[Bloat] finally... winning on wired!

[Dave Taht]

On Mon, Jan 2, 2012 at 9:07 AM, Dave Taht <dave.taht at gmail.com> wrote:
> On Mon, Jan 2, 2012 at 6:22 AM, Eric Dumazet <eric.dumazet at gmail.com> wrote:

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

Yes, that patch brings SFQ at light workloads to being
indistinguishable from QFQ!

http://www.teklibre.com/~d/bloat/sfqnewvsqfq10iperfs.png

(if you stare at this image long enough you might see a pattern, but I don't)
(I certainly am seeing an afterimage, though)

>>A "nolimit" implementation could use a dynamic memory allocator
>> scheme, eventually consuming less memory on typical use :)

At what point could SFQ be considered a replacement for pfifo_fast? :)

I have not managed to crash QFQ yet with your other new patch. I will
run it overnight.

There are new versions (bql-14) of both the net-next kernel and cerowrt up at:

http://huchra.bufferbloat.net/~d/bql/
http://huchra.bufferbloat.net/~cero1/bql-smoketests/

incorporating your SFQ and QFQ patches.

About the only kernel problem I have left to check for is some issues with
routing /27 and /32 netmasks I had a few weeks back.

* (for our studio audience)

while I'm DELIGHTED to see SFQ be 4x less latent now...
It is important to remain cognizant of just how much better SFQ and QFQ
are vs a vs the default PFIFO_FAST, for latency under load.

In the 10 iperf case, *65* times better. The difference between 2 ms and 110ms
is quite perceptible by a human, and all sorts of important stuff - voice, dns,
new connections leap to the head of the queue with either qdisc.

So, to give a concrete example - a DNS lookup takes about 16ms on my system,
and a new connection to google takes about 55 ms - so with QFQ/SFQ
inside of the *delay
I formerly experienced* (under this load) - I get connected to web sites,
and fairly often - their entire web pages.

Also ssh 'feels' much better. Voice works much better.


-- 
Dave Täht
SKYPE: davetaht
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