From: Christoph Hellwig <hch@lst.de>
To: Felix Kuehling <felix.kuehling@amd.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>,
Felix Kuehling <felix.kuehling@gmail.com>,
dri-devel@lists.freedesktop.org, linux-mm@kvack.org,
jglisse@redhat.com, amd-gfx@lists.freedesktop.org,
akpm@linux-foundation.org, hch@lst.de
Subject: Re: [RFC PATCH 0/5] Support DEVICE_GENERIC memory in migrate_vma_*
Date: Sat, 29 May 2021 08:41:24 +0200 [thread overview]
Message-ID: <20210529064124.GC15834@lst.de> (raw)
In-Reply-To: <f0bb142b-ab80-c16e-77dd-c7e1aa88c755@amd.com>
On Fri, May 28, 2021 at 11:56:36AM -0400, Felix Kuehling wrote:
> Am 2021-05-28 um 9:08 a.m. schrieb Jason Gunthorpe:
> > On Thu, May 27, 2021 at 07:08:04PM -0400, Felix Kuehling wrote:
> >> Now we're trying to migrate data to and from that memory using the
> >> migrate_vma_* helpers so we can support page-based migration in our
> >> unified memory allocations, while also supporting CPU access to those
> >> pages.
> > So you have completely coherent and indistinguishable GPU and CPU
> > memory and the need of migration is basicaly alot like NUMA policy
> > choice - get better access locality?
>
> Yes. For a typical GPU compute application it means the GPU gets the
> best bandwidth/latency, and the CPU can coherently access the results
> without page faults and migrations. That's especially valuable for
> applications with persistent compute kernels that want to exploit
> concurrency between CPU and GPU.
So why not expose the GPU memory as a CPUless memory node?
next prev parent reply other threads:[~2021-05-29 6:41 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-27 23:08 [RFC PATCH 0/5] Support DEVICE_GENERIC memory in migrate_vma_* Felix Kuehling
2021-05-27 23:08 ` [RFC PATCH 1/5] drm/amdkfd: add SPM support for SVM Felix Kuehling
2021-05-29 6:38 ` Christoph Hellwig
2021-05-29 18:42 ` Felix Kuehling
2021-05-27 23:08 ` [RFC PATCH 2/5] drm/amdkfd: generic type as sys mem on migration to ram Felix Kuehling
2021-05-27 23:08 ` [RFC PATCH 3/5] include/linux/mm.h: helper to check zone device generic type Felix Kuehling
2021-05-27 23:08 ` [RFC PATCH 4/5] mm: add generic type support for device zone page migration Felix Kuehling
2021-05-29 6:40 ` Christoph Hellwig
2021-05-27 23:08 ` [RFC PATCH 5/5] mm: changes to unref pages with Generic type Felix Kuehling
2021-05-29 6:42 ` Christoph Hellwig
2021-05-29 18:44 ` Felix Kuehling
2021-05-28 13:08 ` [RFC PATCH 0/5] Support DEVICE_GENERIC memory in migrate_vma_* Jason Gunthorpe
2021-05-28 15:56 ` Felix Kuehling
2021-05-29 6:41 ` Christoph Hellwig [this message]
2021-05-29 18:37 ` Felix Kuehling
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=20210529064124.GC15834@lst.de \
--to=hch@lst.de \
--cc=akpm@linux-foundation.org \
--cc=amd-gfx@lists.freedesktop.org \
--cc=dri-devel@lists.freedesktop.org \
--cc=felix.kuehling@amd.com \
--cc=felix.kuehling@gmail.com \
--cc=jgg@nvidia.com \
--cc=jglisse@redhat.com \
--cc=linux-mm@kvack.org \
/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).