From: Jason Gunthorpe <jgg@nvidia.com>
To: Peter Xu <peterx@redhat.com>
Cc: David Hildenbrand <david@redhat.com>,
"Kasireddy, Vivek" <vivek.kasireddy@intel.com>,
"dri-devel@lists.freedesktop.org"
<dri-devel@lists.freedesktop.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
Mike Kravetz <mike.kravetz@oracle.com>,
Gerd Hoffmann <kraxel@redhat.com>,
"Kim, Dongwon" <dongwon.kim@intel.com>,
Andrew Morton <akpm@linux-foundation.org>,
James Houghton <jthoughton@google.com>,
Jerome Marchand <jmarchan@redhat.com>,
"Chang, Junxiao" <junxiao.chang@intel.com>,
"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
"Hocko, Michal" <mhocko@suse.com>,
Muchun Song <muchun.song@linux.dev>,
John Hubbard <jhubbard@nvidia.com>
Subject: Re: [PATCH v1 0/2] udmabuf: Add back support for mapping hugetlb pages
Date: Tue, 27 Jun 2023 12:52:34 -0300 [thread overview]
Message-ID: <ZJsFwis9edi3dWr7@nvidia.com> (raw)
In-Reply-To: <ZJnhNSmSv8ynHu3U@x1n>
On Mon, Jun 26, 2023 at 03:04:21PM -0400, Peter Xu wrote:
> On Mon, Jun 26, 2023 at 03:18:48PM -0300, Jason Gunthorpe wrote:
> > On Mon, Jun 26, 2023 at 08:14:27PM +0200, David Hildenbrand wrote:
> >
> > > So we might have to implement the same page migration as gup does on
> > > FOLL_LONGTERM here ... maybe there are more such cases/drivers that actually
> > > require that handling when simply taking pages out of the memfd, believing
> > > they can hold on to them forever.
> >
> > In general I would like to see an interface to FOLL_LONGTERM pin pages
> > from a memfd. I would quite happily use that in iommufd as well.
> >
> > It solves some problems we have there with fork/exec/etc if the pages
> > are not linked to a mm_struct.
>
> Afaiu any fd based approach should mean it'll never work with private
> memories, while mm-based should be able to work on any kind.
Is there a significant use case to open a memfd and then use
MAP_PRIVATE? Why would anyone want to do that instead of just using
normal mmap anonymous memory?
Jason
next prev parent reply other threads:[~2023-06-27 15:52 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-22 7:27 [PATCH v1 0/2] udmabuf: Add back support for mapping hugetlb pages Vivek Kasireddy
2023-06-22 7:27 ` [PATCH v1 1/2] udmabuf: Use vmf_insert_pfn and VM_PFNMAP for handling mmap Vivek Kasireddy
2023-06-22 7:27 ` [PATCH v1 2/2] udmabuf: Add back support for mapping hugetlb pages Vivek Kasireddy
2023-06-22 22:10 ` kernel test robot
2023-06-22 8:25 ` [PATCH v1 0/2] " David Hildenbrand
2023-06-22 21:33 ` Mike Kravetz
2023-06-23 6:13 ` Kasireddy, Vivek
2023-06-23 16:35 ` Peter Xu
2023-06-23 16:37 ` Jason Gunthorpe
2023-06-23 17:28 ` Peter Xu
2023-06-26 12:57 ` Jason Gunthorpe
2023-06-26 7:45 ` Kasireddy, Vivek
2023-06-26 17:52 ` Peter Xu
2023-06-26 18:14 ` David Hildenbrand
2023-06-26 18:18 ` Jason Gunthorpe
2023-06-26 19:04 ` Peter Xu
2023-06-27 15:52 ` Jason Gunthorpe [this message]
2023-06-27 16:00 ` Peter Xu
2023-06-27 16:04 ` Jason Gunthorpe
2023-06-27 6:37 ` Kasireddy, Vivek
2023-06-27 7:10 ` David Hildenbrand
2023-06-28 8:04 ` Kasireddy, Vivek
2023-08-08 16:17 ` Daniel Vetter
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=ZJsFwis9edi3dWr7@nvidia.com \
--to=jgg@nvidia.com \
--cc=akpm@linux-foundation.org \
--cc=david@redhat.com \
--cc=dongwon.kim@intel.com \
--cc=dri-devel@lists.freedesktop.org \
--cc=jhubbard@nvidia.com \
--cc=jmarchan@redhat.com \
--cc=jthoughton@google.com \
--cc=junxiao.chang@intel.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=kraxel@redhat.com \
--cc=linux-mm@kvack.org \
--cc=mhocko@suse.com \
--cc=mike.kravetz@oracle.com \
--cc=muchun.song@linux.dev \
--cc=peterx@redhat.com \
--cc=vivek.kasireddy@intel.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).