(1) Open imgur.com.
(2) Open the first image.
(3) Load the next image, wait until it is loaded, repeat ~40 times

Encountered problems:
1. map space becomes huge, due to fragmentation. The serializer constantly allocates huge junks and some maps seem to leak.
Proposed fix: do regular allocation in serializer (turn off the GC) and compact map space

2. tiny worker threads with too much memory overhead
Proposed fix: reduce page size

3. memory reducer not kicking in for the main thread resulting in high fragmentation
Proposed fix: tweak memory reducer heuristic to ensure compaction