From: Ralph Campbell <rcampbell@nvidia.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org, Felix Kuehling <felix.kuehling@amd.com>,
Philip Yang <Philip.Yang@amd.com>,
Alistair Popple <apopple@nvidia.com>,
Jason Gunthorpe <jgg@nvidia.com>,
stable@vger.kernel.org
Subject: Re: [PATCH] mm/hmm: fault non-owner device private entries
Date: Mon, 25 Jul 2022 12:07:27 -0700 [thread overview]
Message-ID: <e20f27ab-fb31-4301-0683-3ce51818b6b6@nvidia.com> (raw)
In-Reply-To: <20220725114953.7e53ca4b296e0e753ca7bfda@linux-foundation.org>
On 7/25/22 11:49, Andrew Morton wrote:
> On Fri, 22 Jul 2022 15:56:32 -0700 Ralph Campbell <rcampbell@nvidia.com> wrote:
>
>> If hmm_range_fault() is called with the HMM_PFN_REQ_FAULT flag and a
>> device private PTE is found, the hmm_range::dev_private_owner page is
>> used to determine if the device private page should not be faulted in.
>> However, if the device private page is not owned by the caller,
>> hmm_range_fault() returns an error instead of calling migrate_to_ram()
>> to fault in the page.
> Could we please include here a description of the end-user visible
> effects of the bug?
>
>> Cc: stable@vger.kernel.org
> Especially when proposing a -stable backport.
If I add the following, would that be sufficient?
Should I post a v3?
For example, if a page is migrated to GPU private
memory and a RDMA fault capable NIC tries to read the migrated page,
without this patch it will get an error. With this patch, the page will
be migrated back to system memory and the NIC will be able to read the
data.
next prev parent reply other threads:[~2022-07-25 19:07 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-22 22:56 Ralph Campbell
2022-07-23 13:32 ` Jason Gunthorpe
2022-07-25 17:54 ` Ralph Campbell
2022-07-25 9:32 ` Alistair Popple
2022-07-25 17:56 ` Ralph Campbell
2022-07-25 14:08 ` Felix Kuehling
2022-07-25 18:49 ` Andrew Morton
2022-07-25 19:07 ` Ralph Campbell [this message]
2022-07-25 22:29 ` Andrew Morton
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=e20f27ab-fb31-4301-0683-3ce51818b6b6@nvidia.com \
--to=rcampbell@nvidia.com \
--cc=Philip.Yang@amd.com \
--cc=akpm@linux-foundation.org \
--cc=apopple@nvidia.com \
--cc=felix.kuehling@amd.com \
--cc=jgg@nvidia.com \
--cc=linux-mm@kvack.org \
--cc=stable@vger.kernel.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