title: iOS Memory - VM: CG Image and IO Surface
body: <p>I'm trying to find out if my app is managing memory correctly, and I see 2 things in <code>profiler</code>, that I'm wondering about. I use a lot of images loaded from <code>PHAsset's</code>. When I minimize the app all these images are deinitialized. But I still see a lot of memory taken by: <code>VM: CG Image</code> and <code>VM: IO Surface</code> - few hundreds MB. I don't know what these are, and if they should be removed from the memory. Is this some kind of caching maybe? Should I be worried, that they stay in memory, or is this ok? Can I somehow force clearing these to test?</p>