On Mon, May 11, 2015 at 05:29:39PM +0100, Bruce Richardson wrote: > Hi all, > > after a small amount of offline discussion with Marc Sune, here is an > alternative proposal for a higher-level interface - aka pktdev - to allow a > common Rx/Tx API across device types handling mbufs [for now, ethdev, ring > and KNI]. The key code is in the first patch fo the set - the second is an > example of a trivial usecase. > > What is different about this to previously: > * wrapper class, so no changes to any existing ring, ethdev implementations > * use of function pointers for RX/TX with an API that maps to ethdev > - this means there is little/no additional overhead for ethdev calls > - inline special case for rings, to accelerate that. Since we are at a > higher level, we can special case process some things if appropriate. This > means the impact to ring ops is one (predictable) branch per burst > * elimination of the queue abstraction. For the ring and KNI, there is no > concept of queues, so we just wrap the functions directly (no need even for > wrapper functions, the api's match so we can call directly). This also > means: > - adding in features per-queue, is far easier as we don't need to worry > about > having arrays of multiple queues. For example: > - adding in buffering on TX (or RX) is easier since again we only have a > single queue. > * thread safety is made easier using a wrapper. For a MP ring, we can create > multiple pktdevs around it, and each thread will then be able to use their > own copy, with their own buffering etc. > > However, at this point, I'm just looking for general feedback on this as an > approach. I think it's quite flexible - even more so than the earlier proposal > we had. It's less proscriptive and doesn't make any demands on any other libs. > > Comments/thoughts welcome. > > Bruce Richardson (2): > Add example pktdev implementation > example app showing pktdevs used in a chain >
Any comments on this RFC before I see about investing further time in it to clean it up a bit and submit as a non-RFC patchset for merge in 2.1? /Bruce
