Rate limit calls to AM.getMyMemoryState().
Apps do not need to call getMyMemoryState any more than 200 times per
second. Rate limit this API to 2 calls every 10ms which will allow
apps to keep getting updated info at a reasonable interval.
Flag: android.app.rate_limit_get_my_memory_state
Bug: 365182205
Test: atest ActivityManagerTest
Test: manually check logs for cache hits/misses
Change-Id: I0ab53c8f477dc5a82c812d1fe541491e04367cc9
diff --git a/core/java/android/app/ActivityManager.java b/core/java/android/app/ActivityManager.java
index b4fb480..7273e64 100644
--- a/core/java/android/app/ActivityManager.java
+++ b/core/java/android/app/ActivityManager.java
@@ -247,6 +247,14 @@
@GuardedBy("mMemoryInfoCache")
private static final MemoryInfo mRateLimitedMemInfo = new MemoryInfo();
+ /** Rate-Limiting cache that allows no more than 200 calls to the service per second. */
+ @GuardedBy("mMyMemoryStateCache")
+ private static final RateLimitingCache<RunningAppProcessInfo> mMyMemoryStateCache =
+ new RateLimitingCache<>(10, 2);
+ /** Used to store cached results for rate-limited calls to getMyMemoryState(). */
+ @GuardedBy("mMyMemoryStateCache")
+ private static final RunningAppProcessInfo mRateLimitedMemState = new RunningAppProcessInfo();
+
/**
* Query handler for mGetCurrentUserIdCache - returns a cached value of the current foreground
* user id if the backstage_power/android.app.cache_get_current_user_id flag is enabled.
@@ -4223,6 +4231,23 @@
lastActivityTime = source.readLong();
}
+ /**
+ * Note: only fields that are updated in ProcessList.fillInProcMemInfoLOSP() are copied.
+ * @hide
+ */
+ public void copyTo(RunningAppProcessInfo other) {
+ other.pid = pid;
+ other.uid = uid;
+ other.flags = flags;
+ other.lastTrimLevel = lastTrimLevel;
+ other.importance = importance;
+ other.lru = lru;
+ other.importanceReasonCode = importanceReasonCode;
+ other.processState = processState;
+ other.isFocused = isFocused;
+ other.lastActivityTime = lastActivityTime;
+ }
+
public static final @android.annotation.NonNull Creator<RunningAppProcessInfo> CREATOR =
new Creator<RunningAppProcessInfo>() {
public RunningAppProcessInfo createFromParcel(Parcel source) {
@@ -4854,7 +4879,21 @@
* {@link RunningAppProcessInfo#lru}, and
* {@link RunningAppProcessInfo#importanceReasonCode}.
*/
- static public void getMyMemoryState(RunningAppProcessInfo outState) {
+ public static void getMyMemoryState(RunningAppProcessInfo outState) {
+ if (Flags.rateLimitGetMyMemoryState()) {
+ synchronized (mMyMemoryStateCache) {
+ mMyMemoryStateCache.get(() -> {
+ getMyMemoryStateInternal(mRateLimitedMemState);
+ return mRateLimitedMemState;
+ });
+ mRateLimitedMemState.copyTo(outState);
+ }
+ } else {
+ getMyMemoryStateInternal(outState);
+ }
+ }
+
+ private static void getMyMemoryStateInternal(RunningAppProcessInfo outState) {
try {
getService().getMyMemoryState(outState);
} catch (RemoteException e) {
diff --git a/core/java/android/app/activity_manager.aconfig b/core/java/android/app/activity_manager.aconfig
index c0c81df..38bd576 100644
--- a/core/java/android/app/activity_manager.aconfig
+++ b/core/java/android/app/activity_manager.aconfig
@@ -136,3 +136,14 @@
purpose: PURPOSE_BUGFIX
}
}
+
+flag {
+ namespace: "backstage_power"
+ name: "rate_limit_get_my_memory_state"
+ description: "Rate limit calls to getMyMemoryState using a cache"
+ is_fixed_read_only: true
+ bug: "365182205"
+ metadata {
+ purpose: PURPOSE_BUGFIX
+ }
+}
diff --git a/services/core/java/com/android/server/am/ProcessList.java b/services/core/java/com/android/server/am/ProcessList.java
index 5b4e573..e54e430 100644
--- a/services/core/java/com/android/server/am/ProcessList.java
+++ b/services/core/java/com/android/server/am/ProcessList.java
@@ -4121,19 +4121,6 @@
return false;
}
- private static int procStateToImportance(int procState, int memAdj,
- ActivityManager.RunningAppProcessInfo currApp,
- int clientTargetSdk) {
- int imp = ActivityManager.RunningAppProcessInfo.procStateToImportanceForTargetSdk(
- procState, clientTargetSdk);
- if (imp == ActivityManager.RunningAppProcessInfo.IMPORTANCE_BACKGROUND) {
- currApp.lru = memAdj;
- } else {
- currApp.lru = 0;
- }
- return imp;
- }
-
@GuardedBy(anyOf = {"mService", "mProcLock"})
void fillInProcMemInfoLOSP(ProcessRecord app,
ActivityManager.RunningAppProcessInfo outInfo,
@@ -4151,14 +4138,20 @@
}
outInfo.lastTrimLevel = app.mProfile.getTrimMemoryLevel();
final ProcessStateRecord state = app.mState;
- int adj = state.getCurAdj();
- int procState = state.getCurProcState();
- outInfo.importance = procStateToImportance(procState, adj, outInfo,
- clientTargetSdk);
+ final int procState = state.getCurProcState();
+ outInfo.importance = ActivityManager.RunningAppProcessInfo
+ .procStateToImportanceForTargetSdk(procState, clientTargetSdk);
+ if (outInfo.importance == ActivityManager.RunningAppProcessInfo.IMPORTANCE_BACKGROUND) {
+ outInfo.lru = state.getCurAdj();
+ } else {
+ outInfo.lru = 0;
+ }
outInfo.importanceReasonCode = state.getAdjTypeCode();
outInfo.processState = procState;
outInfo.isFocused = (app == mService.getTopApp());
outInfo.lastActivityTime = app.getLastActivityTime();
+ // Note: ActivityManager$RunningAppProcessInfo.copyTo() must be updated if what gets
+ // "filled into" outInfo in this method changes.
}
@GuardedBy(anyOf = {"mService", "mProcLock"})