[dpdk-dev] [PATCH] gpudev: introduce memory API

[Thomas Monjalon]

04/06/2021 15:59, Andrew Rybchenko:
> On 6/4/21 4:18 PM, Thomas Monjalon wrote:
> > 04/06/2021 15:05, Andrew Rybchenko:
> >> On 6/4/21 3:46 PM, Thomas Monjalon wrote:
> >>> 04/06/2021 13:09, Jerin Jacob:
> >>>> On Fri, Jun 4, 2021 at 3:58 PM Thomas Monjalon <thomas at monjalon.net> wrote:
> >>>>> 03/06/2021 11:33, Ferruh Yigit:
> >>>>>> On 6/3/2021 8:47 AM, Jerin Jacob wrote:
> >>>>>>> On Thu, Jun 3, 2021 at 2:05 AM Thomas Monjalon <thomas at monjalon.net> wrote:
> >>>>>>>> +  [gpudev]             (@ref rte_gpudev.h),
> >>>>>>>
> >>>>>>> Since this device does not have a queue etc? Shouldn't make it a
> >>>>>>> library like mempool with vendor-defined ops?
> >>>>>>
> >>>>>> +1
> >>>>>>
> >>>>>> Current RFC announces additional memory allocation capabilities, which can suits
> >>>>>> better as extension to existing memory related library instead of a new device
> >>>>>> abstraction library.
> >>>>>
> >>>>> It is not replacing mempool.
> >>>>> It is more at the same level as EAL memory management:
> >>>>> allocate simple buffer, but with the exception it is done
> >>>>> on a specific device, so it requires a device ID.
> >>>>>
> >>>>> The other reason it needs to be a full library is that
> >>>>> it will start a workload on the GPU and get completion notification
> >>>>> so we can integrate the GPU workload in a packet processing pipeline.
> >>>>
> >>>> I might have confused you. My intention is not to make to fit under mempool API.
> >>>>
> >>>> I agree that we need a separate library for this. My objection is only
> >>>> to not call libgpudev and
> >>>> call it libgpu. And have APIs with rte_gpu_ instead of rte_gpu_dev as
> >>>> it not like existing "device libraries" in DPDK and
> >>>> it like other "libraries" in DPDK.
> >>>
> >>> I think we should define a queue of processing actions,
> >>> so it looks like other device libraries.
> >>> And anyway I think a library managing a device class,
> >>> and having some device drivers deserves the name of device library.
> >>>
> >>> I would like to read more opinions.
> >>
> >> Since the library is an unified interface to GPU device drivers
> >> I think it should be named as in the patch - gpudev.
> >>
> >> Mempool looks like an exception here - initially it was pure SW
> >> library, but not there are HW backends and corresponding device
> >> drivers.
> >>
> >> What I don't understand where is GPU specifics here?
> > 
> > That's an interesting question.
> > Let's ask first what is a GPU for DPDK?
> > I think it is like a sub-CPU with high parallel execution capabilities,
> > and it is controlled by the CPU.
> 
> I have no good ideas how to name it in accordance with
> above description to avoid "G" which for "Graphics" if
> understand correctly. However, may be it is not required.
> No strong opinion on the topic, but unbinding from
> "Graphics" would be nice.

That's a question I ask myself for months now.
I am not able to find a better name,
and I start thinking that "GPU" is famous enough in high-load computing
to convey the idea of what we can expect.