!result) {
		return null;
		}

		// Estimate per cluster per frequency CPU time for the entire process
		// by distributing the total process CPU time proportionately to how much
		// CPU time its threads took on those clusters/frequencies. This algorithm
		// works more accurately when when we have equally distributed concurrency.
		// TODO(b/169279846): obtain actual process CPU times from the kernel
		long totalCpuTimeAllThreads = 0;
		for (int i = cpuFrequencyCount - 1; i >= 0; i--) {
		totalCpuTimeAllThreads += processCpuUsage.threadCpuTimesMillis[i];
		}

		for (int i = cpuFrequencyCount - 1; i >= 0; i--) {
		processCpuUsage.processCpuTimesMillis[i] =
		processCpuTimeMillis * processCpuUsage.threadCpuTimesMillis[i]
		/ totalCpuTimeAllThreads;
		if (DEBUG) {
		Slog.d(TAG, "threadCpuTimesMillis = "
		+ Arrays.toString(processCpuUsage.threadCpuTimesMillis));
		Slog.d(TAG, "selectedThreadCpuTimesMillis = "
		+ Arrays.toString(processCpuUsage.selectedThreadCpuTimesMillis));
		}

		return processCpuUsage;
		}

		/**
		* Reads a thread's CPU usage and aggregates the per-cluster per-frequency CPU times.
		*
		* @param threadDirectory the {@code /proc} directory of the thread
		*/
		private void readThreadCpuUsage(ProcessCpuUsage processCpuUsage, int[] selectedThreadIds,
		Path threadDirectory) {
		// Get the thread ID from the directory name
		final int threadId;
		try {
		final String directoryName = threadDirectory.getFileName().toString();
		threadId = Integer.parseInt(directoryName);
		} catch (NumberFormatException e) {
		Slog.w(TAG, "Failed to parse thread ID when iterating over /proc/*/task", e);
		return;
		}

		// Get the CPU statistics from the directory
		final Path threadCpuStatPath = threadDirectory.resolve(CPU_STATISTICS_FILENAME);
		final long[] cpuUsages = mProcTimeInStateReader.getUsageTimesMillis(threadCpuStatPath);
		if (cpuUsages == null) {
		return;
		}

		final int cpuFrequencyCount = getCpuFrequencyCount();
		final boolean isSelectedThread = Arrays.binarySearch(selectedThreadIds, threadId) >= 0;
		for (int i = cpuFrequencyCount - 1; i >= 0; i--) {
		processCpuUsage.threadCpuTimesMillis[i] += cpuUsages[i];
		if (isSelectedThread) {
		processCpuUsage.selectedThreadCpuTimesMillis[i] += cpuUsages[i];
		}
		}
		}

		/** CPU usage of a process, all of its threads and a selected subset of its threads */
		public static class ProcessCpuUsage {
		public long[] processCpuTimesMillis;
		public long[] threadCpuTimesMillis;
		public long[] selectedThreadCpuTimesMillis;

		public ProcessCpuUsage(int cpuFrequencyCount) {
		processCpuTimesMillis = new long[cpuFrequencyCount];
		threadCpuTimesMillis = new long[cpuFrequencyCount];
		selectedThreadCpuTimesMillis = new long[cpuFrequencyCount];
		}
		}

		private static boolean isSorted(int[] array) {
		for (int i = 0; i < array.length - 1; i++) {
		if (array[i] > array[i + 1]) {
		return false;
		}
		}
		return true;
		}
		private native int getCpuFrequencyCount(CpuTimeInStateReader reader);

		private native boolean startTrackingProcessCpuTimes(int pid, CpuTimeInStateReader reader);

		private native boolean startAggregatingThreadCpuTimes(int[] selectedThreadIds,
		CpuTimeInStateReader reader);

		private native boolean readProcessCpuUsage(String procPath, int pid, int[] selectedThreadIds,
		long[] processCpuTimesMillis, long[] threadCpuTimesMillis,
		long[] selectedThreadCpuTimesMillis);
		private native boolean readProcessCpuUsage(int pid,
		long[] threadCpuTimesMillis,
		long[] selectedThreadCpuTimesMillis,
		CpuTimeInStateReader reader);
		}

core/java/com/android/internal/os/SystemServerCpuThreadReader.java

+14 −18

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core/jni/com_android_internal_os_KernelSingleProcessCpuThreadReader.cpp

+242 −178

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core/tests/coretests/src/com/android/internal/os/KernelSingleProcessCpuThreadReaderTest.java

+48 −83

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