From: Christoph Hellwig <hch@infradead.org>
To: John Hubbard <jhubbard@nvidia.com>
Cc: Christoph Hellwig <hch@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
LKML <linux-kernel@vger.kernel.org>,
linux-mm@kvack.org, linux-stable@vger.kernel.org,
Vivek Kasireddy <vivek.kasireddy@intel.com>,
David Hildenbrand <david@redhat.com>,
Dave Airlie <airlied@redhat.com>,
Gerd Hoffmann <kraxel@redhat.com>,
Matthew Wilcox <willy@infradead.org>,
Jason Gunthorpe <jgg@nvidia.com>, Peter Xu <peterx@redhat.com>,
Arnd Bergmann <arnd@arndb.de>,
Daniel Vetter <daniel.vetter@ffwll.ch>,
Dongwon Kim <dongwon.kim@intel.com>,
Hugh Dickins <hughd@google.com>,
Junxiao Chang <junxiao.chang@intel.com>,
Mike Kravetz <mike.kravetz@oracle.com>,
Oscar Salvador <osalvador@suse.de>
Subject: Re: [PATCH] mm/gup: restore the ability to pin more than 2GB at a time
Date: Tue, 29 Oct 2024 21:33:28 -0700 [thread overview]
Message-ID: <ZyG3GAvTHpRL9tnU@infradead.org> (raw)
In-Reply-To: <249d2614-0bcc-4ca8-b24e-7c0578a81dce@nvidia.com>
On Tue, Oct 29, 2024 at 09:30:41PM -0700, John Hubbard wrote:
> I do, yes. And what happens is that when you use GPUs, drivers like
> to pin system memory, and then point the GPU page tables to that
> memory. For older GPUs that don't support replayable page faults,
> that's required.
>
> So this behavior has been around forever.
>
> The customer was qualifying their software and noticed that before
> Linux 6.10, they could allocate >2GB, and with 6.11, they could
> not.
>
> Whether it is "wise" for user space to allocate that much at once
> is a reasonable question, but at least one place is (or was!) doing
> it.
Still missing a callchain, which make me suspect that it is your weird
out of tree driver, in which case this simply does not matter.
next prev parent reply other threads:[~2024-10-30 4:33 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-30 3:01 [PATCH] mm/gup: restore the ability to pin more than 2GB at a time John Hubbard
2024-10-30 3:02 ` kernel test robot
2024-10-30 3:10 ` John Hubbard
2024-10-30 4:21 ` Christoph Hellwig
2024-10-30 4:30 ` John Hubbard
2024-10-30 4:33 ` Christoph Hellwig [this message]
2024-10-30 4:39 ` John Hubbard
2024-10-30 4:42 ` Christoph Hellwig
2024-10-30 4:44 ` John Hubbard
2024-10-30 6:18 ` Alistair Popple
2024-10-30 6:50 ` John Hubbard
2024-10-30 8:34 ` David Hildenbrand
2024-10-30 9:01 ` David Hildenbrand
2024-10-30 18:34 ` John Hubbard
2024-10-31 0:02 ` Jason Gunthorpe
2024-10-31 0:17 ` John Hubbard
2024-10-31 0:25 ` Jason Gunthorpe
2024-10-31 0:47 ` John Hubbard
2024-10-30 12:04 ` Jason Gunthorpe
2024-10-30 17:25 ` John Hubbard
2024-10-30 11:59 ` Jason Gunthorpe
2024-10-30 11:03 ` Vlastimil Babka
2024-10-30 17:29 ` John Hubbard
2024-10-30 17:42 ` Vlastimil Babka
2024-10-30 17:49 ` John Hubbard
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=ZyG3GAvTHpRL9tnU@infradead.org \
--to=hch@infradead.org \
--cc=airlied@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=arnd@arndb.de \
--cc=daniel.vetter@ffwll.ch \
--cc=david@redhat.com \
--cc=dongwon.kim@intel.com \
--cc=hughd@google.com \
--cc=jgg@nvidia.com \
--cc=jhubbard@nvidia.com \
--cc=junxiao.chang@intel.com \
--cc=kraxel@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-stable@vger.kernel.org \
--cc=mike.kravetz@oracle.com \
--cc=osalvador@suse.de \
--cc=peterx@redhat.com \
--cc=vivek.kasireddy@intel.com \
--cc=willy@infradead.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.