From: Vinicius Costa Gomes <vinicius.gomes@intel.com>
To: PO LIU <po.liu@nxp.com>,
"netdev\@vger.kernel.org" <netdev@vger.kernel.org>,
"linux-kernel\@vger.kernel.org" <linux-kernel@vger.kernel.org>
Cc: "davem\@davemloft.net" <davem@davemloft.net>,
"haustad\@cisco.com" <haustad@cisco.com>,
"nicolas.ferre\@microchip.com" <nicolas.ferre@microchip.com>,
"gregkh\@linuxfoundation.org" <gregkh@linuxfoundation.org>,
Mingkai Hu <mingkai.hu@nxp.com>, Roy Zang <roy.zang@nxp.com>,
PO LIU <po.liu@nxp.com>, PO LIU <po.liu@nxp.com>
Subject: Re: [PATCH] net: tsn: add an netlink interface between kernel and application layer
Date: Fri, 28 Dec 2018 11:29:56 -0800 [thread overview]
Message-ID: <87r2e14fgr.fsf@intel.com> (raw)
In-Reply-To: <1545968945-7290-1-git-send-email-Po.Liu@nxp.com>
Hi,
PO LIU <po.liu@nxp.com> writes:
> This patch provids netlink method to configure the TSN protocols hardwares.
> TSN guaranteed packet transport with bounded low latency, low packet delay
> variation, and low packet loss by hardware and software methods.
I don't think having another way to configure TSN features is a good
idea. We already have the CBS/ETF/taprio family of qdiscs, that provide
(or will in the near future, more on this later) a way to configure the
hardware.
A little background on the choice of qdiscs as an interface (and why we
came to believe they are a good abstraction), they already provide a way
to map packets into traffic classes (it isn't clear in our proposal how
you do that, but I think you are using something like mqprio), they
provide a neat way to "compose" (by installing one under another), they
already have a user facing API with various counters, and very
importantly for TSN they have mecanisms to offload some of their work to
the hardware.
I suggest is for you to take a look at how CBS offloading was
implemented for the Intel i210:
https://patchwork.ozlabs.org/cover/824626/
Patches 4 and 5 should be the interesting ones. I think you can use them
as inspiration for enabling CBS offload in your driver.
If you did take a look at those patches (and the current work that has
been upstreamed), my question then becomes, what are the reasons that it
might not work for your use cases?
>
> The three basic components of TSN are:
>
> 1. Time synchronization: This was implement by 8021AS which base on the
> IEEE1588 precision Time Protocol. This is configured by the other way
> in kernel.
> 8021AS not included in this patch.
>
> 2. Scheduling and traffic shaping and per-stream filter policing:
> This patch support Qbv/Qci.
I am working on a proposal for the API for Qbv (and Qbu) offloading
using taprio. I should send it soon-ish. Your feedback would be very
welcome.
Also, how to expose in the qdiscs the per-stream filtering and policing
parts (Qci) is something that I don't know how to do right now, any
suggestions would be nice.
In short, take a look at what's there and see what's missing for the
stuff that you care about, then we can work on that.
>
> 3. Selection of communication paths:
> This patch not support the pure software only TSN protocols(like Qcc)
> but hardware related configuration.
>
> TSN Protocols supports by this patch: Qbv/Qci/Qbu/Credit-base Shaper(Qav).
> This patch verified on NXP ls1028ardb board.
>
> Will add more protocols in the future.
>
> Signed-off-by: Po Liu <Po.Liu@nxp.com>
Cheers,
--
Vinicius
next prev parent reply other threads:[~2018-12-28 19:29 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1545968772-7237-1-git-send-email-Po.Liu@nxp.com>
2018-12-28 3:49 ` [PATCH] net: tsn: add an netlink interface between kernel and application layer PO LIU
2018-12-28 19:29 ` Vinicius Costa Gomes [this message]
2018-12-29 1:59 ` PO LIU
2019-01-02 19:01 ` Vinicius Costa Gomes
2019-01-03 3:10 ` Po Liu
2019-01-03 9:16 ` Ilias Apalodimas
2019-01-03 10:09 ` Po Liu
2019-01-03 11:38 ` Ilias Apalodimas
2019-01-04 9:01 ` Po Liu
2019-01-04 9:19 ` Ilias Apalodimas
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=87r2e14fgr.fsf@intel.com \
--to=vinicius.gomes@intel.com \
--cc=davem@davemloft.net \
--cc=gregkh@linuxfoundation.org \
--cc=haustad@cisco.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingkai.hu@nxp.com \
--cc=netdev@vger.kernel.org \
--cc=nicolas.ferre@microchip.com \
--cc=po.liu@nxp.com \
--cc=roy.zang@nxp.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).