Hi Martin, first of all: thanks alot for your efforts (and sorry for a bit of silence from my side, I'm busy as usual ..) Martin A. Brown wrote: > Greetings Nickola! > > : Just a question - wasn't Mr. Kenjiro Cho [1] the original writer > : of the HFSC queueing discipline, following the work of Mr. Hui > : Zhang [2], et al.? > > <snip/> > > In fact, I was probably not quite exact enough in my introduction. > I meant this remark to be understood specifically with regard to the > Linux HFSC implementation. > > You are quite correct to allude to the *BSD altq HFSC implementation > which preceded Patrick McHardy's work. > > Thanks for the point of clarification, Nickola. Other history on > HFSC would probably need to be introduced by somebody who knows this > topic better than I do. The first implementation was written by Hui Zhang and his colleagues at Carnegie Mellon. It wasn't very pretty and IIRC not implemented in a very efficient way. Kenjiro Cho reimplemented it while he was at Carnegie Mellon, and incorporated his implementation into ALTQ. It was later enhanced by Oleg Cherevko, who added upper-limit curves for non-work-conserving mode. This is the implementation used in the various BSDs. The Linux version if a port of the ALTQ version, but includes a few enhancements like rbtrees instead of linked lists and a couple of O(n) algorithms replaced by O(1) variants, which increases scalability with many classes greatly. Hope that clears up this history :) _______________________________________________ LARTC mailing list LARTC@xxxxxxxxxxxxxxx http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc
