Fix the lost RAM calculation

The formula used when reporting memory usage when device goes
low on memory should exclude SwapPss, which was incorrectly
being included as part of totalPss.

BUG: 109762356
Test: Manually tested on a gobo device by making it
go low on memory. Verified that the Lost RAM in adb logcat
was negative before, and is positive with the change,
and close to Lost RAM from "dumpsys meminfo".

Change-Id: Ic54181b55fa03d3faebda4c0516c95c18ee39e41

2 files changed, 9 insertions, 3 deletions

diff --git a/services/core/java/com/android/server/am/ActivityManagerService.java b/services/core/java/com/android/server/am/ActivityManagerService.java
index 64e3c108dbf0..b1abbf1279a6 100644
--- a/services/core/java/com/android/server/am/ActivityManagerService.java
+++ b/services/core/java/com/android/server/am/ActivityManagerService.java
@@ -16023,6 +16023,7 @@ public class ActivityManagerService extends IActivityManager.Stub
         }
         updateCpuStatsNow();
         long[] memtrackTmp = new long[1];
+        long[] swaptrackTmp = new long[2];
         final List<ProcessCpuTracker.Stats> stats;
         // Get a list of Stats that have vsize > 0
         synchronized (mProcessCpuTracker) {
@@ -16033,12 +16034,13 @@ public class ActivityManagerService extends IActivityManager.Stub
         final int statsCount = stats.size();
         for (int i = 0; i < statsCount; i++) {
             ProcessCpuTracker.Stats st = stats.get(i);
-            long pss = Debug.getPss(st.pid, null, memtrackTmp);
+            long pss = Debug.getPss(st.pid, swaptrackTmp, memtrackTmp);
             if (pss > 0) {
                 if (infoMap.indexOfKey(st.pid) < 0) {
                     ProcessMemInfo mi = new ProcessMemInfo(st.name, st.pid,
                             ProcessList.NATIVE_ADJ, -1, "native", null);
                     mi.pss = pss;
+                    mi.swapPss = swaptrackTmp[1];
                     mi.memtrack = memtrackTmp[0];
                     memInfos.add(mi);
                 }
@@ -16046,14 +16048,17 @@ public class ActivityManagerService extends IActivityManager.Stub
         }
 
         long totalPss = 0;
+        long totalSwapPss = 0;
         long totalMemtrack = 0;
         for (int i=0, N=memInfos.size(); i<N; i++) {
             ProcessMemInfo mi = memInfos.get(i);
             if (mi.pss == 0) {
-                mi.pss = Debug.getPss(mi.pid, null, memtrackTmp);
+                mi.pss = Debug.getPss(mi.pid, swaptrackTmp, memtrackTmp);
+                mi.swapPss = swaptrackTmp[1];
                 mi.memtrack = memtrackTmp[0];
             }
             totalPss += mi.pss;
+            totalSwapPss += mi.swapPss;
             totalMemtrack += mi.memtrack;
         }
         Collections.sort(memInfos, new Comparator<ProcessMemInfo>() {
@@ -16215,7 +16220,7 @@ public class ActivityManagerService extends IActivityManager.Stub
         memInfoBuilder.append("\n");
         memInfoBuilder.append("  Lost RAM: ");
         memInfoBuilder.append(stringifyKBSize(memInfo.getTotalSizeKb()
-                - totalPss - memInfo.getFreeSizeKb() - memInfo.getCachedSizeKb()
+                - (totalPss - totalSwapPss) - memInfo.getFreeSizeKb() - memInfo.getCachedSizeKb()
                 - memInfo.getKernelUsedSizeKb() - memInfo.getZramTotalSizeKb()));
         memInfoBuilder.append("\n");
         Slog.i(TAG, "Low on memory:");
diff --git a/services/core/java/com/android/server/am/ProcessMemInfo.java b/services/core/java/com/android/server/am/ProcessMemInfo.java
index 83d29e2bba68..6c10a2af9fe6 100644
--- a/services/core/java/com/android/server/am/ProcessMemInfo.java
+++ b/services/core/java/com/android/server/am/ProcessMemInfo.java
@@ -24,6 +24,7 @@ public class ProcessMemInfo {
     final String adjType;
     final String adjReason;
     long pss;
+    long swapPss;
     long memtrack;
 
     public ProcessMemInfo(String _name, int _pid, int _oomAdj, int _procState,