I was told that it had something to do with balance_dirty_pages(), but how do I allow my system to dirty as much data as it wants to?

I'm running a world simulation with a lot of I/O churn, and I'm trying to get my system to

1. Let it dirty as much data as it wants to, even booting out anon or filecache to do so up to /proc/sys/vm/dirty_ratio

2. When it wants to writeback, don't throttle how much gets moved from Dirty to Writeback, but basically dump the entire load in one go and let the I/O scheduler digest it.