-enabled, the sweep phase of the garbage collection is done piecemeal
-whenever the need arises, typically during nursery collections. Lazy
-sweeping is enabled by default.
+enabled, the sweeping of individual major heap blocks is done
+piecemeal whenever the need arises, typically during nursery
+collections. Lazy sweeping is enabled by default.
+.TP
+\fB(no-)concurrent-sweep\fR
+Enables or disables concurrent sweep for the Mark&Sweep collector. If
+enabled, the iteration of all major blocks to determine which ones can
+be freed and which ones have to be kept and swept, is done
+concurrently with the running program. Concurrent sweeping is enabled
+by default.