In Android 11, google introduced IORap, a new feature which greatly improves application startup times. They have observed that apps start more than 5% faster (cold startup) on average across a variety of devices. Some hero cases show 20%+ faster startup times. Users get this additional performance without any developer app changes!

IORap prefetching for Android apps

IORap reduces app startup times by predicting which I/O will be required and doing it ahead of time. Many app startups have a lot of time that the IO request queue isn’t being saturated because of blocking I/O. As a result, we aren’t maximizing IO latency. After prefetching the data and compacting the I/O, the app can access this data nearly instantly from the pagecache , significantly reducing app startup latency.

When they evaluated some popular top apps from the Play Store, 80%+ spent 10%+ time in blocking I/O during launch time. while ~50% of the apps even spent 20%+ time. A majority of apps they looked at could benefit from IORap.