Thank you for the clarification. I was trying to get the queue and traffic class information from where the packet is going to be dequeued. Its resolved now.
Regards Avinash On Fri, Feb 28, 2020 at 7:09 PM Singh, Jasvinder <jasvinder.si...@intel.com> wrote: > > > > -----Original Message----- > > From: dev <dev-boun...@dpdk.org> On Behalf Of Avinash . > > Sent: Wednesday, February 26, 2020 10:46 AM > > To: dev@dpdk.org > > Cc: Gokul Bargaje <gokulbargaje.182...@nitk.edu.in>; Mohit P. Tahiliani > > <tahili...@nitk.edu.in> > > Subject: [dpdk-dev] DPDK Enqueue Pipeline > > > > Hi all, > > The DPDK QoS scheduler has a 4-stage pipeline for enqueuing the packets. > > This is used for hiding the latency of prefetching the data structures. > > Why is there no pipeline for dequeuing the packets? > > The dequeue operation happens in stages that involves scanning bitmap > (that contains the active pipes info), followed by extracting information > about TC and queue of the pipe that will be considered for scheduling. As a > result, the information about pipe TC and queue become > available but not exposed to the application as this is internal to > dequeue operation. > > > How does the dequeue function maintain the state of a packet? In other > > words, if I want to backtrace the packet that is dequeued to get the > info of > > what was the traffic class and from which queue the packet was dequeued. > > Is there any way to get this. > > > The QoS dequeue operation is built around multiple grinders (packet > crunching engines) that works on different pipes at a time. Each grinder > follows the state machine (please have a look at the documentation) which > contains multiple stages starting from pipe bitmap scanning, tc and queue > detection, fetching the packet from the queue based on the available > credits, etc, all this information is kept in internal data structure of > the scheduler, and that info can be used to understand the flow or debug > the code. why you want to expose that intermediate info through public API > during execution? > > > > Regards > > > > -- > > Avinash >
