Re: [dpdk-dev] [PATCH v3 0/9] GPU library

[Thomas Monjalon <thomas@monjalon.net>]

10/10/2021 12:16, Jerin Jacob:
> On Fri, Oct 8, 2021 at 11:13 PM <eagostini@nvidia.com> wrote:
> >
> > From: eagostini <eagostini@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.

> 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.

> Irrespective of the RFC I am planning to send and since the new
> library needs techboard approval, You may
> request that the techboard decide approval for this library. Also, As
> far as I remember a minimum a SW driver in
> additional to HW driver to accept a new driver class.

No, only one driver is required:
"When introducing a new device API, at least one driver should implement it."
Anyway, a SW driver doesn't make sense for gpudev.