Currently, we tune eviction workers within __evict_tune_workers. There are several behaviours that the system currently takes that are worth further investigation.
Currently, it is possible for the evict tune to perform a "Forced re-evaluation" periodically, which can force the removal of eviction threads.
Additionally, following these re-evaluations we often see threads being added back into the eviction system quickly.
We should investigate these behaviours to try and streamline the adding/removal of eviction threads to avoid cases where we could potentially spend lots of resources creating and destroying threads while also impacting how available the system is for eviction.