FairQ ALTQ for PF - Patch #2

[Matthew Dillon]

    After looking at WFQ (thanks to Max Laier for the reference!), and
    reading a few papers on it, I've got the second version of my fairq
    patch for ALTQ ready to go.

	fetch http://apollo.backplane.com/DFlyMisc/fairq02.patch

    This version removes the bitmap and the fixed array scan.  It keeps
    the fixed array of buckets but links the active buckets together into a
    circular queue.

    The 'hogs' option is now operational.  This option allows a bucket to
    drain in a burst (i.e. to not advance the round robin pointer) as long
    as its bandwidth is less then the specified bandwidth.

    My fair share scheduler is not yet weighted, but the new topology
    makes it possible to implement a full blown fair share scheduler
    (aka a weighted scheduler).  I haven't decided whether I want to go
    that far yet but in the mean I did implement a quick hack to
    insert new empty low-bandwidth queues (bw < hogs bw) at the head of
    the circular list instead of the tail (kind of a poor-man's deadline
    mechanic but not really).  I'm considering my options.  The new
    circular list gives me a lot of flexibility.

    Here is an example configuration.  Also note that your kernel must
    be compiled with the various ALTQ options, including the new
    ALTQ_FAIRQ option.


						-Matt


ports="{ 22, 25 }"
altq on vke0 fairq bandwidth 500Kb queue { normal, bulk }
queue bulk priority 1 bandwidth 100Kb \
	fairq(buckets 64, hogs 25Kb) qlimit 50
queue normal priority 2 bandwidth 400Kb \
	fairq(buckets 64, hogs 25Kb, default) qlimit 50

pass out on vke0 inet proto tcp from any to any \
	keep state queue normal
pass out on vke0 inet proto tcp from any to 216.240.41.28 port $ports \
	keep state queue bulk