On 04/17/2015 11:55 PM, Rosenboim, Leonid wrote: > > Guys, > > There are several versions of the Classifier API document floating in Google > docs, here is one such copy: > > https://docs.google.com/document/d/14KMqNPIgd7InwGzdP2EaI9g_V3o0_wxpgp3N-nd-RBE/edit?usp=sharing > > Here is a different perspective on what PMR and COS mean, perhaps in terms > of an abstract hardware implementation: > > CoS is a meta-data field assigned to each packet as it traverses the > classifier pipe-line. > > A packet is assigned an initial CoS by the pktio port which received it. > > Then, the packet is compared multiple times against a set of rules, and as it > is common with TCAMs, each comparisons happens against all rules in parallel. > > Each rule has two values to match: 1. the current CoS meta-data field; and 2. > a certain packet header field (value with a mask). > If both these values match, the packet met-data CoS field is changed (Action > taken) with the destination CoS of the matching rule. > > It is assumed that up to one such rule has matched. > > If a rule has matched, CoS has changed, the process continues one more time. > > If NO MATCH occured, the classification process is finished, and the packet > is delivered in accordance to the current CoS (i.e. the last matching rule or > the pktio default CoS if the first rule match failed). > > According to CoS, the packet buffer pool and the destination queue are > selected, and the packet is ready for application processing. > > Here are some additional observations with regads to use of CoS values: > > Multiple pktio may assign the same CoS initially. (eaming many pktio to one > CoS) > > Multple rules can assign the same CoS as destination (action). (meaning > multuple PMR to one destination CoS). > > Regarding the source CoS of a PMR, I can not rule out a PMR that can match > multiple CoS values (that is creating a many-to-many src-CoS to PMR > relationship), but this scheme seems problematic for ease of use as well as > implementation, so I would recommend to assume that each PMR should only have > a single source CoS. > > Multiple PMRs may have the same source-CoS, but different header fields ot > value/mask (creating an OR combination of PMRs). > > I felt that I had to take this discussion ina completely different direction > to avoid infinite recursion ;-)
Thanks, Leo. This exactly matches my understanding. Could you please add Reviewed-by tag if you are ok with the patch? -- Taras Kondratiuk _______________________________________________ lng-odp mailing list lng-odp@lists.linaro.org https://lists.linaro.org/mailman/listinfo/lng-odp
