On 12/14/2023 2:18 PM, Ferruh Yigit wrote: > > On 12/14/2023 10:58 AM, Michael Baum wrote: > > Add support for a new item type "RTE_FLOW_ITEM_TYPE_RANDOM". > > This item enables to match on some random value as a part of flow rule. > >
... > > > > +Item: ``RANDOM`` > > +^^^^^^^^^^^^^^^^ > > + > > +Matches a random value. > > + > > +A random unsigned integer (at most 32-bit) is generated for each > > +packet during flow rule processing, by either HW, SW or some external > > source. > > +Application can match on either exact value or range of values. > > +This value is not based on the packet data/headers. > > +Application shouldn't assume that this value is kept during the > > +lifetime of the packet. > > + > > +- ``value``: Specific value to match. > > + > > > Hi Michael, > > What is the usecase for the 'random' flow item? I can think about 2 different use cases: 1. Sampling - when application wants to sample certain percentage of the flow, it can match random value for getting it. 2. Distribution - when application wants to distribute the traffic between ports/queues, it can match all random value range with send to port/queue actions. > > Is it to match some kind of metadata generated by HW? It can be generated by either HW, SW or some external source. Each PMD supporting random item responds to have a generator for that. > Or is it a way to sampling traffic? It can be both. The PMD can use random value generated by HW while user match on it for sampling traffic. > > And how random 'random' item is, is it configured/set in HW or random per > packet? From API perspective, it is pure random not packet oriented. Same packet can get different values during the pipeline. I mentioned it in documentation: "This value is not based on the packet data/headers. Application shouldn't assume that this value is kept during the lifetime of the packet."
