linux-pci.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
To: Jerome Glisse <j.glisse@gmail.com>
Cc: "Deucher, Alexander" <Alexander.Deucher@amd.com>,
	"'linux-kernel@vger.kernel.org'" <linux-kernel@vger.kernel.org>,
	"'linux-rdma@vger.kernel.org'" <linux-rdma@vger.kernel.org>,
	"'linux-nvdimm@lists.01.org'" <linux-nvdimm@ml01.01.org>,
	"'Linux-media@vger.kernel.org'" <Linux-media@vger.kernel.org>,
	"'dri-devel@lists.freedesktop.org'"
	<dri-devel@lists.freedesktop.org>,
	"'linux-pci@vger.kernel.org'" <linux-pci@vger.kernel.org>,
	"Kuehling, Felix" <Felix.Kuehling@amd.com>,
	"Sagalovitch, Serguei" <Serguei.Sagalovitch@amd.com>,
	"Blinzer, Paul" <Paul.Blinzer@amd.com>,
	"Koenig, Christian" <Christian.Koenig@amd.com>,
	"Suthikulpanit, Suravee" <Suravee.Suthikulpanit@amd.com>,
	"Sander, Ben" <ben.sander@amd.com>,
	hch@infradead.org, david1.zhou@amd.com, qiang.yu@amd.com
Subject: Re: Enabling peer to peer device transactions for PCIe devices
Date: Thu, 5 Jan 2017 12:01:13 -0700	[thread overview]
Message-ID: <20170105190113.GA12587@obsidianresearch.com> (raw)
In-Reply-To: <20170105183927.GA5324@gmail.com>

On Thu, Jan 05, 2017 at 01:39:29PM -0500, Jerome Glisse wrote:

>   1) peer-to-peer because of userspace specific API like NVidia GPU
>     direct (AMD is pushing its own similar API i just can't remember
>     marketing name). This does not happen through a vma, this happens
>     through specific device driver call going through device specific
>     ioctl on both side (GPU and RDMA). So both kernel driver are aware
>     of each others.

Today you can only do user-initiated RDMA operations in conjection
with a VMA.

We'd need a really big and strong reason to create an entirely new
non-VMA based memory handle scheme for RDMA.

So my inclination is to just completely push back on this idea. You
need a VMA to do RMA.

GPUs need to create VMAs for the memory they want to RDMA from, even
if the VMA handle just causes SIGBUS for any CPU access.

Jason

  reply	other threads:[~2017-01-05 19:01 UTC|newest]

Thread overview: 126+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-11-21 20:36 Enabling peer to peer device transactions for PCIe devices Deucher, Alexander
2016-11-22 18:11 ` Dan Williams
     [not found]   ` <75a1f44f-c495-7d1e-7e1c-17e89555edba@amd.com>
2016-11-22 20:01     ` Dan Williams
2016-11-22 20:10       ` Daniel Vetter
2016-11-22 20:24         ` Dan Williams
2016-11-22 20:35         ` Serguei Sagalovitch
2016-11-22 21:03           ` Daniel Vetter
2016-11-22 21:21             ` Dan Williams
2016-11-22 22:21               ` Sagalovitch, Serguei
2016-11-23  7:49               ` Daniel Vetter
2016-11-23  8:51                 ` Christian König
2016-11-23 19:27                   ` Serguei Sagalovitch
2016-11-23 17:03                 ` Dave Hansen
2016-11-23 17:13     ` Logan Gunthorpe
2016-11-23 17:27       ` Bart Van Assche
2016-11-23 18:40         ` Dan Williams
2016-11-23 19:12           ` Jason Gunthorpe
2016-11-23 19:24             ` Serguei Sagalovitch
2016-11-23 19:06         ` Serguei Sagalovitch
2016-11-23 19:05       ` Jason Gunthorpe
2016-11-23 19:14         ` Serguei Sagalovitch
2016-11-23 19:32           ` Jason Gunthorpe
     [not found]             ` <c2c88376-5ba7-37d1-4d3e-592383ebb00a@amd.com>
2016-11-23 20:33               ` Jason Gunthorpe
2016-11-23 21:11                 ` Logan Gunthorpe
2016-11-23 21:55                   ` Jason Gunthorpe
2016-11-23 22:42                     ` Dan Williams
2016-11-23 23:25                       ` Jason Gunthorpe
2016-11-24  9:45                         ` Christian König
2016-11-24 16:26                           ` Jason Gunthorpe
2016-11-24 17:00                             ` Serguei Sagalovitch
2016-11-24 17:55                           ` Logan Gunthorpe
2016-11-25 13:06                             ` Christian König
2016-11-25 16:45                               ` Logan Gunthorpe
2016-11-25 17:20                                 ` Serguei Sagalovitch
2016-11-25 20:26                                   ` Felix Kuehling
2016-11-25 20:48                                     ` Serguei Sagalovitch
2016-11-24  0:40                     ` Sagalovitch, Serguei
2016-11-24 16:24                       ` Jason Gunthorpe
2016-11-24  1:25                     ` Logan Gunthorpe
2016-11-24 16:42                       ` Jason Gunthorpe
2016-11-24 18:11                         ` Logan Gunthorpe
2016-11-25  7:58                           ` Christoph Hellwig
2016-11-25 19:41                             ` Jason Gunthorpe
2016-11-25 17:59                           ` Serguei Sagalovitch
2016-11-25 13:22                         ` Christian König
2016-11-25 17:16                           ` Serguei Sagalovitch
2016-11-25 19:34                             ` Jason Gunthorpe
2016-11-25 19:49                               ` Serguei Sagalovitch
2016-11-25 20:19                                 ` Jason Gunthorpe
2016-11-25 23:41                               ` Alex Deucher
2016-11-25 19:32                           ` Jason Gunthorpe
2016-11-25 20:40                             ` Christian König
2016-11-25 20:51                               ` Felix Kuehling
2016-11-25 21:18                               ` Jason Gunthorpe
2016-11-27  8:16                             ` Haggai Eran
2016-11-27 14:02                             ` Haggai Eran
2016-11-27 14:07                               ` Christian König
2016-11-28  5:31                                 ` zhoucm1
2016-11-28 14:48                               ` Serguei Sagalovitch
2016-11-28 18:36                                 ` Haggai Eran
2016-11-28 16:57                               ` Jason Gunthorpe
2016-11-28 18:19                                 ` Haggai Eran
2016-11-28 19:02                                   ` Jason Gunthorpe
2016-11-30 10:45                                     ` Haggai Eran
2016-11-30 16:23                                       ` Jason Gunthorpe
2016-11-30 17:28                                         ` Serguei Sagalovitch
2016-12-04  7:33                                           ` Haggai Eran
2016-11-30 18:01                                         ` Logan Gunthorpe
2016-12-04  7:42                                           ` Haggai Eran
2016-12-04 13:06                                             ` Stephen Bates
2016-12-04 13:23                                             ` Stephen Bates
2016-12-05 17:18                                               ` Jason Gunthorpe
2016-12-05 17:40                                                 ` Dan Williams
2016-12-05 18:02                                                   ` Jason Gunthorpe
2016-12-05 18:08                                                     ` Dan Williams
2016-12-05 18:39                                                       ` Logan Gunthorpe
2016-12-05 18:48                                                         ` Dan Williams
2016-12-05 19:14                                                           ` Jason Gunthorpe
2016-12-05 19:27                                                             ` Logan Gunthorpe
2016-12-05 19:46                                                               ` Jason Gunthorpe
2016-12-05 19:59                                                                 ` Logan Gunthorpe
2016-12-05 20:06                                                                 ` Christoph Hellwig
2016-12-06  8:06                                                           ` Stephen Bates
2016-12-06 16:38                                                             ` Jason Gunthorpe
2016-12-06 16:51                                                               ` Logan Gunthorpe
2016-12-06 17:28                                                                 ` Jason Gunthorpe
2016-12-06 21:47                                                                   ` Logan Gunthorpe
2016-12-06 22:02                                                                     ` Dan Williams
2016-12-06 17:12                                                               ` Christoph Hellwig
2016-12-04  7:53                                         ` Haggai Eran
2016-11-30 17:10                                       ` Deucher, Alexander
2016-11-28 18:20                                 ` Logan Gunthorpe
2016-11-28 19:35                                   ` Serguei Sagalovitch
2016-11-28 21:36                                     ` Logan Gunthorpe
2016-11-28 21:55                                       ` Serguei Sagalovitch
2016-11-28 22:24                                         ` Jason Gunthorpe
2017-01-05 18:39 ` Jerome Glisse
2017-01-05 19:01   ` Jason Gunthorpe [this message]
2017-01-05 19:54     ` Jerome Glisse
2017-01-05 20:07       ` Jason Gunthorpe
2017-01-05 20:19         ` Jerome Glisse
2017-01-05 22:42           ` Jason Gunthorpe
2017-01-05 23:23             ` Jerome Glisse
2017-01-06  0:30               ` Jason Gunthorpe
2017-01-06  0:41                 ` Serguei Sagalovitch
2017-01-06  1:58                 ` Jerome Glisse
2017-01-06 16:56                   ` Serguei Sagalovitch
2017-01-06 17:37                     ` Jerome Glisse
2017-01-06 18:26                       ` Jason Gunthorpe
2017-01-06 19:12                         ` Deucher, Alexander
2017-01-06 22:10                         ` Logan Gunthorpe
2017-01-12  4:54                           ` Stephen Bates
2017-01-12 15:11                             ` Jerome Glisse
2017-01-12 17:17                               ` Jason Gunthorpe
2017-01-13 13:04                               ` Christian König
2017-01-12 22:35                             ` Logan Gunthorpe
2017-01-06 15:08     ` Henrique Almeida
2017-10-20 12:36 ` Ludwig Petrosyan
2017-10-20 15:48   ` Logan Gunthorpe
2017-10-22  6:13     ` Petrosyan, Ludwig
2017-10-22 17:19       ` Logan Gunthorpe
2017-10-23 16:08       ` David Laight
2017-10-23 22:04         ` Logan Gunthorpe
2017-10-24  5:58           ` Petrosyan, Ludwig
2017-10-24 14:58             ` David Laight
2017-10-26 13:28               ` Petrosyan, Ludwig

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20170105190113.GA12587@obsidianresearch.com \
    --to=jgunthorpe@obsidianresearch.com \
    --cc=Alexander.Deucher@amd.com \
    --cc=Christian.Koenig@amd.com \
    --cc=Felix.Kuehling@amd.com \
    --cc=Linux-media@vger.kernel.org \
    --cc=Paul.Blinzer@amd.com \
    --cc=Serguei.Sagalovitch@amd.com \
    --cc=Suravee.Suthikulpanit@amd.com \
    --cc=ben.sander@amd.com \
    --cc=david1.zhou@amd.com \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=hch@infradead.org \
    --cc=j.glisse@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-nvdimm@ml01.01.org \
    --cc=linux-pci@vger.kernel.org \
    --cc=linux-rdma@vger.kernel.org \
    --cc=qiang.yu@amd.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).