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 | Fri, 13 Mar 2020 06:00:09 +0000 |
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Br, Po Liu
> -----Original Message----- > From: Vinicius Costa Gomes <vinicius.gomes@intel.com> > Sent: 2020年3月13日 7:35 > 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>; Murali Karicheri <m-karicheri2@ti.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 Liu <po.liu@nxp.com> writes: > > > 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: > > - 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?
I tested on www.nxp.com/LS1028A. There is nothing special for preemption.
> > And btw, thanks for the summary of the discussion.
> > > > > Thanks! > >> > >> > >> Cheers, > >> -- > >> Vinicius > > > -- > Vinicius
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