[Cerowrt-devel] Peeling GRO

Dave Taht dave.taht at gmail.com
Tue Apr 28 18:12:23 EDT 2015


On Tue, Apr 28, 2015 at 3:04 PM, Eric Dumazet <edumazet at google.com> wrote:
> This what we do in net/sched/sch_tbf.c  (search for tbf_segment())

Thank you! I had no idea that what I had been calling peeling already
existed. Perhaps in the simplest.qos model in the sqm-scripts (only
one sub qdisc) we should try tbf instead of htb?

> Although this is quite expensive, this is doable.

Turning off GRO universally is also expensive (in terms of costs to
other devices that are not rate limited, and in terms of actually
getting it right in the first place)

the mvneta dropped from 720Mbit each way to 320 with offloads off. We
have had similar trouble with the ubnt edgerouters (8 ports worth of
offloads).

We were mostly struggling with stuff
at very low rates < 60Mbit, now we are struggling with 100-300Mbit inbound....

>
>
>
> On Tue, Apr 28, 2015 at 2:38 PM, Dave Taht <dave.taht at gmail.com> wrote:
>>
>> Dear Eric:
>>
>> how would you go about peeling apart a TSO/GSO/GRO packet in a qdisc,
>> and then serving up one packet (or drr quantum's worth) of packets?
>>
>> I am seeing 64K GRO'd packets from mvneta driver in the linksys 1900ac
>> device in particular.
>>
>> ---------- Forwarded message ----------
>> From: Dave Taht <dave.taht at gmail.com>
>> Date: Tue, Apr 28, 2015 at 11:04 AM
>> Subject: documentation review request and out of tree cake builds for
>> openwrt/etc.
>> To: cake at lists.bufferbloat.net, bloat <bloat at lists.bufferbloat.net>,
>> "cerowrt-devel at lists.bufferbloat.net"
>> <cerowrt-devel at lists.bufferbloat.net>
>>
>>
>> 1) I have burned much of the morning updating this:
>>
>> http://www.bufferbloat.net/projects/codel/wiki/Cake
>>
>> Reviewers wanted.
>>
>> 2) I am not sure of the right configuration to push stuff to the
>> iproute2-cake repo (removing sfq_codel, and there is an important
>> bugfix in the mainline iproute2 that needs to be pushed into it)
>>
>> 3) I have pushed support for building cake out of tree in openwrt to
>> the ceropackages repo (for now), but have not created a new
>> iproute2-cake for it due to item 2. My intent would be to get both
>> into openwrt chaos calmer for further testing... in some repo or
>> another that wasn't ceropackages. the routing repo?
>>
>> 4) http://www.dslreports.com/forum/news,133536~fmode=flat~days=2000
>> has some good convo going on also.
>>
>> --
>> Dave Täht
>> Open Networking needs **Open Source Hardware**
>>
>> https://plus.google.com/u/0/+EricRaymond/posts/JqxCe2pFr67
>>
>>
>> --
>> Dave Täht
>> Open Networking needs **Open Source Hardware**
>>
>> https://plus.google.com/u/0/+EricRaymond/posts/JqxCe2pFr67
>
>



-- 
Dave Täht
Open Networking needs **Open Source Hardware**

https://plus.google.com/u/0/+EricRaymond/posts/JqxCe2pFr67



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