Re: [Cerowrt-devel] Ubnt builds

[Dave Taht <dave.taht@gmail.com>]

I just pushed out those skb memory use reduction hacks. It would be
good if more were to try them, in std openwrt, and also a patch for
pfifo_fast produced, for openwrt's general use.

https://github.com/dtaht/Cerowrt-3.3/commit/d31d3faa0b7cf7254e6b657d85e8e5168ab55866

in some thread around here or the codel list was eric's proposed patch
reducing ath9k's skb pre-allocation size. I agree with eric in that
the current allocation method doesn't make any sense...

(and see comments in above commit)

Patch 53 was highly experimental and should be ignored. I have
something better now, but it ain't ready.

On Thu, Sep 6, 2012 at 9:20 AM, Dave Taht <dave.taht@gmail.com> wrote:
> The ubnt builds are a bit out of date (part of my test deployment of
> fq_codel at a campground here - the yurtlab!
> http://snapon.lab.bufferbloat.net/~d/lupin/yurtlab.jpg which is
> blessedly free
> of competing wifi signals)
>
> They are also a little specialized. Among other things, they have my
> ssh public key in them,
> and are keyed to local dns, they rely on the babel protocol to route
> and mesh together, although they do come up presently on a fixed ip
> address that needs to be changed, instead of relying on AHCP for their
> IPs and dns.
>
> All of quagga (including OSPF) IS built, it's just that babel is the default.
>
> In working with this build and test deployment I exposed some problems
> with memory usage in codel and the ath9k driver. Quagga will get
> OOM-killed under heavy loads, such as RTP and UDP flooding across
> multiple diffserv values, on the 2HP boxes in AP mode. The p2p
> backbone (nanostation M5s) has never crashed on me.
>
> This points long term towards developing a "mfq_codel", which would
> have one qdisc and *one* set of buffers that controls all four
> hardware queues. However, try as I might, I haven't wrapped my head
> around how to merge the code for sch_mq and sch_fq_codel, in a way
> that would work. (?)
>
> Aside from that it's working rather well, and the hacks I have in
> place now to reduce skb size seem to help a lot.
>
> Now that the memory problems are mostly beaten I will be doing a
> respin and re-deployment towards the end of the month. If I can build
> something a little more generic and easy to deploy on ubnt for others,
> I will do so, getting to where all this code runs well in 32MB is
> rather important to me.
>
> Let me know.
>
> On Thu, Sep 6, 2012 at 4:17 AM, Andy S <andys@bristolwireless.net> wrote:
>> I see that there are UBNT builds available for specific deployment
>> scenarios; we use Ubiquiti Bullet M5's on some parts of our (city-wide)
>> 5.8Ghz wireless network, but they don't support OSPF, so if any of the
>> builds of Cerowrt support Bullet M5 and OSPF (I see the Quagga-ospf  modules
>> available in the main devel builds) - we would be interested to hear/test!
>>
>> Cheers,
>>
>> A
>> --
>> http://www.bristolwireless.net/  | 0117 325 0067 |
>> sip:info@bristolwireless.net
>> Bristol Wireless
>> Windmill Hill City Farm
>> Philip Street
>> Bedminster
>> Bristol BS3 4EA
>>
>>
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>>
>
>
>
> --
> Dave Täht
> http://www.bufferbloat.net/projects/cerowrt/wiki - "3.3.8-17 is out
> with fq_codel!"



-- 
Dave Täht
http://www.bufferbloat.net/projects/cerowrt/wiki - "3.3.8-17 is out
with fq_codel!"