The default ABD chunk size is wasteful in common production workloads. This value should probably ultimately end up as a loader.conf value but in the interim can we reduce this value back to the originally submitted value of 1024?
As near as we could tell at work, the extent of the discussion of bumping the value from 1K to 4K was found here, but done so without any real world measurement: https://github.com/openzfs/openzfs/pull/326#issuecomment-291223116
A bugzilla issue has been opened up, too: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=222377