While investigating eviction changes in
WT-2453, one idea was to allow all eviction threads to populate the queue. I implemented a version of that at https://github.com/wiredtiger/wiredtiger/pull/2635. However, the performance was about half (running evict-btree.wtperf) what we see with the other changes in that branch.
We want to investigate why this approach is worse and where it is spending its time.