Why is Android 4.0 / Ice Cream Sandwich allocating so much heap memory?

Question

I noticed that on my Galaxy Nexus that android.content.res.Resources is allocating about 11MB. I discovered this as I was in the process of profiling things using

Answer 1

Pre-Honeycomb (<3.0), Bitmaps were allocated in native heap and did not appear in Dalvik heap dumps as shown by Eclipse MAT, etc. This native allocation still contributed towards maximum Dalvik heap limits for an application, and still caused garbage collection to run at approximately the correct time when approaching a low memory situation. This usage can be measured with Debug.getNativeHeapAllocatedSize().

Since Android 3.0 (including ICS), it now allocates the pixel data for Bitmaps in normal byte arrays in Dalvik heap. The practical effects of this are better/simplified garbage collection behaviour for Bitmaps (since they can be treated in a more orthodox way) and the ability to track Bitmap allocations in Dalvik heap dumps.

I do not think the actual memory usage for a particular application is significantly different between pre-Honeycomb and more recent releases, and that this is just a matter of an alternative accounting practice.

Memory Analysis for Android

BitMaps in Android