Fix issue #17948288: Improve accuracy of memory use reporting

We now use Mapped to not double-count cached pages that are
mapped in to app processes.  Also read in some more values that
count towards kernel RAM use, and count buffers as free rather
than used RAM.

It also looks like the zram accounting is broken -- it was never
collecting the total zram reserved space.  I need to figure out
how I was finding that before.

Change-Id: I883f6fc93966774b5c7d2801d1801666dd11ed41

4 files changed, 72 insertions, 27 deletions

diff --git a/core/java/android/os/Debug.java b/core/java/android/os/Debug.java
index 18730b65a7dd..084ca30e263c 100644
--- a/core/java/android/os/Debug.java
+++ b/core/java/android/os/Debug.java
@@ -1093,7 +1093,15 @@ href="{@docRoot}guide/developing/tools/traceview.html">Traceview: A Graphical Lo
     /** @hide */
     public static final int MEMINFO_ZRAM_TOTAL = 8;
     /** @hide */
-    public static final int MEMINFO_COUNT = 9;
+    public static final int MEMINFO_MAPPED = 9;
+    /** @hide */
+    public static final int MEMINFO_VM_ALLOC_USED = 10;
+    /** @hide */
+    public static final int MEMINFO_PAGE_TABLES = 11;
+    /** @hide */
+    public static final int MEMINFO_KERNEL_STACK = 12;
+    /** @hide */
+    public static final int MEMINFO_COUNT = 13;
 
     /**
      * Retrieves /proc/meminfo.  outSizes is filled with fields
diff --git a/core/java/com/android/internal/util/MemInfoReader.java b/core/java/com/android/internal/util/MemInfoReader.java
index 5f240f73b5be..1dd946494d4d 100644
--- a/core/java/com/android/internal/util/MemInfoReader.java
+++ b/core/java/com/android/internal/util/MemInfoReader.java
@@ -34,40 +34,65 @@ public final class MemInfoReader {
         }
     }
 
+    /**
+     * Total amount of RAM available to the kernel.
+     */
     public long getTotalSize() {
         return mInfos[Debug.MEMINFO_TOTAL] * 1024;
     }
 
+    /**
+     * Amount of RAM that is not being used for anything.
+     */
     public long getFreeSize() {
         return mInfos[Debug.MEMINFO_FREE] * 1024;
     }
 
+    /**
+     * Amount of RAM that the kernel is being used for caches, not counting caches
+     * that are mapped in to processes.
+     */
     public long getCachedSize() {
-        return mInfos[Debug.MEMINFO_CACHED] * 1024;
+        return getCachedSizeKb() * 1024;
     }
 
+    /**
+     * Amount of RAM that is in use by the kernel for actual allocations.
+     */
+    public long getKernelUsedSize() {
+        return getKernelUsedSizeKb() * 1024;
+    }
+
+    /**
+     * Total amount of RAM available to the kernel.
+     */
     public long getTotalSizeKb() {
         return mInfos[Debug.MEMINFO_TOTAL];
     }
 
+    /**
+     * Amount of RAM that is not being used for anything.
+     */
     public long getFreeSizeKb() {
         return mInfos[Debug.MEMINFO_FREE];
     }
 
+    /**
+     * Amount of RAM that the kernel is being used for caches, not counting caches
+     * that are mapped in to processes.
+     */
     public long getCachedSizeKb() {
-        return mInfos[Debug.MEMINFO_CACHED];
-    }
-
-    public long getBuffersSizeKb() {
-        return mInfos[Debug.MEMINFO_BUFFERS];
-    }
-
-    public long getShmemSizeKb() {
-        return mInfos[Debug.MEMINFO_SHMEM];
+        return mInfos[Debug.MEMINFO_BUFFERS]
+                + mInfos[Debug.MEMINFO_CACHED] - mInfos[Debug.MEMINFO_MAPPED];
     }
 
-    public long getSlabSizeKb() {
-        return mInfos[Debug.MEMINFO_SLAB];
+    /**
+     * Amount of RAM that is in use by the kernel for actual allocations.
+     */
+    public long getKernelUsedSizeKb() {
+        return mInfos[Debug.MEMINFO_SHMEM] + mInfos[Debug.MEMINFO_SLAB]
+                + mInfos[Debug.MEMINFO_VM_ALLOC_USED] + mInfos[Debug.MEMINFO_PAGE_TABLES]
+                + mInfos[Debug.MEMINFO_KERNEL_STACK];
     }
 
     public long getSwapTotalSizeKb() {
diff --git a/core/jni/android_os_Debug.cpp b/core/jni/android_os_Debug.cpp
index 7b3528b23823..9ec9993a248c 100644
--- a/core/jni/android_os_Debug.cpp
+++ b/core/jni/android_os_Debug.cpp
@@ -552,6 +552,10 @@ enum {
     MEMINFO_SWAP_TOTAL,
     MEMINFO_SWAP_FREE,
     MEMINFO_ZRAM_TOTAL,
+    MEMINFO_MAPPED,
+    MEMINFO_VMALLOC_USED,
+    MEMINFO_PAGE_TABLES,
+    MEMINFO_KERNEL_STACK,
     MEMINFO_COUNT
 };
 
@@ -590,6 +594,11 @@ static void android_os_Debug_getMemInfo(JNIEnv *env, jobject clazz, jlongArray o
             "Slab:",
             "SwapTotal:",
             "SwapFree:",
+            "ZRam:",
+            "Mapped:",
+            "VmallocUsed:",
+            "PageTables:",
+            "KernelStack:",
             NULL
     };
     static const int tagsLen[] = {
@@ -601,12 +610,17 @@ static void android_os_Debug_getMemInfo(JNIEnv *env, jobject clazz, jlongArray o
             5,
             10,
             9,
+            5,
+            7,
+            12,
+            11,
+            12,
             0
     };
-    long mem[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0 };
+    long mem[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
 
     char* p = buffer;
-    while (*p && numFound < 8) {
+    while (*p && numFound < 13) {
         int i = 0;
         while (tags[i]) {
             if (strncmp(p, tags[i], tagsLen[i]) == 0) {
diff --git a/services/core/java/com/android/server/am/ActivityManagerService.java b/services/core/java/com/android/server/am/ActivityManagerService.java
index 8dfb3217c0af..970d275ac15a 100755
--- a/services/core/java/com/android/server/am/ActivityManagerService.java
+++ b/services/core/java/com/android/server/am/ActivityManagerService.java
@@ -1734,8 +1734,13 @@ public final class ActivityManagerService extends ActivityManagerNative
                         logBuilder.append("  MemInfo: ");
                         logBuilder.append(infos[Debug.MEMINFO_SLAB]).append(" kB slab, ");
                         logBuilder.append(infos[Debug.MEMINFO_SHMEM]).append(" kB shmem, ");
+                        logBuilder.append(infos[Debug.MEMINFO_VM_ALLOC_USED]).append(" kB vm alloc, ");
+                        logBuilder.append(infos[Debug.MEMINFO_PAGE_TABLES]).append(" kB page tables ");
+                        logBuilder.append(infos[Debug.MEMINFO_KERNEL_STACK]).append(" kB kernel stack\n");
+                        logBuilder.append("           ");
                         logBuilder.append(infos[Debug.MEMINFO_BUFFERS]).append(" kB buffers, ");
                         logBuilder.append(infos[Debug.MEMINFO_CACHED]).append(" kB cached, ");
+                        logBuilder.append(infos[Debug.MEMINFO_MAPPED]).append(" kB mapped, ");
                         logBuilder.append(infos[Debug.MEMINFO_FREE]).append(" kB free\n");
                         if (infos[Debug.MEMINFO_ZRAM_TOTAL] != 0) {
                             logBuilder.append("  ZRAM: ");
@@ -1952,9 +1957,7 @@ public final class ActivityManagerService extends ActivityManagerNative
                                 + (SystemClock.uptimeMillis()-start) + "ms");
                         mProcessStats.addSysMemUsageLocked(memInfo.getCachedSizeKb(),
                                 memInfo.getFreeSizeKb(), memInfo.getZramTotalSizeKb(),
-                                memInfo.getBuffersSizeKb()+memInfo.getShmemSizeKb()
-                                        +memInfo.getSlabSizeKb(),
-                                nativeTotalPss);
+                                memInfo.getKernelUsedSizeKb(), nativeTotalPss);
                     }
                 }
 
@@ -14240,8 +14243,7 @@ public final class ActivityManagerService extends ActivityManagerNative
                 synchronized (this) {
                     mProcessStats.addSysMemUsageLocked(memInfo.getCachedSizeKb(),
                             memInfo.getFreeSizeKb(), memInfo.getZramTotalSizeKb(),
-                            memInfo.getBuffersSizeKb()+memInfo.getShmemSizeKb()+memInfo.getSlabSizeKb(),
-                            nativeProcTotalPss);
+                            memInfo.getKernelUsedSizeKb(), nativeProcTotalPss);
                 }
             }
             if (!brief) {
@@ -14280,16 +14282,12 @@ public final class ActivityManagerService extends ActivityManagerNative
             }
             if (!isCompact) {
                 pw.print(" Used RAM: "); pw.print(totalPss - cachedPss
-                        + memInfo.getBuffersSizeKb() + memInfo.getShmemSizeKb()
-                        + memInfo.getSlabSizeKb()); pw.print(" kB (");
+                        + memInfo.getKernelUsedSizeKb()); pw.print(" kB (");
                         pw.print(totalPss - cachedPss); pw.print(" used pss + ");
-                        pw.print(memInfo.getBuffersSizeKb()); pw.print(" buffers + ");
-                        pw.print(memInfo.getShmemSizeKb()); pw.print(" shmem + ");
-                        pw.print(memInfo.getSlabSizeKb()); pw.println(" slab)");
+                        pw.print(memInfo.getKernelUsedSizeKb()); pw.print(" kernel)\n");
                 pw.print(" Lost RAM: "); pw.print(memInfo.getTotalSizeKb()
                         - totalPss - memInfo.getFreeSizeKb() - memInfo.getCachedSizeKb()
-                        - memInfo.getBuffersSizeKb() - memInfo.getShmemSizeKb()
-                        - memInfo.getSlabSizeKb()); pw.println(" kB");
+                        - memInfo.getKernelUsedSizeKb()); pw.println(" kB");
             }
             if (!brief) {
                 if (memInfo.getZramTotalSizeKb() != 0) {