In my branch https://github.com/meta-introspector/agave-solana-validator edaa590 master you will find changes to drastically reduce the size of your test validator. The system allocates a huge amount of ram which i dont want it to.

Here are my changes to rpc/src/rpc_pubsub_service.rs

pub const MAX_ACTIVE_SUBSCRIPTIONS: usize = 126;
pub const DEFAULT_QUEUE_CAPACITY_ITEMS: usize = 1000;
pub const DEFAULT_TEST_QUEUE_CAPACITY_ITEMS: usize = 5;
pub const DEFAULT_QUEUE_CAPACITY_BYTES: usize = 16 * 1024 * 1024;

I hope this help anyone.