一、作用

显示内存使用情况

-S dump SwapPss

二、概念与名词

USS：进程独占内存
PSS：USS+共享内存/共享进程数
RSS：USS+共享内存
VSS：RSS+未分配的实际物理内存

三、效果展示

Total PSS by process:41743 kB: com.csr.BTApp (pid 1078)36924 kB: com.android.launcher (pid 2683)35452 kB: android.process.acore (pid 1042)16094 kB: system (pid 782)11609 kB: com.android.systemui (pid 851)8564 kB: com.baidu.input (pid 2999)5298 kB: com.android.phone (pid 959)4443 kB: com.apical.dreamthemetime (pid 4448)4203 kB: com.csr.csrservices (pid 982)4130 kB: com.apical.apicalradio (pid 4518)Total PSS by OOM adjustment:16094 kB: System16094 kB: system (pid 782)21110 kB: Persistent11609 kB: com.android.systemui (pid 851)5298 kB: com.android.phone (pid 959)4203 kB: com.csr.csrservices (pid 982)36924 kB: Foreground36924 kB: com.android.launcher (pid 2683)85759 kB: Perceptible41743 kB: com.csr.BTApp (pid 1078)35452 kB: android.process.acore (pid 1042)8564 kB: com.baidu.input (pid 2999)4443 kB: A Services4443 kB: com.apical.dreamthemetime (pid 4448)4130 kB: Background4130 kB: com.apical.apicalradio (pid 4518)Total PSS by category:56020 kB: Dalvik30214 kB: Other dev27716 kB: Native24504 kB: Cursor13198 kB: Unknown7723 kB: Other mmap6895 kB: .so mmap1232 kB: .apk mmap888 kB: .dex mmap36 kB: .ttf mmap34 kB: Ashmem0 kB: .jar mmapTotal PSS: 168460 kB

四、原理

最终PSS，RSS的信息来自/proc/$pid/smaps

最后的totoal等信息来自/proc/meminfo的信息

五、流程

1、注册服务

public static void main(String[] args) {// MIUI ADD: Init miui service stubsSystemServerStub.get();new SystemServer().run();}private void run() {// Start services.try {t.traceBegin("StartServices");startBootstrapServices(t);//跳转startCoreServices(t);startOtherServices(t);} catch (Throwable ex) {Slog.e("System", "******************************************");Slog.e("System", "************ Failure starting system services", ex);throw ex;} finally {t.traceEnd(); // StartServices}}private void startBootstrapServices(@NonNull TimingsTraceAndSlog t) {mActivityManagerService = ActivityManagerService.Lifecycle.startService(mSystemServiceManager, atm);......// Set up the Application instance for the system process and get started.t.traceBegin("SetSystemProcess");mActivityManagerService.setSystemProcess();//跳转t.traceEnd();}

public void setSystemProcess() {   ...ServiceManager.addService("meminfo", new MemBinder(this));//其中meminfo服务注册将调用MemBinder的相关方法
}

2、服务调用

main() //type=Type::DUMP

--|Dumpsys::main(int argc, char* const argv[]) //参数 meminfo -S

----|Dumpsys::startDumpThread(Type type, const String16& serviceName,const Vector<String16>& args)

------|service->dump(remote_end.get(), args) //meminfo对应远程服务dumpApplicationMemoryUsage

--------| mActivityManagerService.dumpApplicationMemoryUsage(fd, pw, " ", args, false, null,asProto)

----------|dumpApplicationMemoryUsage(fd, pw, prefix, opts, innerArgs, brief, procs, categoryPw)

------------|dumpApplicationMemoryUsageHeader(pw, uptime, realtime,opts.isCheckinRequest, opts.isCompact)

------------|Debug.getMemoryInfo(pid, mi)//native,在cpp中实现

--------------|android_os_Debug_getDirtyPagesPid(JNIEnv *env, jobject clazz,jint pid, jobject object)

----------------|load_maps(pid, stats, &foundSwapPss)

----------------|read_memtrack_memory(pid, &graphics_mem)

------------|对获取的内存信息按照顺序和格式进行输出展示

----|Dumpsys::stopDumpThread(dumpComplete);

在ActivityManagerService.java中

if (collectNative) {//打印所有进程内存信息执行的代码块mi = null;final Debug.MemoryInfo[] memInfos = new Debug.MemoryInfo[1];mAppProfiler.forAllCpuStats((st) -> {if (st.vsize > 0 && procMemsMap.indexOfKey(st.pid) < 0) {long memtrackGraphics = 0;long memtrackGl = 0;if (memInfos[0] == null) {memInfos[0] = new Debug.MemoryInfo();}final Debug.MemoryInfo info = memInfos[0];if (!brief && !opts.oomOnly) {if (!Debug.getMemoryInfo(st.pid, info)) {return;}memtrackGraphics = info.getOtherPrivate(Debug.MemoryInfo.OTHER_GRAPHICS);memtrackGl = info.getOtherPrivate(Debug.MemoryInfo.OTHER_GL);} else {long pss = Debug.getPss(st.pid, tmpLong, memtrackTmp);if (pss == 0) {return;}info.nativePss = (int) pss;info.nativePrivateDirty = (int) tmpLong[0];info.nativeRss = (int) tmpLong[2];memtrackGraphics = memtrackTmp[1];memtrackGl = memtrackTmp[2];}final long myTotalPss = info.getTotalPss();final long myTotalSwapPss = info.getTotalSwappedOutPss();final long myTotalRss = info.getTotalRss();ss[INDEX_TOTAL_PSS] += myTotalPss;ss[INDEX_TOTAL_SWAP_PSS] += myTotalSwapPss;ss[INDEX_TOTAL_RSS] += myTotalRss;ss[INDEX_TOTAL_NATIVE_PSS] += myTotalPss;ss[INDEX_TOTAL_MEMTRACK_GRAPHICS] += memtrackGraphics;ss[INDEX_TOTAL_MEMTRACK_GL] += memtrackGl;MemItem pssItem = new MemItem(st.name + " (pid " + st.pid + ")",st.name, myTotalPss, info.getSummaryTotalSwapPss(), myTotalRss,st.pid, false);procMems.add(pssItem);ss[INDEX_NATIVE_PSS] += info.nativePss;ss[INDEX_NATIVE_SWAP_PSS] += info.nativeSwappedOutPss;ss[INDEX_NATIVE_RSS] += info.nativeRss;ss[INDEX_DALVIK_PSS] += info.dalvikPss;ss[INDEX_DALVIK_SWAP_PSS] += info.dalvikSwappedOutPss;ss[INDEX_DALVIK_RSS] += info.dalvikRss;for (int j = 0; j < dalvikSubitemPss.length; j++) {//其他类型的Pss的值，具体后面在Java到native的参数传递时会讲到dalvikSubitemPss[j] += info.getOtherPss(Debug.MemoryInfo.NUM_OTHER_STATS + j);dalvikSubitemSwapPss[j] +=info.getOtherSwappedOutPss(Debug.MemoryInfo.NUM_OTHER_STATS + j);dalvikSubitemRss[j] += info.getOtherRss(Debug.MemoryInfo.NUM_OTHER_STATS+ j);}ss[INDEX_OTHER_PSS] += info.otherPss;ss[INDEX_OTHER_SWAP_PSS] += info.otherSwappedOutPss;ss[INDEX_OTHER_RSS] += info.otherRss;for (int j = 0; j < Debug.MemoryInfo.NUM_OTHER_STATS; j++) {long mem = info.getOtherPss(j);miscPss[j] += mem;ss[INDEX_OTHER_PSS] -= mem;mem = info.getOtherSwappedOutPss(j);miscSwapPss[j] += mem;ss[INDEX_OTHER_SWAP_PSS] -= mem;mem = info.getOtherRss(j);miscRss[j] += mem;ss[INDEX_OTHER_RSS] -= mem;}oomPss[0] += myTotalPss;oomSwapPss[0] += myTotalSwapPss;if (oomProcs[0] == null) {oomProcs[0] = new ArrayList<MemItem>();}oomProcs[0].add(pssItem);oomRss[0] += myTotalRss;}});ArrayList<MemItem> catMems = new ArrayList<MemItem>();catMems.add(new MemItem("Native", "Native",ss[INDEX_NATIVE_PSS], ss[INDEX_NATIVE_SWAP_PSS], ss[INDEX_NATIVE_RSS], -1));final int dalvikId = -2;catMems.add(new MemItem("Dalvik", "Dalvik", ss[INDEX_DALVIK_PSS],ss[INDEX_DALVIK_SWAP_PSS], ss[INDEX_DALVIK_RSS], dalvikId));catMems.add(new MemItem("Unknown", "Unknown", ss[INDEX_OTHER_PSS],ss[INDEX_OTHER_SWAP_PSS], ss[INDEX_OTHER_RSS], -3));for (int j=0; j<Debug.MemoryInfo.NUM_OTHER_STATS; j++) {String label = Debug.MemoryInfo.getOtherLabel(j);catMems.add(new MemItem(label, label, miscPss[j], miscSwapPss[j], miscRss[j],  j));}if (dalvikSubitemPss.length > 0) {// Add dalvik subitems.for (MemItem memItem : catMems) {int memItemStart = 0, memItemEnd = 0;if (memItem.id == dalvikId) {memItemStart = Debug.MemoryInfo.OTHER_DVK_STAT_DALVIK_START;memItemEnd = Debug.MemoryInfo.OTHER_DVK_STAT_DALVIK_END;} else if (memItem.id == Debug.MemoryInfo.OTHER_DALVIK_OTHER) {memItemStart = Debug.MemoryInfo.OTHER_DVK_STAT_DALVIK_OTHER_START;memItemEnd = Debug.MemoryInfo.OTHER_DVK_STAT_DALVIK_OTHER_END;} else if (memItem.id == Debug.MemoryInfo.OTHER_DEX) {memItemStart = Debug.MemoryInfo.OTHER_DVK_STAT_DEX_START;memItemEnd = Debug.MemoryInfo.OTHER_DVK_STAT_DEX_END;} else if (memItem.id == Debug.MemoryInfo.OTHER_ART) {memItemStart = Debug.MemoryInfo.OTHER_DVK_STAT_ART_START;memItemEnd = Debug.MemoryInfo.OTHER_DVK_STAT_ART_END;} else {continue;  // No subitems, continue.}memItem.subitems = new ArrayList<MemItem>();for (int j=memItemStart; j<=memItemEnd; j++) {final String name = Debug.MemoryInfo.getOtherLabel(Debug.MemoryInfo.NUM_OTHER_STATS + j);memItem.subitems.add(new MemItem(name, name, dalvikSubitemPss[j],dalvikSubitemSwapPss[j], dalvikSubitemRss[j], j));}}}ArrayList<MemItem> oomMems = new ArrayList<MemItem>();for (int j=0; j<oomPss.length; j++) {if (oomPss[j] != 0) {String label = opts.isCompact ? DUMP_MEM_OOM_COMPACT_LABEL[j]: DUMP_MEM_OOM_LABEL[j];MemItem item = new MemItem(label, label, oomPss[j], oomSwapPss[j], oomRss[j],DUMP_MEM_OOM_ADJ[j]);item.subitems = oomProcs[j];oomMems.add(item);}}if (!opts.isCompact) {pw.println();}if (!brief && !opts.oomOnly && !opts.isCompact) {pw.println();pw.println("Total RSS by process:");dumpMemItems(pw, "  ", "proc", procMems, true, opts.isCompact, false, false);pw.println();}if (!opts.isCompact) {pw.println("Total RSS by OOM adjustment:");}dumpMemItems(pw, "  ", "oom", oomMems, false, opts.isCompact, false, false);if (!brief && !opts.oomOnly) {PrintWriter out = categoryPw != null ? categoryPw : pw;if (!opts.isCompact) {out.println();out.println("Total RSS by category:");}dumpMemItems(out, "  ", "cat", catMems, true, opts.isCompact, false, false);}//输入的-S在这里起作用，opts.dumpSwapPss=true，这样由swapPss就会一起打印出来opts.dumpSwapPss = opts.dumpSwapPss && hasSwapPss && ss[INDEX_TOTAL_SWAP_PSS] != 0;if (!brief && !opts.oomOnly && !opts.isCompact) {pw.println();pw.println("Total PSS by process:");//关键打印按照PSS的大小的顺序进行排序打印dumpMemItems(pw, "  ", "proc", procMems, true, opts.isCompact, true,opts.dumpSwapPss);//此函数用于打印按照PSS大小顺序排列的所有进程的memory信息pw.println();}if (!opts.isCompact) {pw.println("Total PSS by OOM adjustment:");}dumpMemItems(pw, "  ", "oom", oomMems, false, opts.isCompact, true, opts.dumpSwapPss);if (!brief && !opts.oomOnly) {PrintWriter out = categoryPw != null ? categoryPw : pw;if (!opts.isCompact) {out.println();out.println("Total PSS by category:");}dumpMemItems(out, "  ", "cat", catMems, true, opts.isCompact, true,opts.dumpSwapPss);}if (!opts.isCompact) {pw.println();}MemInfoReader memInfo = new MemInfoReader();//获取系统内存总体信息，从/proc/meminfo文件中读取信息memInfo.readMemInfo();if (ss[INDEX_TOTAL_NATIVE_PSS] > 0) {synchronized (mProcessStats.mLock) {final long cachedKb = memInfo.getCachedSizeKb();final long freeKb = memInfo.getFreeSizeKb();final long zramKb = memInfo.getZramTotalSizeKb();final long kernelKb = memInfo.getKernelUsedSizeKb();EventLogTags.writeAmMeminfo(cachedKb * 1024, freeKb * 1024, zramKb * 1024,kernelKb * 1024, ss[INDEX_TOTAL_NATIVE_PSS] * 1024);mProcessStats.addSysMemUsageLocked(cachedKb, freeKb, zramKb, kernelKb,ss[INDEX_TOTAL_NATIVE_PSS]);}}if (!brief) {if (!opts.isCompact) {pw.print("Total RAM: "); pw.print(stringifyKBSize(memInfo.getTotalSizeKb()));pw.print(" (status ");mAppProfiler.dumpLastMemoryLevelLocked(pw);pw.print(" Free RAM: ");/*free mem = cached pss + cached kernel + free + ion cached + gpu cached（系统cached APP PSS总和 + meminfo的MemFree + Cached +Buffers-Mapped + meminfo的display ion和gpu模块的内存占用*/pw.print(stringifyKBSize(cachedPss + memInfo.getMoreCachedSizeKb()+ memInfo.getFreeSizeKb()));// pw.print(stringifyKBSize(cachedPss + memInfo.getCachedSizeKb()//         + memInfo.getFreeSizeKb()));pw.print(" (");pw.print(stringifyKBSize(cachedPss));pw.print(" cached pss + ");pw.print(stringifyKBSize(memInfo.getMoreCachedSizeKb()));// pw.print(stringifyKBSize(memInfo.getCachedSizeKb()));pw.print(" cached kernel + ");pw.print(stringifyKBSize(memInfo.getFreeSizeKb()));pw.println(" free)");} else {pw.print("ram,"); pw.print(memInfo.getTotalSizeKb()); pw.print(",");pw.print(cachedPss + memInfo.getMoreCachedSizeKb()+ memInfo.getFreeSizeKb()); pw.print(",");// pw.print(cachedPss + memInfo.getCachedSizeKb()//         + memInfo.getFreeSizeKb()); pw.print(",");pw.println(ss[INDEX_TOTAL_PSS] - cachedPss);}}long kernelUsed = memInfo.getKernelUsedSizeKb();final long ionHeap = Debug.getIonHeapsSizeKb();final long ionPool = Debug.getIonPoolsSizeKb();final long dmabufMapped = Debug.getDmabufMappedSizeKb();if (ionHeap >= 0 && ionPool >= 0) {final long ionUnmapped = ionHeap - dmabufMapped;pw.print("      ION: ");pw.print(stringifyKBSize(ionHeap + ionPool));pw.print(" (");pw.print(stringifyKBSize(dmabufMapped));pw.print(" mapped + ");pw.print(stringifyKBSize(ionUnmapped));pw.print(" unmapped + ");pw.print(stringifyKBSize(ionPool));pw.println(" pools)");kernelUsed += ionUnmapped;// Note: mapped ION memory is not accounted in PSS due to VM_PFNMAP flag being// set on ION VMAs, however it might be included by the memtrack HAL.// Replace memtrack HAL reported Graphics category with mapped dmabufsss[INDEX_TOTAL_PSS] -= ss[INDEX_TOTAL_MEMTRACK_GRAPHICS];ss[INDEX_TOTAL_PSS] += dmabufMapped;} else {final long totalExportedDmabuf = Debug.getDmabufTotalExportedKb();if (totalExportedDmabuf >= 0) {final long dmabufUnmapped = totalExportedDmabuf - dmabufMapped;pw.print("DMA-BUF: ");pw.print(stringifyKBSize(totalExportedDmabuf));pw.print(" (");pw.print(stringifyKBSize(dmabufMapped));pw.print(" mapped + ");pw.print(stringifyKBSize(dmabufUnmapped));pw.println(" unmapped)");// Account unmapped dmabufs as part of kernel memory allocationskernelUsed += dmabufUnmapped;// Replace memtrack HAL reported Graphics category with mapped dmabufsss[INDEX_TOTAL_PSS] -= ss[INDEX_TOTAL_MEMTRACK_GRAPHICS];ss[INDEX_TOTAL_PSS] += dmabufMapped;}// totalDmabufHeapExported is included in totalExportedDmabuf above and hence do not// need to be added to kernelUsed.final long totalDmabufHeapExported = Debug.getDmabufHeapTotalExportedKb();if (totalDmabufHeapExported >= 0) {pw.print("DMA-BUF Heaps: ");pw.println(stringifyKBSize(totalDmabufHeapExported));}final long totalDmabufHeapPool = Debug.getDmabufHeapPoolsSizeKb();if (totalDmabufHeapPool >= 0) {pw.print("DMA-BUF Heaps pool: ");pw.println(stringifyKBSize(totalDmabufHeapPool));}}final long gpuUsage = Debug.getGpuTotalUsageKb();if (gpuUsage >= 0) {final long gpuPrivateUsage = Debug.getGpuPrivateMemoryKb();if (gpuPrivateUsage >= 0) {final long gpuDmaBufUsage = gpuUsage - gpuPrivateUsage;pw.print("      GPU: ");pw.print(stringifyKBSize(gpuUsage));pw.print(" (");pw.print(stringifyKBSize(gpuDmaBufUsage));pw.print(" dmabuf + ");pw.print(stringifyKBSize(gpuPrivateUsage));pw.println(" private)");// Replace memtrack HAL reported GL category with private GPU allocations and// account it as part of kernel memory allocationsss[INDEX_TOTAL_PSS] -= ss[INDEX_TOTAL_MEMTRACK_GL];kernelUsed += gpuPrivateUsage;} else {pw.print("      GPU: "); pw.println(stringifyKBSize(gpuUsage));}}// Note: ION/DMA-BUF heap pools are reclaimable and hence, they are included as part of// memInfo.getCachedSizeKb().final long lostRAM = memInfo.getTotalSizeKb()- (ss[INDEX_TOTAL_PSS] - ss[INDEX_TOTAL_SWAP_PSS])- memInfo.getFreeSizeKb() - memInfo.getCachedSizeKb()- kernelUsed - memInfo.getZramTotalSizeKb();if (!opts.isCompact) {pw.print(" Used RAM: "); pw.print(stringifyKBSize(ss[INDEX_TOTAL_PSS] - cachedPss+ kernelUsed)); pw.print(" (");pw.print(stringifyKBSize(ss[INDEX_TOTAL_PSS] - cachedPss)); pw.print(" used pss + ");pw.print(stringifyKBSize(kernelUsed)); pw.print(" kernel)\n");pw.print(" Lost RAM: "); pw.println(stringifyKBSize(lostRAM));} else {pw.print("lostram,"); pw.println(lostRAM);}if (!brief) {if (memInfo.getZramTotalSizeKb() != 0) {if (!opts.isCompact) {pw.print("     ZRAM: ");pw.print(stringifyKBSize(memInfo.getZramTotalSizeKb()));pw.print(" physical used for ");pw.print(stringifyKBSize(memInfo.getSwapTotalSizeKb()- memInfo.getSwapFreeSizeKb()));pw.print(" in swap (");pw.print(stringifyKBSize(memInfo.getSwapTotalSizeKb()));pw.println(" total swap)");} else {pw.print("zram,"); pw.print(memInfo.getZramTotalSizeKb()); pw.print(",");pw.print(memInfo.getSwapTotalSizeKb()); pw.print(",");pw.println(memInfo.getSwapFreeSizeKb());}}final long[] ksm = getKsmInfo();if (!opts.isCompact) {if (ksm[KSM_SHARING] != 0 || ksm[KSM_SHARED] != 0 || ksm[KSM_UNSHARED] != 0|| ksm[KSM_VOLATILE] != 0) {pw.print("      KSM: "); pw.print(stringifyKBSize(ksm[KSM_SHARING]));pw.print(" saved from shared ");pw.print(stringifyKBSize(ksm[KSM_SHARED]));pw.print("           "); pw.print(stringifyKBSize(ksm[KSM_UNSHARED]));pw.print(" unshared; ");pw.print(stringifyKBSize(ksm[KSM_VOLATILE])); pw.println(" volatile");}pw.print("   Tuning: ");pw.print(ActivityManager.staticGetMemoryClass());pw.print(" (large ");pw.print(ActivityManager.staticGetLargeMemoryClass());pw.print("), oom ");pw.print(stringifySize(mProcessList.getMemLevel(ProcessList.CACHED_APP_MAX_ADJ), 1024));pw.print(", restore limit ");pw.print(stringifyKBSize(mProcessList.getCachedRestoreThresholdKb()));if (ActivityManager.isLowRamDeviceStatic()) {pw.print(" (low-ram)");}if (ActivityManager.isHighEndGfx()) {pw.print(" (high-end-gfx)");}pw.println();} else {pw.print("ksm,"); pw.print(ksm[KSM_SHARING]); pw.print(",");pw.print(ksm[KSM_SHARED]); pw.print(","); pw.print(ksm[KSM_UNSHARED]);pw.print(","); pw.println(ksm[KSM_VOLATILE]);pw.print("tuning,");pw.print(ActivityManager.staticGetMemoryClass());pw.print(',');pw.print(ActivityManager.staticGetLargeMemoryClass());pw.print(',');pw.print(mProcessList.getMemLevel(ProcessList.CACHED_APP_MAX_ADJ)/1024);if (ActivityManager.isLowRamDeviceStatic()) {pw.print(",low-ram");}if (ActivityManager.isHighEndGfx()) {pw.print(",high-end-gfx");}pw.println();}}
}

具体每个进程的读取细节在android_os_Debug.cpp中，android_os_Debug_getDirtyPagesPid函数读取proc/pid/smaps中的信息以及gl、egl，并按照类型存入

static jboolean android_os_Debug_getDirtyPagesPid(JNIEnv *env, jobject clazz,jint pid, jobject object)
{bool foundSwapPss;stats_t stats[_NUM_HEAP];memset(&stats, 0, sizeof(stats));//读取节点proc/pid/smaps节点的信息smaps.txt，统计结果保存在stats_t数组中if (!load_maps(pid, stats, &foundSwapPss)) {return JNI_FALSE;}/*根据 pid 获取 Graphic 内存，赋值到 graphics_mem 中,补充了smaps中没有的index：17，18，19。至此0～19分类对应的数值填写完毕。这部分数据获取原理https://blog.csdn.net/msf568834002/article/details/78881341https://www.cnblogs.com/pyjetson/p/14769359.html#23-read_memtrack_memory*/if (read_memtrack_memory(pid, &graphics_mem) == 0) {stats[HEAP_GRAPHICS].pss = graphics_mem.graphics;stats[HEAP_GRAPHICS].privateDirty = graphics_mem.graphics;stats[HEAP_GRAPHICS].rss = graphics_mem.graphics;stats[HEAP_GL].pss = graphics_mem.gl;stats[HEAP_GL].privateDirty = graphics_mem.gl;stats[HEAP_GL].rss = graphics_mem.gl;stats[HEAP_OTHER_MEMTRACK].pss = graphics_mem.other;stats[HEAP_OTHER_MEMTRACK].privateDirty = graphics_mem.other;stats[HEAP_OTHER_MEMTRACK].rss = graphics_mem.other;}/*NUM_CORE_HEAP=HEAP_NATIVE+1=3_NUM_EXCLUSIVE_HEAP=HEAP_OTHER_MEMTRACK+1=20。因此这段代码的意思是把3～19的数据累加到0(HEAP_UNKNOWN)中*/for (int i=_NUM_CORE_HEAP; i<_NUM_EXCLUSIVE_HEAP; i++) {stats[HEAP_UNKNOWN].pss += stats[i].pss;stats[HEAP_UNKNOWN].swappablePss += stats[i].swappablePss;stats[HEAP_UNKNOWN].rss += stats[i].rss;stats[HEAP_UNKNOWN].privateDirty += stats[i].privateDirty;stats[HEAP_UNKNOWN].sharedDirty += stats[i].sharedDirty;stats[HEAP_UNKNOWN].privateClean += stats[i].privateClean;stats[HEAP_UNKNOWN].sharedClean += stats[i].sharedClean;stats[HEAP_UNKNOWN].swappedOut += stats[i].swappedOut;stats[HEAP_UNKNOWN].swappedOutPss += stats[i].swappedOutPss;}/*使用 stats 的值对 JNI 传过来的 Java 对象进行赋值  HEAP_UNKNOWN（0）、HEAP_DALVIK（1）、HEAP_NATIVE（2）由于上一段代码已经将下标3～19的数据都记录到了unkown中，因此现在这三个下标实际上已经包含0～19的数据。分别保存在stat_fields[0]/[1]/[2]*/for (int i=0; i<_NUM_CORE_HEAP; i++) {env->SetIntField(object, stat_fields[i].pss_field, stats[i].pss);env->SetIntField(object, stat_fields[i].pssSwappable_field, stats[i].swappablePss);env->SetIntField(object, stat_fields[i].rss_field, stats[i].rss);env->SetIntField(object, stat_fields[i].privateDirty_field, stats[i].privateDirty);env->SetIntField(object, stat_fields[i].sharedDirty_field, stats[i].sharedDirty);env->SetIntField(object, stat_fields[i].privateClean_field, stats[i].privateClean);env->SetIntField(object, stat_fields[i].sharedClean_field, stats[i].sharedClean);env->SetIntField(object, stat_fields[i].swappedOut_field, stats[i].swappedOut);env->SetIntField(object, stat_fields[i].swappedOutPss_field, stats[i].swappedOutPss);}//foundSwapPss 在 load_smaps 判断 swap_pss 是否大于 0env->SetBooleanField(object, hasSwappedOutPss_field, foundSwapPss);// 对 Java 中 Meminfo对象 otherStats field 进行赋值   jintArray otherIntArray = (jintArray)env->GetObjectField(object, otherStats_field);// 获取 Java 对象 otherStats 指针jint* otherArray = (jint*)env->GetPrimitiveArrayCritical(otherIntArray, 0);if (otherArray == NULL) {return JNI_FALSE;}int j=0;/* 这里 Java otherStats 对象是一个 int[32*9]，用一个数组对象进行存储多个数据将stats数组下标 3～35的数据存入otherArray中。这里会重复数据，因为heap和subheap的下标都在注意：这在传回去之后以后就有了3的偏移。*/for (int i=_NUM_CORE_HEAP; i<_NUM_HEAP; i++) {otherArray[j++] = stats[i].pss;otherArray[j++] = stats[i].swappablePss;otherArray[j++] = stats[i].rss;otherArray[j++] = stats[i].privateDirty;otherArray[j++] = stats[i].sharedDirty;otherArray[j++] = stats[i].privateClean;otherArray[j++] = stats[i].sharedClean;otherArray[j++] = stats[i].swappedOut;otherArray[j++] = stats[i].swappedOutPss;}// 对 Java 对象 otherStats 指针的操作进行 releaseenv->ReleasePrimitiveArrayCritical(otherIntArray, otherArray, 0);return JNI_TRUE;
}

其中，stats_t类型：


struct stats_t {int pss;//MemUsage.pss累加/*如果该VMA的is_swappable==true计算共享率sharing_proportion=(MemUsage.pss - MemUsage.uss) / (MemUsage.shared_clean + MemUsage.shared_dirty);swapable_pss = (sharing_proportion * MemUsage.shared_clean) + MemUsage.private_clean;累加如果is_swappable不为true，该项为0*/int swappablePss;int rss;//MemUsage.rss累加int privateDirty;//MemUsage.private_dirty累加int sharedDirty;//MemUsage.shared_dirty累加int privateClean;//MemUsage.private_clean累加int sharedClean;//MemUsage.shared_clean累加int swappedOut;//MemUsage.swap累加int swappedOutPss;//MemUsage.swap_pss累加
};

MemUsage来源为vma

struct Vma {uint64_t start;uint64_t end;uint64_t offset;uint16_t flags;std::string name;uint64_t inode;bool is_shared;Vma() : start(0), end(0), offset(0), flags(0), name(""), inode(0), is_shared(false) {}Vma(uint64_t s, uint64_t e, uint64_t off, uint16_t f, const std::string& n,uint64_t iNode, bool is_shared): start(s), end(e), offset(off), flags(f), name(n), inode(iNode), is_shared(is_shared) {}~Vma() = default;void clear() { memset(&usage, 0, sizeof(usage)); }// Memory usage of this mapping.MemUsage usage;
};struct MemUsage {uint64_t vss;//"Size:"uint64_t rss;//"Rss:"uint64_t pss;//"Pss:"uint64_t uss;//"Private_Clean:"+"Private_Dirty:"uint64_t swap;//"Swap:"uint64_t swap_pss;//"SwapPss:"uint64_t private_clean;//"Private_Clean:"uint64_t private_dirty;//"Private_Dirty:"uint64_t shared_clean;//"Shared_Clean:"uint64_t shared_dirty;//"Shared_Dirty:"uint64_t anon_huge_pages;//"AnonHugePages:"uint64_t shmem_pmd_mapped;//"ShmemPmdMapped:"uint64_t file_pmd_mapped;//"FilePmdMapped:"uint64_t shared_hugetlb;//"Shared_Hugetlb:"uint64_t private_hugetlb;//"Private_Hugetlb:"uint64_t thp;MemUsage(): vss(0),rss(0),pss(0),uss(0),swap(0),swap_pss(0),private_clean(0),private_dirty(0),shared_clean(0),shared_dirty(0),anon_huge_pages(0),shmem_pmd_mapped(0),file_pmd_mapped(0),shared_hugetlb(0),private_hugetlb(0),thp(0) {}~MemUsage() = default;void clear() {vss = rss = pss = uss = swap = swap_pss = 0;private_clean = private_dirty = shared_clean = shared_dirty = 0;}
};

最终vma的对应关系

下标	name
HEAP_STACK	"[stack"、"[anon:stack_and_tls:"开头
HEAP_SO，is_swappable	".so"结尾
HEAP_JAR，is_swappable	".jar"结尾
HEAP_TTF，is_swappable	".apk"结尾
HEAP_TTF，is_swappable	".ttf"结尾
HEAP_DEX， sub_heap=HEAP_DEX_APP_DEX	".odex"结尾或（namesize>4&&".dex"）
HEAP_DEX， is_swappable	".vdex"结尾若"@boot"\|\|"/boot"\|\|"/apex"：sub_heap = HEAP_DEX_BOOT_VDEX 否则sub_heap = HEAP_DEX_APP_VDEX
HEAP_OAT，is_swappable	".oat"结尾
HEAP_ART，is_swappable	".art"、 ".art]"结尾若"@boot"\|\|"/boot"\|\|"/apex"：sub_heap = HEAP_ART_BOOT 否则sub_heap = HEAP_ART_APP
HEAP_UNKNOWN_DEV	"/dev/"开头
HEAP_GL_DEV	"/dev/kgsl-3d0"开头
HEAP_CURSOR	"/dev/ashmem/CursorWindow"开头
HEAP_DALVIK_OTHER sub_heap = HEAP_DALVIK_OTHER_ZYGOTE_CODE_CACHE	"/dev/ashmem/jit-zygote-cache"开头
HEAP_ASHMEM	"/dev/ashmem"开头
HEAP_DALVIK_OTHER sub_heap = HEAP_DALVIK_OTHER_APP_CODE_CACHE	"/memfd:jit-cache"开头
HEAP_DALVIK_OTHER sub_heap = HEAP_DALVIK_OTHER_ZYGOTE_CODE_CACHE	"/memfd:jit-zygote-cache"开头
HEAP_DALVIK_OTHER sub_heap=HEAP_DALVIK_OTHER_LINEARALLOC	"[anon:dalvik-LinearAlloc"开头
HEAP_DALVIK sub_heap = HEAP_DALVIK_NORMAL	"[anon:dalvik-alloc space"\|\|"[anon:dalvik-main space"开头
HEAP_DALVIK sub_heap = HEAP_DALVIK_LARGE	"[anon:dalvik-large object space"\|\|"[anon:dalvik-free list large object space"开头
HEAP_DALVIK sub_heap = HEAP_DALVIK_NON_MOVING	"[anon:dalvik-non moving space"开头
HEAP_DALVIK sub_heap = HEAP_DALVIK_ZYGOTE	"[anon:dalvik-zygote space"开头
HEAP_DALVIK_OTHER sub_heap = HEAP_DALVIK_OTHER_INDIRECT_REFERENCE_TABLE	"[anon:dalvik-indirect ref"开头
HEAP_DALVIK_OTHER sub_heap = HEAP_DALVIK_OTHER_APP_CODE_CACHE	"[anon:dalvik-jit-code-cache"\|\| "[anon:dalvik-data-code-cache"开头
HEAP_DALVIK_OTHER sub_heap = HEAP_DALVIK_OTHER_COMPILER_METADATA	"[anon:dalvik-CompilerMetadata"开头
HEAP_DALVIK_OTHER	"[anon:dalvik-"开头
HEAP_UNKNOWN sub_heap = HEAP_DALVIK_OTHER_ACCOUNTING	"[anon:"开头
HEAP_UNKNOWN_MAP 16	上面的都没有提到，但名字长度大于0的
HEAP_SO 9	本行的start==上一个map的end并且上一个是so

六、总结

数据来源整理：

输出标签	二级标签	含义	计算方式
Total RAM:		当前系统的所有内存大小。一般并不等于机器的物理内存大小。物理内存 - kernel reserved = 系统实际内存总和	/proc/meminfo的"MemTotal:"
Free RAM:	1+2+3
	1.cached pss	Cached 的是 OOM 900 以上的，一般都是切到后台的进程，表示可以随时回收	Total PSS by OOM adjustment中子模块为 cached 的合计值
	2.cached kernel		/proc/meminfo中的“Buffers:”+“Cached:”+“KReclaimable:” 如果“KReclaimable:”项为0则用"SReclaimable"
	3.free		/proc/meminfo中的"MemFree:”
DMA-BUF:			将/sys/kernel/dmabuf/buffers路径下每个目录下的size累加
	1.mapped		遍历每个/proc/$pid/proc/$pid/maps文件对于一个maps文件，遍历其每一行，将行尾有name的行的endaddr（第二串数字）和startaddr（第一串数字）相减作为size进行累加得到一个maps文件的mappedsize 最后将所有pid的mapedsize/1024进行累加
	2.unmapped		DMA-BUF total - mapped部分
DMA-BUF Heaps:			根据/dev/dma_heap路径下的文件名，遍历累加/sys/kernel/dmabuf/buffers/$@/exporter_name中的值与之对应的size之和
DMA-BUF Heaps pool:			/sys/kernel/dma_heap/total_pools_kb
GPU:			/sys/fs/bpf/map_gpu_mem_gpu_mem_total_map
	dmabuf		Total gpu - private
	private		memtrack_proc_get获取的 GPU-private (GL)内存的全局累计（Memtrack hal 定义PID 0为GL内存）
Used RAM:
	used pss		(所有/proc/$pid/maps中pss+swappss) - (OOM分类下cachedPss) - (category分类下的EGL和GL )+ (DMA-BUF的mapped部分)
	kernel(usedkernel)	kernelUsed	"Shmem:"+"SUnreclaim:"+"VmallocUsed:"+"PageTables:"+DMA中unmap部分+GPU中private部分其实还会加上!Debug.isVmapStack()?"KernelStack:":0，但除了初始化第一次调用之外，该值都为0
Lost RAM:			"Total RAM: "-（/proc/$@pid/smaps文件中纯Pss数据累加） -Free RAM的free部分- ("Buffers:"+("KReclaimable:"==0?"SReclaimable:":"KReclaimable:")+"Cached:"-"Mapped:")- Used RAM的kernel部分 - ZRAM的physical used部分
ZRAM:	physical used		/sys/block/zram$/mm_stat文件的第三列数字，如果mm_stat不存在则读取mem_used_total的值
	in swap		"SwapTotal:"-"SwapFree:"
	total swap		"SwapTotal:"
Tuning:			通过SystemProperties.get("dalvik.vm.heapgrowthlimit", "")获得单个应用可用最大内存的android属性。底层调用property.get
	(large		SystemProperties.get("dalvik.vm.heapsize", "16m") 表示单个进程可用的最大内存，但如果存在heapgrowthlimit参数，则以heapgrowthlimit为准.heapsize表示不受控情况下的极限堆，表示单个虚拟机或单个进程可用的最大内存。而android上的应用是带有独立虚拟机的，也就是每开一个应用就会打开一个独立的虚拟机（这样设计就会在单个程序崩溃的情况下不会导致整个系统的崩溃）。
	), oom=		ProcessList.CACHED_APP_MAX_ADJ(999)与mOomAdj（0,100,200,250,900,950）数组中挨个比较，mOomMinFree[index]值，否则返回mOomMinFree[mOomAdj.length-1]的值
	restore limit		$oom/3
	ActivityManager.isLowRamDeviceStatic()?		" (low-ram)" RAM小于1GB
	ActivityManager.isHighEndGfx()		" (high-end-gfx)" 内存大于1GB并且满足一些条件（在代码中写死了是满足的）

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