On Fri, Aug 26, 2011 at 04:27:22PM -0700, Luis R. Rodriguez wrote:

I've just read this thread:

http://marc.info/?t=131277868500001&r=1&w=2

Since its not linux-wireless I'll chime in here. It seems that you are
trying to write an algorithm that will work for all networking and
802.11 devices. For networking is seems tough given driver
architecture and structure and the hope that all drivers will report
things in a fairly similar way. For 802.11 it was pointed out how we
have varying bandwidths and depending on the technology used for
connection (AP, 802.11s, IBSS) a different number of possible peers
need to be considered. 802.11 faced similar algorithmic complexities
with rate control and the way Andrew and Derek resolved this was to
not assume you could solve this problem and simply test out the water
by trial and error, that gave birth to the minstrel rate control
algorithm which Felix later rewrote for mac80211 with 802.11n support
[1]. Can the BQL algorithm make use of the same trial and error
mechanism and simply try different values and and use EWMA [2] to pick
the best size for the queue ?

[1] http://wireless.kernel.org/en/developers/Documentation/mac80211/RateControl/minstrel
[2] http://en.wikipedia.org/wiki/Moving_average#Exponential_moving_average

  Luis

Since Luis has stirred things up, I took the liberty of adding Tom's
BQL series to the debloat-testing tree:

	git://git.infradead.org/debloat-testing.git

I'm not sure how well BQL will interact with my eBDP-inspired hack,
debloat-testing commit d2566a176589775cb3a1de4fade972aa62d551ff
("mac80211: implement eBDP algorithm to fight bufferbloat").  So if
anyone wants to try enabling a wireless driver for BQL, you might
consider reverting that patch or at least testing without it.

<shameless plug>
And, of course, don't forget to come to the Bufferbloat and Networking
track at Linux Plumbers Conference next week in Santa Rosa, CA! :-)
</shameless plug>

John
-- 
John W. Linville		Someday the world will need a hero, and you
linville@tuxdriver.com			might be all we have.  Be ready.