Messages in this thread | | | From | Po Liu <> | Subject | RE: [EXT] Re: [v1,net-next, 1/2] ethtool: add setting frame preemption of traffic classes | Date | Wed, 26 Feb 2020 02:01:14 +0000 |
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Br, Po Liu
> -----Original Message----- > From: Murali Karicheri <m-karicheri2@ti.com> > Sent: 2020年2月26日 1:59 > To: Po Liu <po.liu@nxp.com>; Vinicius Costa Gomes > <vinicius.gomes@intel.com>; davem@davemloft.net; > hauke.mehrtens@intel.com; gregkh@linuxfoundation.org; > allison@lohutok.net; tglx@linutronix.de; hkallweit1@gmail.com; > saeedm@mellanox.com; andrew@lunn.ch; f.fainelli@gmail.com; > alexandru.ardelean@analog.com; jiri@mellanox.com; ayal@mellanox.com; > pablo@netfilter.org; linux-kernel@vger.kernel.org; netdev@vger.kernel.org > Cc: simon.horman@netronome.com; Claudiu Manoil > <claudiu.manoil@nxp.com>; Vladimir Oltean <vladimir.oltean@nxp.com>; > Alexandru Marginean <alexandru.marginean@nxp.com>; Xiaoliang Yang > <xiaoliang.yang_1@nxp.com>; Roy Zang <roy.zang@nxp.com>; Mingkai Hu > <mingkai.hu@nxp.com>; Jerry Huang <jerry.huang@nxp.com>; Leo Li > <leoyang.li@nxp.com>; Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org> > Subject: Re: [EXT] Re: [v1,net-next, 1/2] ethtool: add setting frame > preemption of traffic classes > > Caution: EXT Email > > Hi Po, > > On 02/21/2020 10:26 PM, Po Liu wrote: > > Hi Vinicius, > > > > > > Br, > > Po Liu > > > >> -----Original Message----- > >> From: Vinicius Costa Gomes <vinicius.gomes@intel.com> > >> Sent: 2020年2月22日 5:44 > >> To: Po Liu <po.liu@nxp.com>; davem@davemloft.net; > >> hauke.mehrtens@intel.com; gregkh@linuxfoundation.org; > >> allison@lohutok.net; tglx@linutronix.de; hkallweit1@gmail.com; > >> saeedm@mellanox.com; andrew@lunn.ch; f.fainelli@gmail.com; > >> alexandru.ardelean@analog.com; jiri@mellanox.com; > ayal@mellanox.com; > >> pablo@netfilter.org; linux- kernel@vger.kernel.org; > >> netdev@vger.kernel.org > >> Cc: simon.horman@netronome.com; Claudiu Manoil > >> <claudiu.manoil@nxp.com>; Vladimir Oltean > <vladimir.oltean@nxp.com>; > >> Alexandru Marginean <alexandru.marginean@nxp.com>; Xiaoliang > Yang > >> <xiaoliang.yang_1@nxp.com>; Roy Zang <roy.zang@nxp.com>; Mingkai > Hu > >> <mingkai.hu@nxp.com>; Jerry Huang <jerry.huang@nxp.com>; Leo Li > >> <leoyang.li@nxp.com>; Po Liu <po.liu@nxp.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@nxp.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: > > It is Murali :) > > > - Add config the fragment size, hold advance, release advance and > > flags; > > - I believe hold advance, release advance values are read only > > > 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." > - Couldn't understand the above? Could you please explain a bit more > on what you meant here?
Oh, I copy the original suggestion by you and other here. Just for more evaluation for next version.
> > Murali > > 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. > > > > Thanks! > >> > >> > >> Cheers, > >> -- > >> Vinicius > > -- > Murali Karicheri > Texas Instruments
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