On Fri, Nov 1, 2024 at 8:56 AM Jakub Kicinski <kuba@xxxxxxxxxx> wrote: > > On Fri, 1 Nov 2024 02:34:59 +0900 Taehee Yoo wrote: > > While I'm writing a patch I face an ambiguous problem here. > > ethnl_set_ring() first calls .get_ringparam() to get current config. > > Then it calls .set_ringparam() after it sets the current config + new > > config to param structures. > > The bnxt_set_ringparam() may receive ETHTOOL_TCP_DATA_SPLIT_ENABLED > > because two cases. > > 1. from user > > 2. from bnxt_get_ringparam() because of UNKNWON. > > The problem is that the bnxt_set_ringparam() can't distinguish them. > > The problem scenario is here. > > 1. tcp-data-split is UNKNOWN mode. > > 2. HDS is automatically enabled because one of LRO or GRO is enabled. > > 3. user changes ring parameter with following command > > `ethtool -G eth0 rx 1024` > > 4. ethnl_set_rings() calls .get_ringparam() to get current config. > > 5. bnxt_get_ringparam() returns ENABLE of HDS because of UNKNWON mode. > > 6. ethnl_set_rings() calls .set_ringparam() after setting param with > > configs comes from .get_ringparam(). > > 7. bnxt_set_ringparam() is passed ETHTOOL_TCP_DATA_SPLIT_ENABLED but > > the user didn't set it explicitly. > > 8. bnxt_set_ringparam() eventually force enables tcp-data-split. > > > > I couldn't find a way to distinguish them so far. > > I'm not sure if this is acceptable or not. > > Maybe we need to modify a scenario? > > I thought we discussed this, but I may be misremembering. > You may need to record in the core whether the setting came > from the user or not (similarly to IFF_RXFH_CONFIGURED). > User setting UNKNWON would mean "reset". > Maybe I'm misunderstanding.. Thanks a lot for that! I will try to add a new variable, that indicates tcp-data-split is set by user. It would be the tcp_data_split_mod in the kernel_ethtool_ringparam structure. Thanks a lot! Taehee Yoo
