On Mon, Oct 11, 2021 at 2:42 PM Thomas Monjalon <tho...@monjalon.net> wrote: > > 11/10/2021 10:43, Jerin Jacob: > > On Mon, Oct 11, 2021 at 1:48 PM Thomas Monjalon <tho...@monjalon.net> wrote: > > > 10/10/2021 12:16, Jerin Jacob: > > > > On Fri, Oct 8, 2021 at 11:13 PM <eagost...@nvidia.com> wrote: > > > > > > > > > > From: eagostini <eagost...@nvidia.com> > > > > > > > > > > In heterogeneous computing system, processing is not only in the CPU. > > > > > Some tasks can be delegated to devices working in parallel. > > > > > > > > > > The goal of this new library is to enhance the collaboration between > > > > > DPDK, that's primarily a CPU framework, and GPU devices. > > > > > > > > > > When mixing network activity with task processing on a non-CPU device, > > > > > there may be the need to put in communication the CPU with the device > > > > > in order to manage the memory, synchronize operations, exchange info, > > > > > etc.. > > > > > > > > > > This library provides a number of new features: > > > > > - Interoperability with GPU-specific library with generic handlers > > > > > - Possibility to allocate and free memory on the GPU > > > > > - Possibility to allocate and free memory on the CPU but visible from > > > > > the GPU > > > > > - Communication functions to enhance the dialog between the CPU and > > > > > the GPU > > > > > > > > In the RFC thread, There was one outstanding non technical issues on > > > > this, > > > > > > > > i.e > > > > The above features are driver specific details. Does the DPDK > > > > _application_ need to be aware of this? > > > > > > I don't see these features as driver-specific. > > > > That is the disconnect. I see this as more driver-specific details > > which are not required to implement an "application" facing API. > > Indeed this is the disconnect. > I already answered but it seems you don't accept the answer.
Same with you. That is why I requested, we need to get opinions from others. Some of them already provided opinions in RFC. > > First, this is not driver-specific. It is a low-level API. What is the difference between low-level API and driver-level API. > > > For example, If we need to implement application facing" subsystems like > > bbdev, > > If we make all this driver interface, you can still implement the > > bbdev API as a driver without > > exposing HW specific details like how devices communicate to CPU, how > > memory is allocated etc > > to "application". > > There are 2 things to understand here. > > First we want to allow the application using the GPU for needs which are > not exposed by any other DPDK API. > > Second, if we want to implement another DPDK API like bbdev, > then the GPU implementation would be exposed as a vdev in bbdev, > using the HW GPU device being a PCI in gpudev. > They are two different levels, got it? Exactly. So what is the point of exposing low-level driver API to "application", why not it is part of the internal driver API. My point is, why the application needs to worry about, How the CPU <-> Device communicated? CPU < -> Device memory visibility etc. > > > > > aka DPDK device class has a fixed personality and it has API to deal > > > > with abstracting specific application specific > > > > end user functionality like ethdev, cryptodev, eventdev irrespective > > > > of underlying bus/device properties. > > > > > > The goal of the lib is to allow anyone to invent any feature > > > which is not already available in DPDK. > > > > > > > Even similar semantics are required for DPU(Smart NIC) > > > > communitication. I am planning to > > > > send RFC in coming days to address the issue without the application > > > > knowing the Bus/HW/Driver details. > > > > > > gpudev is not exposing bus/hw/driver details. > > > I don't understand what you mean. > > > > See above. > > >
