From: Yossi Kuperman <yossiku@mellanox.com>
To: Eric Dumazet <eric.dumazet@gmail.com>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
Jamal Hadi Salim <jhs@mojatatu.com>,
Jiri Pirko <jiri@mellanox.com>
Cc: Rony Efraim <ronye@mellanox.com>
Subject: Re: [RFC] Packet pacing (offload) for flow-aggregates and forwarding use-cases
Date: Mon, 6 Apr 2020 23:26:03 +0300 [thread overview]
Message-ID: <a8510982-96a0-f8d5-b401-f4cce3d30c3c@mellanox.com> (raw)
In-Reply-To: <46bb3497-a3cf-84ce-d0b5-855ecedbac15@mellanox.com>
On 26/03/2020 16:42, Yossi Kuperman wrote:
> On 24/03/2020 21:26, Eric Dumazet wrote:
>> On 3/24/20 12:05 PM, Yossi Kuperman wrote:
>>> Hello,
>>>
>>>
>>>
>>> We would like to support a forwarding use-case in which flows are classified and paced
>>>
>>> according to the selected class. For example, a packet arrives at the ingress hook of interface
>>>
>>> eth0, performing a sequence of filters and being redirected to interface eth1. Pacing takes
>>>
>>> place at the egress qdisc of eth1.
>>>
>>>
>>>
>>> FQ queuing discipline is classless and cannot provide such functionality. Each flow is
>>>
>>> paced independently, and different pacing is only configurable via a socket-option—less
>>>
>>> suitable for forwarding use-case.
>>>
>>>
>>>
>>> It is worth noting that although this functionality might be implemented by stacking multiple
>>>
>>> queuing disciplines, it will be very difficult to offload to hardware.
>>>
>>>
>>>
>>> We propose introducing yet another classful qdisc, where the user can specify in advance the
>>>
>>> desired classes (i.e. pacing) and provide filters to classify flows accordingly. Similar to other
>>>
>>> qdiscs, if skb->priority is already set, we can skip the classification; useful for forwarding
>>>
>>> use-case, as the user can set the priority field in ingress. Works nicely with OVS/TC.
>>>
>>>
>>>
>>> Any thoughts please?
>>>
>> Why not using HTB for this typical use case ?
>
> As far as I understand HTB is meant for rate-limiting, is the implementation fine-grained enough to support pacing
>
> as well?
>
Hi Eric, I'm not sure if HTB also performs pacing (similarly to FQ), can you please comment on that?
prev parent reply other threads:[~2020-04-06 20:26 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <d3d764d5-8eb6-59f9-cd3b-815de0258dbc@mellanox.com>
2020-03-24 19:26 ` [RFC] Packet pacing (offload) for flow-aggregates and forwarding use-cases Eric Dumazet
2020-03-26 14:42 ` Yossi Kuperman
2020-04-06 20:26 ` Yossi Kuperman [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=a8510982-96a0-f8d5-b401-f4cce3d30c3c@mellanox.com \
--to=yossiku@mellanox.com \
--cc=eric.dumazet@gmail.com \
--cc=jhs@mojatatu.com \
--cc=jiri@mellanox.com \
--cc=netdev@vger.kernel.org \
--cc=ronye@mellanox.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).