Re: [Cerowrt-devel] fq_pie for linux

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

On Tue, Dec 11, 2018 at 10:32 AM Aaron Wood <woody77@gmail.com> wrote:
>
> On Wed, Dec 5, 2018 at 11:51 PM Toke Høiland-Jørgensen <toke@toke.dk> wrote:
>>
>> Dave Taht <dave.taht@gmail.com> writes:
>>
>> > https://github.com/gautamramk/FQ-PIE-for-Linux-Kernel/issues/2
>>
>> With all the variants of fq+AQM, maybe decoupling the FQ part and the
>> AQM part would be worthwhile, instead of reimplementing it for each
>> variant...
>
>
> That's a great idea, Toke.  There are a lot of places where I think it could work well, especially if it took a pluggable hash function for the hashing (at which point it's very general-purpose, and works on all sorts of different kinds of packets and workloads).  That would let it be used for userspace VPN links (as an example), or within QUIC (or similar), where the kernel can't see the embedded flows that are hidden by the TLS encryption.
>
> And having it pluggable in the kernel would also allow IPSec to work without bloat (last I checked it was horribly bufferbloated, but that was ~5 years ago).

ipsec terminating on the router was made to work beautifully with
fq_codel with this commit, below.

Before:

http://www.taht.net/~d/ipsec_fq_codel/oldqos.png

After:

http://www.taht.net/~d/ipsec_fq_codel/newqos.png

It's why we keep hoping to do the same thing to wireguard.

commit 264b87fa617e758966108db48db220571ff3d60e
Author: Andrew Collins <acollins@cradlepoint.com>
Date:   Wed Jan 18 14:04:28 2017 -0700

    fq_codel: Avoid regenerating skb flow hash unless necessary

    The fq_codel qdisc currently always regenerates the skb flow hash.
    This wastes some cycles and prevents flow seperation in cases where
    the traffic has been encrypted and can no longer be understood by the
    flow dissector.

    Change it to use the prexisting flow hash if one exists, and only
    regenerate if necessary.




-- 

Dave Täht
CTO, TekLibre, LLC
http://www.teklibre.com
Tel: 1-831-205-9740