Does the DalvikVM Garbage Collector halt the whole VM?

Question

I have a situation in which an my Android application is not able to perform a soft real time task well in time as Garbage Collector is called which takes a few milliseconds

Answer 1

In Memory Management for Android Apps by Patrick Dubroy I found the following (slide 16, emphasis mine):

• Pre-Gingerbread GC:

  • Stop-the-world

  • Full heap collection

  • Pause times often > 100ms

• Gingerbread and beyond:

  • Concurrent (mostly)

  • Partial collections

  • Pause times usually < 5ms

In general, garbage collection must stop the whole VM, although nowadays this time greatly reduced. However neither VM nor Android platform as a whole are not real-time operating systems so don't expect such strict guarantees.

Why do you need single millisecond precision?