[Bloat] finally... winning on wired!

[Eric Dumazet]

Le lundi 02 janvier 2012 à 01:40 +0100, Dave Taht a écrit :

> SFQ has generally been quite good in many respects. SFQ also does
> improved hashing on net-next. But: QFQ seemed very promising also, and
> it took until now to see it clearly, with BQL turned on.
> 
> To look in more detail at sfq vs qfq, under even heavier load:
> 
> http://www.teklibre.com/~d/bloat/pfifo_sfq_vs_qfq_linear50.png
> 
> It's really very rare in my life that I've seen a win vs an existing
> system of these orders of magnitude. It's taken me a week to make sure
> the results were real, and repeatable... I thought about sitting on
> them for a while longer actually. I'd really like someone else to
> repeat these tests and tell me I'm not seeing things!
> 
> I have hopes QFQ will do even better at 10Mbit vs SFQ.

Happy New Year Dave

This makes no sense to me.

For most uses on a host or residential router, SFQ should perform the
same than QFQ.

QFQ is the thing you want to use on a big node, when SFQ limits are
reached (SFQ as implemented in linux : at most 127 concurrent flows, and
at most 127 packets in queue. This could be changed with an increase of
memory cost [ which are really small anyway : about 4 Kbytes per SFQ
queue ]. A "nolimit" implementation could use a dynamic memory allocator
schem, eventually consuming less memory on typical use :)

Please try the patch I posted this morning to solve this SFQ bug.

http://patchwork.ozlabs.org/patch/133793/