On 04/20/2015 02:04 PM, Taras Kondratiuk wrote:
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?
Hi guys,
Is there any additional comments/objections on this patch?
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