问题
I am looking to ensure my app does not consume too much memory on what are still fairly resource constrained devices. Several days ago I was using Instruments to determine how much memory my app was using and I was getting around 4-8 megabytes for Live Bytes. Today I run Instruments again and I am up around 30-35 megabytes for Live Bytes. I don't believe I have made any significant changes to my code between these two times.
My app uses an MKMapView with a custom tile overlay. I put off updating XCode for a fairly long time, and so I suspect that the difference may be that my iOS simulator was still using Google as opposed to Apple maps a few days ago, until I upgraded XCode.
As a small test, I created a new test app that just has an MKMapView, nothing else, and ran Instruments on it. It is common for the Live Bytes of this app to be on the order of 50-90 megabytes, even though it has no custom code whatsoever - I just drag n' dropped the MKMapView on.
Whether this is intentional on Apple's behalf for the new maps to use this much memory I do not know. Perhaps the map tiles are shared across apps and this is fine. Either way though, it complicates coming up with a reasonable approximation for how many Live Bytes I can safely use, given that most earlier suggestions are on the order of 5-20MB, and Apple's MKMapView consumes 50-90MB on its own.
Is there another useful metric I can go by failing Live Bytes being any use now?
Edit: looks like for others this is a legitimate memory management problem and causing app crashes: iOS6 MKMapView using a ton of memory, to the point of crashing the app, anyone else notice this?
来源：https://stackoverflow.com/questions/13340999/guide-to-acceptable-live-bytes-of-ios6-app-using-mkmapview