.

wcfs/wcfs.go

@@ -332,11 +332,16 @@ package main
 //
 //    min(rev) in δFtail is min(@at) at which head/bigfile/file is currently watched (see below).
 //
-//    to support initial openings with @at being slightly in the past, we also
+//    To support initial openings with @at being slightly in the past, we also
 //    make sure that min(rev) is enough to cover last 1 minute of history
 //    from head/at.
 //
-//    See ΔFtail documentation in internal/zdata/δftail.go for more details.
+//    Scalability of δFtail plays important role in scalability of WCFS because
+//    δFtail, besides other places, is queried and potentially rebuilt at every
+//    FUSE read request (see 7 below).
+//
+//    See documentation in internal/zdata/δftail.go for more details on ΔFtail
+//    and its scalability properties.
 //
 // 7) when we receive a FUSE read(#blk) request to a head/bigfile/file, we process it as follows:
 //