On Fri, 4 Sep 2015, Jesper Dangaard Brouer wrote: > Thus, I could achieve the same performance results by tuning SLUB as I > could with "slab_nomerge". Maybe the advantage from "slab_nomerge" was > just that I got my "own" per CPU structures, and this implicitly larger > per CPU memory for myself? Well if multiple slabs are merged then there is potential pressure on the per node locks if huge amounts of objects are concurrently retrieved from the per node partial lists by two different subsystems. So cache merging can increase contention and thereby reduce performance. What you did with tuning is to reduce that contention by increasing the per cpu pages that do not require locks. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
