No excuse. If the software cannot meet the standard's requirements, it is non-conformant, which means it cannot be called a standard credit-based shaper.
But... I have no objection if someone wants to try software-only. I'm just saying that it is a waste of time for me. > -----Original Message----- > From: David Miller [mailto:da...@davemloft.net] > Sent: Thursday, October 5, 2017 2:05 PM > To: Rodney Cummings <rodney.cummi...@ni.com> > Cc: levipear...@gmail.com; j...@resnulli.us; vinicius.go...@intel.com; > netdev@vger.kernel.org; intel-wired-...@lists.osuosl.org; > j...@mojatatu.com; xiyou.wangc...@gmail.com; andre.gue...@intel.com; > ivan.bri...@intel.com; jesus.sanchez-palen...@intel.com; > boon.leong....@intel.com; richardcoch...@gmail.com; hen...@austad.us > Subject: Re: [next-queue PATCH v4 3/4] net/sched: Introduce Credit Based > Shaper (CBS) qdisc > > From: Rodney Cummings <rodney.cummi...@ni.com> > Date: Thu, 5 Oct 2017 18:41:48 +0000 > > > The IEEE Std 802.1Q specs for credit-based shaper require precise > transmit decisions > > within a 125 microsecond window of time. > > > > Even with the Preempt RT patch or similar enhancements, that isn't very > practical > > as software-only. I doubt that software would conform to the standard's > > requirements. > > > > This is analogous to memory, or CPU. > > I feel like this is looking for an excuse to not have to at least try to > implement > the software version of CBS.
