From: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
To: Jason Gunthorpe <jgg@nvidia.com>
Cc: "Wan, Kaike" <kaike.wan@intel.com>,
"dledford@redhat.com" <dledford@redhat.com>,
"linux-rdma@vger.kernel.org" <linux-rdma@vger.kernel.org>,
"Rimmer, Todd" <todd.rimmer@intel.com>
Subject: Re: [PATCH RFC 0/9] A rendezvous module
Date: Fri, 19 Mar 2021 16:18:56 -0400 [thread overview]
Message-ID: <ed0d861c-4352-8568-b3c0-31a0f1eac228@cornelisnetworks.com> (raw)
In-Reply-To: <20210319194446.GA2356281@nvidia.com>
On 3/19/2021 3:44 PM, Jason Gunthorpe wrote:
> On Fri, Mar 19, 2021 at 03:22:45PM -0400, Dennis Dalessandro wrote:
>
>>>> [Wan, Kaike] I think that you are referring to PSM2, which uses the
>>>> OPA hfi1 driver that is specific to the OPA hardware. PSM3 uses
>>>> standard verbs drivers and supports standard RoCE.
>>>
>>> Uhhh.. "PSM" has always been about the ipath special char device, and
>>> if I recall properly the library was semi-discontinued and merged into
>>> libfabric.
>>
>> This driver is intended to work with a fork of the PSM2 library. The PSM2
>> library which is for Omni-Path is now maintained by Cornelis Networks on our
>> GitHub. PSM3 is something from Intel for Ethernet. I know it's a bit
>> confusing.
>
> "a bit" huh?
Just a bit. :)
>
>>> So here you are talking about a libfabric verbs provider that doesn't
>>> use the ipath style char interface but uses verbs and this rv thing so
>>> we call it a libfabric PSM3 provider because thats not confusing to
>>> anyone at all..
>>>
>>>> A focus is the Intel RDMA Ethernet NICs. As such it cannot use the
>>>> hfi1 driver through the special PSM2 interface.
>>>
>>> These are the drivers that aren't merged yet, I see. So why are you
>>> sending this now? I'm not interested to look at even more Intel code
>>> when their driver saga is still ongoing for years.
>>>
>>>> Rather it works with the hfi1 driver through standard verbs
>>>> interface.
>>>
>>> But nobody would do that right? You'd get better results using the
>>> hif1 native interfaces instead of their slow fake verbs stuff.
>>
>> I can't imagine why. I'm not sure what you mean by our slow fake verbs
>> stuff? We support verbs just fine. It's certainly not fake.
>
> hfi1 calls to the kernel for data path operations - that is "fake" in
> my book. Verbs was always about avoiding that kernel transition, to
> put it back in betrays the spirit. So a kernel call for rv, or the hfi
> cdev, or the verbs post-send is really all a wash.
Probably better to argue that in another thread I guess.
> I didn't understand your answer, do you see using this with hfi1 or
> not?
I don't see how this could ever use hfi1. So no.
> It looks a lot copy&pasted from the hfi1 driver, so now we are on our
> third copy of this code :(
I haven't had a chance to look beyond the cover letter in depth at how
things have changed. I really hope it's not that bad.
> And why did it suddenly become a ULP that somehow shares uverbs
> resources?? I'm pretty skeptical that can be made to work correctly..
I see your point.
I was just providing some background/clarification. Bottom line this has
nothing to do with hfi1 or OPA or PSM2.
-Denny
next prev parent reply other threads:[~2021-03-19 20:19 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-19 12:56 [PATCH RFC 0/9] A rendezvous module kaike.wan
2021-03-19 12:56 ` [PATCH RFC 1/9] RDMA/rv: Public interferce for the RDMA Rendezvous module kaike.wan
2021-03-19 16:00 ` Jason Gunthorpe
2021-03-19 12:56 ` [PATCH RFC 2/9] RDMA/rv: Add the internal header files kaike.wan
2021-03-19 16:02 ` Jason Gunthorpe
2021-03-19 12:56 ` [PATCH RFC 3/9] RDMA/rv: Add the rv module kaike.wan
2021-03-19 12:56 ` [PATCH RFC 4/9] RDMA/rv: Add functions for memory region cache kaike.wan
2021-03-19 12:56 ` [PATCH RFC 5/9] RDMA/rv: Add function to register/deregister memory region kaike.wan
2021-03-19 12:56 ` [PATCH RFC 6/9] RDMA/rv: Add connection management functions kaike.wan
2021-03-19 12:56 ` [PATCH RFC 7/9] RDMA/rv: Add functions for RDMA transactions kaike.wan
2021-03-19 12:56 ` [PATCH RFC 8/9] RDMA/rv: Add functions for file operations kaike.wan
2021-03-19 12:56 ` [PATCH RFC 9/9] RDMA/rv: Integrate the file operations into the rv module kaike.wan
2021-03-19 13:53 ` [PATCH RFC 0/9] A rendezvous module Jason Gunthorpe
2021-03-19 14:49 ` Wan, Kaike
2021-03-19 15:48 ` Jason Gunthorpe
2021-03-19 19:22 ` Dennis Dalessandro
2021-03-19 19:44 ` Jason Gunthorpe
2021-03-19 20:12 ` Rimmer, Todd
2021-03-19 20:26 ` Jason Gunthorpe
2021-03-19 20:46 ` Rimmer, Todd
2021-03-19 20:54 ` Jason Gunthorpe
2021-03-19 20:59 ` Wan, Kaike
2021-03-19 21:28 ` Dennis Dalessandro
2021-03-19 21:58 ` Wan, Kaike
2021-03-19 22:35 ` Jason Gunthorpe
2021-03-19 22:57 ` Rimmer, Todd
2021-03-19 23:06 ` Jason Gunthorpe
2021-03-20 16:39 ` Dennis Dalessandro
2021-03-21 8:56 ` Leon Romanovsky
2021-03-21 16:24 ` Dennis Dalessandro
2021-03-21 16:45 ` Jason Gunthorpe
2021-03-21 17:21 ` Dennis Dalessandro
2021-03-21 18:08 ` Jason Gunthorpe
2021-03-22 15:17 ` Rimmer, Todd
2021-03-22 16:47 ` Jason Gunthorpe
2021-03-22 17:31 ` Hefty, Sean
2021-03-23 22:56 ` Jason Gunthorpe
2021-03-23 23:29 ` Rimmer, Todd
2021-03-21 19:19 ` Wan, Kaike
2021-03-23 15:36 ` Christoph Hellwig
2021-03-23 15:35 ` Christoph Hellwig
2021-03-23 15:33 ` Christoph Hellwig
2021-03-23 15:30 ` Christoph Hellwig
2021-03-23 15:46 ` Jason Gunthorpe
2021-03-23 16:07 ` Christoph Hellwig
2021-03-23 17:25 ` Rimmer, Todd
2021-03-23 17:44 ` Jason Gunthorpe
2021-03-19 20:18 ` Dennis Dalessandro [this message]
2021-03-19 20:30 ` Jason Gunthorpe
2021-03-19 20:34 ` Hefty, Sean
2021-03-21 12:08 ` Jason Gunthorpe
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