mdb multilist walker should be a layered walker
Review Request #2508 — Created Jan. 31, 2020 and submitted
The mdb multilist walker should use mdb_layered_walk
::walk multilistagainst one of the
ARC_mru, both with and without the change and compared the output (was identical).
No -- a rather subtle bit of behavior with mdb_warn is that if the first argument (it's a printf() style function) doesn't end with a newline, it does the mdb equivalent of
printf(" : %s\n", strerror(errno))to append an error string. However if a newline is present, it doesn't do that.
In this instance, mdb_layered_walk should have set some sort of error value when it failed, so we'd want to set that (vs. the other uses in the function where that wouldn't be the case).