linux-kernel - RE: [EXT] Re: [v1,net-next, 1/2] ethtool: add setting frame preemption of traffic classes

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <87a74lgnad.fsf@linux.intel.com>
Date:   Thu, 12 Mar 2020 16:34:50 -0700
From:   Vinicius Costa Gomes <vinicius.gomes@...el.com>
To:     Po Liu <po.liu@....com>,
        "davem\@davemloft.net" <davem@...emloft.net>,
        "hauke.mehrtens\@intel.com" <hauke.mehrtens@...el.com>,
        "gregkh\@linuxfoundation.org" <gregkh@...uxfoundation.org>,
        "allison\@lohutok.net" <allison@...utok.net>,
        "tglx\@linutronix.de" <tglx@...utronix.de>,
        "hkallweit1\@gmail.com" <hkallweit1@...il.com>,
        "saeedm\@mellanox.com" <saeedm@...lanox.com>,
        "andrew\@lunn.ch" <andrew@...n.ch>,
        "f.fainelli\@gmail.com" <f.fainelli@...il.com>,
        "alexandru.ardelean\@analog.com" <alexandru.ardelean@...log.com>,
        "jiri\@mellanox.com" <jiri@...lanox.com>,
        "ayal\@mellanox.com" <ayal@...lanox.com>,
        "pablo\@netfilter.org" <pablo@...filter.org>,
        "linux-kernel\@vger.kernel.org" <linux-kernel@...r.kernel.org>,
        "netdev\@vger.kernel.org" <netdev@...r.kernel.org>
Cc:     "simon.horman\@netronome.com" <simon.horman@...ronome.com>,
        Claudiu Manoil <claudiu.manoil@....com>,
        Vladimir Oltean <vladimir.oltean@....com>,
        Alexandru Marginean <alexandru.marginean@....com>,
        Xiaoliang Yang <xiaoliang.yang_1@....com>,
        Roy Zang <roy.zang@....com>, Mingkai Hu <mingkai.hu@....com>,
        Jerry Huang <jerry.huang@....com>, Leo Li <leoyang.li@....com>,
        Murali Karicheri <m-karicheri2@...com>,
        Ivan Khoronzhuk <ivan.khoronzhuk@...aro.org>
Subject: RE: [EXT] Re: [v1,net-next, 1/2] ethtool: add setting frame preemption of traffic classes

Hi,

Po Liu <po.liu@....com> writes:

> Hi Vinicius,
>
>
> Br,
> Po Liu
>
>> -----Original Message-----
>> From: Vinicius Costa Gomes <vinicius.gomes@...el.com>
>> Sent: 2020年2月22日 5:44
>> To: Po Liu <po.liu@....com>; davem@...emloft.net;
>> hauke.mehrtens@...el.com; gregkh@...uxfoundation.org; allison@...utok.net;
>> tglx@...utronix.de; hkallweit1@...il.com; saeedm@...lanox.com;
>> andrew@...n.ch; f.fainelli@...il.com; alexandru.ardelean@...log.com;
>> jiri@...lanox.com; ayal@...lanox.com; pablo@...filter.org; linux-
>> kernel@...r.kernel.org; netdev@...r.kernel.org
>> Cc: simon.horman@...ronome.com; Claudiu Manoil
>> <claudiu.manoil@....com>; Vladimir Oltean <vladimir.oltean@....com>;
>> Alexandru Marginean <alexandru.marginean@....com>; Xiaoliang Yang
>> <xiaoliang.yang_1@....com>; Roy Zang <roy.zang@....com>; Mingkai Hu
>> <mingkai.hu@....com>; Jerry Huang <jerry.huang@....com>; Leo Li
>> <leoyang.li@....com>; Po Liu <po.liu@....com>
>> Subject: [EXT] Re: [v1,net-next, 1/2] ethtool: add setting frame preemption of
>> traffic classes
>> 
>> Caution: EXT Email
>> 
>> Hi,
>> 
>> Po Liu <po.liu@....com> writes:
>> 
>> > IEEE Std 802.1Qbu standard defined the frame preemption of port
>> > traffic classes. This patch introduce a method to set traffic classes
>> > preemption. Add a parameter 'preemption' in struct
>> > ethtool_link_settings. The value will be translated to a binary, each
>> > bit represent a traffic class. Bit "1" means preemptable traffic
>> > class. Bit "0" means express traffic class.  MSB represent high number
>> > traffic class.
>> >
>> > If hardware support the frame preemption, driver could set the
>> > ethernet device with hw_features and features with NETIF_F_PREEMPTION
>> > when initializing the port driver.
>> >
>> > User can check the feature 'tx-preemption' by command 'ethtool -k
>> > devname'. If hareware set preemption feature. The property would be a
>> > fixed value 'on' if hardware support the frame preemption.
>> > Feature would show a fixed value 'off' if hardware don't support the
>> > frame preemption.
>> >
>> > Command 'ethtool devname' and 'ethtool -s devname preemption N'
>> > would show/set which traffic classes are frame preemptable.
>> >
>> > Port driver would implement the frame preemption in the function
>> > get_link_ksettings() and set_link_ksettings() in the struct ethtool_ops.
>> >
>> 
>> Any updates on this series? If you think that there's something that I could help,
>> just tell.
>
> Sorry for the long time not involve the discussion. I am focus on other tsn code for tc flower.
> If you can take more about this preemption serial, that would be good.
>
> I summary some suggestions from Marali Karicheri and Ivan Khornonzhuk and by you and also others:
> - Add config the fragment size, hold advance, release advance and flags;
>     My comments about the fragment size is in the Qbu spec limit the fragment size " the minimum non-final fragment size is 64,
> 128, 192, or 256 octets " this setting would affect the guardband setting for Qbv. But the ethtool setting could not involve this issues but by the taprio side.
> - " Furthermore, this setting could be extend for a serial setting for mac and traffic class."  "Better not to using the traffic class concept."
>    Could adding a serial setting by "ethtool --preemption xxx" or other name. I don' t think it is good to involve in the queue control since queues number may bigger than the TC number.
> - The ethtool is the better choice to configure the preemption
>   I agree.

Just a quick update. I was able to dedicate some time to this, and have
something aproaching RFC-quality, but it needs more testing.

So, question, what were you using for testing this? Anything special?

And btw, thanks for the summary of the discussion.

>
> Thanks！
>> 
>> 
>> Cheers,
>> --
>> Vinicius


-- 
Vinicius