Dpaa order restoration

sedat_altun · ‎08-11-2019

My question is about Order restoration at DPAA1 architecture.

Some protocols like tcp requires the packets/ segmens in order. Out of order segments cause speed degregation. So I have to maintain the order of the packets/segments from ingress to egress . I am using T4240rdb and NXP sdk 2.0.

Order preservation within a flow by using fmc can be activated but this method can not use the cores efficiently because there is no pool channel. So I need that all the cores to handle the packets from the different flows but at engress I need them to be in order. Since the order restoration method use pool channels I want to activate this method on linux kernel at sdk 2.0.

In summary is it possible to use Qman order restoration with linux Sdk 2.0? Or do I have to use usdpaa to use order restoration .

I asked this question to nxp many times but couldnt get any satisfactory answer.

Any idea about this problem will be appreciated.

Best regards.

yipingwang · ‎08-12-2019

Hello Sedat Altun,

Order restoration is a feature of the QMan hardware that allows frame enqueue operations to be re-assembled in an ORP（Order Restoration Point). SDK 2.0 Linux doesn't implement this feature.

Frame queue descriptors can serve one or both of two complimentary purposes. A small subset of fields in the FQDs are used to implement an "Order Restoration Point", which allows an FQD to act as a reassembly window for out-of-sequence enqueues. FQDs also contain a sequence number field that generates increasing sequence numbers for all frames dequeued from the FQ. This dequeue activity sequence number is also called an "Order Definition Point". The idea is that frames dequeued from a given FQ (ODP) may get out-of-sequence during processing before they're enqueued onto an egress FQ, so the enqueue function allows one to not only specify the desination FQD, but also an ORP that the enqueue command should first pass through - which might hold up the intended enqueue until other, missing, sequence elements are enqueued.

Thanks,

Yiping

View solution in original post

yipingwang · ‎08-12-2019

Hello Sedat Altun,

Order restoration is a feature of the QMan hardware that allows frame enqueue operations to be re-assembled in an ORP（Order Restoration Point). SDK 2.0 Linux doesn't implement this feature.

Frame queue descriptors can serve one or both of two complimentary purposes. A small subset of fields in the FQDs are used to implement an "Order Restoration Point", which allows an FQD to act as a reassembly window for out-of-sequence enqueues. FQDs also contain a sequence number field that generates increasing sequence numbers for all frames dequeued from the FQ. This dequeue activity sequence number is also called an "Order Definition Point". The idea is that frames dequeued from a given FQ (ODP) may get out-of-sequence during processing before they're enqueued onto an egress FQ, so the enqueue function allows one to not only specify the desination FQD, but also an ORP that the enqueue command should first pass through - which might hold up the intended enqueue until other, missing, sequence elements are enqueued.

Thanks,

Yiping

sedat_altun · ‎08-12-2019

Thank you very much for your quick reply.