linux-kernel - Re: [PATCH v1 0/4] GPU Direct RDMA (P2P DMA) for Device Private Pages

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <5472cead-7965-47f5-9ee1-77d40062b897@linux.dev>
Date: Fri, 18 Oct 2024 09:26:50 +0200
From: Zhu Yanjun <yanjun.zhu@...ux.dev>
To: Yonatan Maman <ymaman@...dia.com>, Christoph Hellwig <hch@...radead.org>
Cc: nouveau@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
 linux-rdma@...r.kernel.org, linux-mm@...ck.org, herbst@...hat.com,
 lyude@...hat.com, dakr@...hat.com, airlied@...il.com, simona@...ll.ch,
 jgg@...pe.ca, leon@...nel.org, jglisse@...hat.com,
 akpm@...ux-foundation.org, dri-devel@...ts.freedesktop.org,
 apopple@...dia.com, bskeggs@...dia.com
Subject: Re: [PATCH v1 0/4] GPU Direct RDMA (P2P DMA) for Device Private Pages

在 2024/10/16 17:16, Yonatan Maman 写道:
> 
> 
> On 16/10/2024 7:23, Christoph Hellwig wrote:
>> On Tue, Oct 15, 2024 at 06:23:44PM +0300, Yonatan Maman wrote:
>>> From: Yonatan Maman <Ymaman@...dia.com>
>>>
>>> This patch series aims to enable Peer-to-Peer (P2P) DMA access in
>>> GPU-centric applications that utilize RDMA and private device pages. 
>>> This
>>> enhancement is crucial for minimizing data transfer overhead by allowing
>>> the GPU to directly expose device private page data to devices such as
>>> NICs, eliminating the need to traverse system RAM, which is the native
>>> method for exposing device private page data.
>>
>> Please tone down your marketing language and explain your factual
>> changes.  If you make performance claims back them by numbers.
>>
> 
> Got it, thanks! I'll fix that. Regarding performance, we’re achieving 
> over 10x higher bandwidth and 10x lower latency using perftest-rdma, 
> especially (with a high rate of GPU memory access).

If I got this patch series correctly, this is based on ODP (On Demand 
Paging). And a way also exists which is based on non-ODP. From the 
following links, this way is implemented on efa, irdma and mlx5.
1. iRDMA
https://lore.kernel.org/all/20230217011425.498847-1-yanjun.zhu@intel.com/

2. efa
https://lore.kernel.org/lkml/20211007114018.GD2688930@ziepe.ca/t/

3. mlx5
https://lore.kernel.org/all/1608067636-98073-5-git-send-email-jianxin.xiong@intel.com/

Because these 2 methods are both implemented on mlx5, have you compared 
the test results with the 2 methods on mlx5?

The most important results should be latency and bandwidth. Please let 
us know the test results.

Thanks a lot.
Zhu Yanjun