WT Eviction seems to be less effective at queuing pages with updates than it is at queueing clean / dirty pages. We see that when the update threshold is reached, eviction does not do a good job of reducing the update threshold compared to when the clean trigger is reached.

We can test the performance of a change to have the eviction server prioritise evicting dirty and update pages when those triggers are reached, by clearing WT_EVICT_CACHE_CLEAN `evict_update_work` when either WT_EVICT_CACHE_DIRTY or WT_EIVCT_CACHE_UPDATE is set.