Created a few separate issues to track performance improvements I've identified as part of looking into perf c2c data and the DcpProducer in general. (
MB-33151, MB-33153, MB-33157).
The fix for this regression did bring performance back to the old value, however by the time it was merged the "long pole" in the DcpProducer has shifted so the fix no longer improves performance. Will fix the other issues mentioned and see if performance improves to previous values.
MB-32389 is a bucket ticket for a general perf regression in kv_engine which may be of interest. Will resolve this issue as the regression has been fixed (the contentious cache line which was introduced is no longer present as of build 2202).