389a916769
I was seeing lots of stack traces of people hung for noticeable amounts of time when switching between activities. e.g. On of the common gmail stacks showing this pause was: android.os.StrictMode$StrictModeDiskWriteViolation: policy=391 violation=1 at android.os.StrictMode$AndroidBlockGuardPolicy.startHandlingViolationException(StrictMode.java:272) at android.os.StrictMode$AndroidBlockGuardPolicy.onWriteToDisk(StrictMode.java:243) at dalvik.system.BlockGuard$WrappedFileSystem.open(BlockGuard.java:238) at java.io.FileOutputStream.<init>(FileOutputStream.java:97) at java.io.FileOutputStream.<init>(FileOutputStream.java:69) at com.android.server.am.UsageStatsService.writeStatsFLOCK(UsageStatsService.java:424) at com.android.server.am.UsageStatsService.writeStatsToFile(UsageStatsService.java:398) at com.android.server.am.UsageStatsService.notePauseComponent(UsageStatsService.java:539) at com.android.server.am.ActivityManagerService.updateUsageStats(ActivityManagerService.java:1856) at com.android.server.am.ActivityStack.startPausingLocked(ActivityStack.java:667) at com.android.server.am.ActivityStack.finishActivityLocked(ActivityStack.java:2925) at com.android.server.am.ActivityStack.requestFinishActivityLocked(ActivityStack.java:2836) at com.android.server.am.ActivityManagerService.finishActivity(ActivityManagerService.java:2276) at android.app.ActivityManagerNative.onTransact(ActivityManagerNative.java:237) at com.android.server.am.ActivityManagerService.onTransact(ActivityManagerService.java:1415) at android.os.Binder.execTransact(Binder.java:320) at dalvik.system.NativeStart.run(Native Method) at android.app.ActivityManagerProxy.finishActivity(ActivityManagerNative.java:1454) at android.app.Activity.finish(Activity.java:3260) at android.app.Activity.onBackPressed(Activity.java:1929) at android.app.Activity.onKeyUp(Activity.java:1907) at android.view.KeyEvent.dispatch(KeyEvent.java:1088) at android.app.Activity.dispatchKeyEvent(Activity.java:2087) at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchKeyEvent(PhoneWindow.java:1661) at android.view.ViewRoot.deliverKeyEventToViewHierarchy(ViewRoot.java:2543) at android.view.ViewRoot.handleFinishedEvent(ViewRoot.java:2516) at android.view.ViewRoot.handleMessage(ViewRoot.java:1866) at android.os.Handler.dispatchMessage(Handler.java:99) at android.os.Looper.loop(Looper.java:123) at android.app.ActivityThread.main(ActivityThread.java:3609) at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:521) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) at dalvik.system.NativeStart.main(Native Method) Change-Id: Id49157bc635017292eaefddc5e22d73f5f4ab05e