diff --git a/nx2navi.ini.example b/nx2navi.ini.example
index 687b71be..efb182bb 100644
--- a/nx2navi.ini.example
+++ b/nx2navi.ini.example
@@ -1007,10 +1007,11 @@
 # fps or more with Link on the floor. Each pass slows the game for its few seconds. 0 is off.
 # floor_watch = 0
 # 1: with trace = perf, walks of the process's address space count its private and write-combined memory every 600
-# frames (the "mem: process" line) and where its committed memory lies every 3600 frames, and when the process's own
-# commit (without the video memory Windows charges to it) rose 1 GiB over the highest it was, at most once a minute
-# (the "commit census" lines). Each walk holds the address-space lock for 100-260 ms and delays the next frame by as
-# much, so they are off unless asked for: leave it off in a run whose smoothness is judged.
+# frames (the "mem: process" line; at every 3600th frame, and any other where the commit census walks, that walk
+# stands in for it) and where its committed memory lies every 3600 frames, and when the process's own commit (without
+# the video memory Windows charges to it) rose 1 GiB over the highest it was, at most once a minute (the "commit
+# census" lines). Each walk holds the address-space lock for 100-260 ms and delays the next frame by as much, so they
+# are off unless asked for: leave it off in a run whose smoothness is judged.
 # mem_census = 0
 # 1: with trace = perf, the process's handles counted by kind (events, sections, threads, files...) at the 600-frame
 # report when their number grew by 16 or more since the last count (the "mem: handles" line). It reads the system's
diff --git a/runtime/perf_census.h b/runtime/perf_census.h
index 1aac306e..ffe57ecb 100644
--- a/runtime/perf_census.h
+++ b/runtime/perf_census.h
@@ -1,8 +1,10 @@
 // The part of a frame that an address-space walk of NX2NAVI_MEM_CENSUS overlapped, charged to the census (perf.c
 // ft_frame). vk_memory.c census_main walks on a thread of its own, but the walk holds the process's address-space lock,
-// which the replaying thread's write-watch queries (vk_memory.c vk_mem_mirror_begin) and every page fault wait for: in
+// which the replaying thread's write-watch queries (vk_memory.c vk_mem_mirror_begin) and every page fault take too. In
 // a session of 2026-11-13, 63 of the 66 hitches the stutter map charged to the replay sat beside such a walk, with a
-// 20-34 ms write-watch query in them. So the time the frame overlapped the walk is taken out of the frame's replay part
+// 20-34 ms write-watch query in them; the presenting thread's 600-frame memory report (vk_memory.c vk_mem_census) ran
+// at the same frames, and that log cannot tell which of the two held them up. The charge assumes the walk did, which a
+// play-test with mem_census = 0 checks: the time the frame overlapped the walk is taken out of the frame's replay part
 // first, then out of its unattributed part, never more than the overlap and never so much that the census part grows
 // past the frame. Apart from perf.c so that tests/census_charge_check.py builds it alone.
 #pragma once