| /* |
| * Copyright (C) 2018 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.android.server.am; |
| |
| import static com.android.server.am.ActivityManagerDebugConfig.DEBUG_METRICS; |
| import static com.android.server.am.ActivityManagerDebugConfig.TAG_AM; |
| import static com.android.server.am.ActivityManagerDebugConfig.TAG_WITH_CLASS_NAME; |
| |
| import android.annotation.Nullable; |
| import android.os.FileUtils; |
| import android.util.Slog; |
| |
| import com.android.internal.annotations.VisibleForTesting; |
| |
| import java.io.File; |
| import java.io.IOException; |
| import java.util.Locale; |
| import java.util.regex.Matcher; |
| import java.util.regex.Pattern; |
| |
| /** |
| * Static utility methods related to {@link MemoryStat}. |
| */ |
| final class MemoryStatUtil { |
| private static final String TAG = TAG_WITH_CLASS_NAME ? "MemoryStatUtil" : TAG_AM; |
| |
| /** Path to check if device has memcg */ |
| private static final String MEMCG_TEST_PATH = "/dev/memcg/apps/memory.stat"; |
| /** Path to memory stat file for logging app start memory state */ |
| private static final String MEMORY_STAT_FILE_FMT = "/dev/memcg/apps/uid_%d/pid_%d/memory.stat"; |
| /** Path to procfs stat file for logging app start memory state */ |
| private static final String PROC_STAT_FILE_FMT = "/proc/%d/stat"; |
| |
| private static final Pattern PGFAULT = Pattern.compile("total_pgfault (\\d+)"); |
| private static final Pattern PGMAJFAULT = Pattern.compile("total_pgmajfault (\\d+)"); |
| private static final Pattern RSS_IN_BYTES = Pattern.compile("total_rss (\\d+)"); |
| private static final Pattern CACHE_IN_BYTES = Pattern.compile("total_cache (\\d+)"); |
| private static final Pattern SWAP_IN_BYTES = Pattern.compile("total_swap (\\d+)"); |
| |
| private static final int PGFAULT_INDEX = 9; |
| private static final int PGMAJFAULT_INDEX = 11; |
| private static final int RSS_IN_BYTES_INDEX = 23; |
| |
| /** True if device has memcg */ |
| private static volatile Boolean sDeviceHasMemCg; |
| |
| private MemoryStatUtil() {} |
| |
| /** |
| * Reads memory stat for a process. |
| * |
| * Reads from memcg if available on device, else fallback to procfs. |
| * Returns null if no stats can be read. |
| */ |
| @Nullable |
| static MemoryStat readMemoryStatFromFilesystem(int uid, int pid) { |
| return hasMemcg() ? readMemoryStatFromMemcg(uid, pid) : readMemoryStatFromProcfs(pid); |
| } |
| |
| /** |
| * Reads memory.stat of a process from memcg. |
| * |
| * Returns null if file is not found in memcg or if file has unrecognized contents. |
| */ |
| @Nullable |
| static MemoryStat readMemoryStatFromMemcg(int uid, int pid) { |
| final String path = String.format(Locale.US, MEMORY_STAT_FILE_FMT, uid, pid); |
| return parseMemoryStatFromMemcg(readFileContents(path)); |
| } |
| |
| /** |
| * Reads memory stat of a process from procfs. |
| * |
| * Returns null if file is not found in procfs or if file has unrecognized contents. |
| */ |
| @Nullable |
| static MemoryStat readMemoryStatFromProcfs(int pid) { |
| final String path = String.format(Locale.US, PROC_STAT_FILE_FMT, pid); |
| return parseMemoryStatFromProcfs(readFileContents(path)); |
| } |
| |
| private static String readFileContents(String path) { |
| final File file = new File(path); |
| if (!file.exists()) { |
| if (DEBUG_METRICS) Slog.i(TAG, path + " not found"); |
| return null; |
| } |
| |
| try { |
| return FileUtils.readTextFile(file, 0 /* max */, null /* ellipsis */); |
| } catch (IOException e) { |
| Slog.e(TAG, "Failed to read file:", e); |
| return null; |
| } |
| } |
| |
| /** |
| * Parses relevant statistics out from the contents of a memory.stat file in memcg. |
| */ |
| @VisibleForTesting(visibility = VisibleForTesting.Visibility.PRIVATE) |
| @Nullable |
| static MemoryStat parseMemoryStatFromMemcg(String memoryStatContents) { |
| if (memoryStatContents == null || memoryStatContents.isEmpty()) { |
| return null; |
| } |
| |
| final MemoryStat memoryStat = new MemoryStat(); |
| Matcher m; |
| m = PGFAULT.matcher(memoryStatContents); |
| memoryStat.pgfault = m.find() ? Long.valueOf(m.group(1)) : 0; |
| m = PGMAJFAULT.matcher(memoryStatContents); |
| memoryStat.pgmajfault = m.find() ? Long.valueOf(m.group(1)) : 0; |
| m = RSS_IN_BYTES.matcher(memoryStatContents); |
| memoryStat.rssInBytes = m.find() ? Long.valueOf(m.group(1)) : 0; |
| m = CACHE_IN_BYTES.matcher(memoryStatContents); |
| memoryStat.cacheInBytes = m.find() ? Long.valueOf(m.group(1)) : 0; |
| m = SWAP_IN_BYTES.matcher(memoryStatContents); |
| memoryStat.swapInBytes = m.find() ? Long.valueOf(m.group(1)) : 0; |
| return memoryStat; |
| } |
| |
| /** |
| * Parses relevant statistics out from the contents of a /proc/pid/stat file in procfs. |
| */ |
| @VisibleForTesting(visibility = VisibleForTesting.Visibility.PRIVATE) |
| @Nullable |
| static MemoryStat parseMemoryStatFromProcfs(String procStatContents) { |
| if (procStatContents == null || procStatContents.isEmpty()) { |
| return null; |
| } |
| |
| final String[] splits = procStatContents.split(" "); |
| if (splits.length < 24) { |
| return null; |
| } |
| |
| final MemoryStat memoryStat = new MemoryStat(); |
| memoryStat.pgfault = Long.valueOf(splits[PGFAULT_INDEX]); |
| memoryStat.pgmajfault = Long.valueOf(splits[PGMAJFAULT_INDEX]); |
| memoryStat.rssInBytes = Long.valueOf(splits[RSS_IN_BYTES_INDEX]); |
| return memoryStat; |
| } |
| |
| /** |
| * Checks if memcg is available on device. |
| * |
| * Touches the filesystem to do the check. |
| */ |
| static boolean hasMemcg() { |
| if (sDeviceHasMemCg == null) { |
| sDeviceHasMemCg = (new File(MEMCG_TEST_PATH)).exists(); |
| } |
| return sDeviceHasMemCg; |
| } |
| |
| static final class MemoryStat { |
| /** Number of page faults */ |
| long pgfault; |
| /** Number of major page faults */ |
| long pgmajfault; |
| /** Number of bytes of anonymous and swap cache memory */ |
| long rssInBytes; |
| /** Number of bytes of page cache memory */ |
| long cacheInBytes; |
| /** Number of bytes of swap usage */ |
| long swapInBytes; |
| } |
| } |