Date: Fri, 5 Sep 2014 10:10:39 -0400
From: Bob Copeland <me@bobcopeland.com>
To: Dani Camps <danicamps81@gmail.com>
Cc: Johannes Berg <johannes@sipsolutions.net>,
	linux-wireless@vger.kernel.org
Subject: Re: wmediumd performance penalty
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On Fri, Sep 05, 2014 at 09:03:25AM -0400, Bob Copeland wrote:
> Indeed you can.
> 
> For what it's worth, although I can't speak for wmediumd at the moment,
> in the precursor to it that I wrote, I got about 25 Mbps achieved with
> a phy rate of 54 Mbps when simulating the physical layer, which I think
> is pretty close to real world overhead in non-agg case.  With plain old
> mac80211_hwsim you can get several Gbps.

Sort of - it relied on a different hwsim interface than what made it
upstream, and was for a one-off investigation, so it's mostly useless.
Code is here though:

http://bobcopeland.com/srcs/wifi_sim.tar.gz

Glancing at the wmediumd code again, it doesn't try to simulate airtime
either, just does some loss reporting.  Do you have a use-case which
needs the airtime simulation?

A while ago, I rewrote my PER computations in C instead of pre-generating
them from matlab into a huge lookup table (see per.c):

https://github.com/bcopeland/wmediumd/tree/add_per_model

So, I'd be interested in hooking that up and throwing a scheduler into
wmediumd to optionally simulate airtime.

-- 
Bob Copeland %% www.bobcopeland.com