From: John Hubbard <jhubbard@nvidia.com>
To: Linus Torvalds <torvalds@linux-foundation.org>,
Peter Xu <peterx@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>,
Leon Romanovsky <leonro@nvidia.com>,
Linux-MM <linux-mm@kvack.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
"Maya B . Gokhale" <gokhale2@llnl.gov>,
"Yang Shi" <yang.shi@linux.alibaba.com>,
Marty Mcfadden <mcfadden8@llnl.gov>,
"Kirill Shutemov" <kirill@shutemov.name>,
Oleg Nesterov <oleg@redhat.com>, Jann Horn <jannh@google.com>,
Jan Kara <jack@suse.cz>, Kirill Tkhai <ktkhai@virtuozzo.com>,
Andrea Arcangeli <aarcange@redhat.com>,
"Christoph Hellwig" <hch@lst.de>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH 1/4] mm: Trial do_wp_page() simplification
Date: Thu, 17 Sep 2020 12:55:34 -0700 [thread overview]
Message-ID: <29a76f98-ddc5-4fc1-92ed-3eff01130b11@nvidia.com> (raw)
In-Reply-To: <CAHk-=wgw3GNyF_6euymOFxM62Y3B=C=f2iUJn8Py-u5YELJ5JA@mail.gmail.com>
On 9/17/20 12:42 PM, Linus Torvalds wrote:
> On Thu, Sep 17, 2020 at 12:03 PM Peter Xu <peterx@redhat.com> wrote:
...
>
> Is there possibly somethign else we can filter on than just
> GUP_PIN_COUNTING_BIAS? Because it could be as simple as just marking
> the vma itself and saying "this vma has had a page pinning event done
> on it".
>
> Because if we only start copying the page *iff* the vma is marked by
> that "this vma had page pinning" _and_ the page count is bigger than
> GUP_PIN_COUNTING_BIAS, than I think we can rest pretty easily knowing
> that we aren't going to hit some regular old-fashioned UNIX server
> cases with a lot of forks..
>
> Linus
OK, so this sounds like an improvement that would be desirable in the
core API:
1) Have all the pin_user_pages*() functions reach up and mark the vma(s)
as FOLL_PIN_HAPPENED. I'm assuming that the vma can live it's full life
without the need to ever clear that flag. That *seems* reasonable, based
on the use cases for these kinds of pages.
2) And then rename:
page_maybe_dma_pinned() --> page_likely_dma_pinned()
:)
thanks,
--
John Hubbard
NVIDIA
next prev parent reply other threads:[~2020-09-17 19:55 UTC|newest]
Thread overview: 114+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-21 23:49 [PATCH 0/4] mm: Simplfy cow handling Peter Xu
2020-08-21 23:49 ` [PATCH 1/4] mm: Trial do_wp_page() simplification Peter Xu
2020-08-24 8:36 ` Kirill Tkhai
2020-08-24 14:30 ` Jan Kara
2020-08-24 15:37 ` Kirill Tkhai
2020-08-24 18:22 ` Linus Torvalds
2020-08-24 18:22 ` Linus Torvalds
2020-09-01 7:01 ` Hugh Dickins
2020-09-01 7:01 ` Hugh Dickins
2020-09-14 14:38 ` Jason Gunthorpe
2020-09-14 17:32 ` Linus Torvalds
2020-09-14 17:32 ` Linus Torvalds
2020-09-14 18:34 ` Peter Xu
2020-09-14 21:15 ` Peter Xu
2020-09-14 22:55 ` Jason Gunthorpe
2020-09-14 22:59 ` Linus Torvalds
2020-09-14 22:59 ` Linus Torvalds
2020-09-14 23:28 ` Jason Gunthorpe
2020-09-15 0:19 ` Linus Torvalds
2020-09-15 0:19 ` Linus Torvalds
2020-09-15 14:50 ` Peter Xu
2020-09-15 15:17 ` Peter Xu
2020-09-15 16:05 ` Jason Gunthorpe
2020-09-15 18:29 ` Jason Gunthorpe
2020-09-15 19:13 ` Peter Xu
2020-09-15 19:38 ` Jason Gunthorpe
2020-09-15 21:33 ` Peter Xu
2020-09-15 23:22 ` Jason Gunthorpe
2020-09-16 1:50 ` John Hubbard
2020-09-16 17:48 ` Jason Gunthorpe
2020-09-16 18:46 ` Peter Xu
2020-09-17 11:25 ` Jason Gunthorpe
2020-09-17 18:11 ` Linus Torvalds
2020-09-17 18:11 ` Linus Torvalds
2020-09-17 19:38 ` Jason Gunthorpe
2020-09-17 19:51 ` Linus Torvalds
2020-09-17 19:51 ` Linus Torvalds
2020-09-18 16:40 ` Peter Xu
2020-09-18 17:16 ` Linus Torvalds
2020-09-18 17:16 ` Linus Torvalds
2020-09-18 19:57 ` Peter Xu
2020-09-18 17:32 ` Jason Gunthorpe
2020-09-18 20:40 ` Peter Xu
2020-09-18 20:59 ` Linus Torvalds
2020-09-18 20:59 ` Linus Torvalds
2020-09-19 0:28 ` Jason Gunthorpe
2020-09-18 21:06 ` John Hubbard
2020-09-19 0:01 ` Jason Gunthorpe
2020-09-21 8:35 ` Jan Kara
2020-09-21 12:03 ` Jason Gunthorpe
2022-02-16 16:59 ` Oded Gabbay
2022-02-16 17:24 ` Oded Gabbay
2022-02-16 19:04 ` Linus Torvalds
2022-02-16 19:20 ` Oded Gabbay
2022-02-16 19:24 ` David Hildenbrand
2020-09-21 13:42 ` Michal Hocko
2020-09-21 14:18 ` Peter Xu
2020-09-21 14:28 ` Michal Hocko
2020-09-21 14:38 ` Tejun Heo
2020-09-21 14:43 ` Christian Brauner
2020-09-21 14:55 ` Michal Hocko
2020-09-21 15:04 ` Christian Brauner
2020-09-21 16:06 ` Michal Hocko
2020-09-23 7:53 ` Michal Hocko
2020-09-21 14:41 ` Christian Brauner
2020-09-21 14:57 ` Michal Hocko
2020-09-21 16:31 ` Peter Xu
2020-09-17 18:14 ` Peter Xu
2020-09-17 18:26 ` Linus Torvalds
2020-09-17 18:26 ` Linus Torvalds
2020-09-17 19:03 ` Peter Xu
2020-09-17 19:42 ` Linus Torvalds
2020-09-17 19:42 ` Linus Torvalds
2020-09-17 19:55 ` John Hubbard [this message]
2020-09-17 20:06 ` Jason Gunthorpe
2020-09-17 20:19 ` John Hubbard
2020-09-17 20:25 ` Jason Gunthorpe
2020-09-17 20:35 ` Linus Torvalds
2020-09-17 20:35 ` Linus Torvalds
2020-09-17 21:40 ` Peter Xu
2020-09-17 22:09 ` Jason Gunthorpe
2020-09-17 22:25 ` Linus Torvalds
2020-09-17 22:25 ` Linus Torvalds
2020-09-17 22:48 ` Ira Weiny
2020-09-18 9:36 ` Jan Kara
2020-09-18 9:44 ` Jan Kara
2020-09-18 16:19 ` Jason Gunthorpe
2020-09-15 10:23 ` Leon Romanovsky
2020-09-15 15:56 ` Jason Gunthorpe
2020-09-15 15:03 ` Oleg Nesterov
2020-09-15 16:18 ` Peter Xu
2020-08-21 23:49 ` [PATCH 2/4] mm/ksm: Remove reuse_ksm_page() Peter Xu
2020-08-21 23:49 ` [PATCH 3/4] mm/gup: Remove enfornced COW mechanism Peter Xu
2020-09-14 14:27 ` Oleg Nesterov
2020-09-14 17:59 ` Peter Xu
2020-09-14 19:03 ` Linus Torvalds
2020-09-14 19:03 ` Linus Torvalds
2020-08-21 23:49 ` [PATCH 4/4] mm: Add PGREUSE counter Peter Xu
2020-08-22 16:14 ` Linus Torvalds
2020-08-22 16:14 ` Linus Torvalds
2020-08-24 0:24 ` Peter Xu
2020-08-22 16:05 ` [PATCH 0/4] mm: Simplfy cow handling Linus Torvalds
2020-08-22 16:05 ` Linus Torvalds
2020-08-23 23:58 ` Peter Xu
2020-08-24 8:38 ` Kirill Tkhai
2020-08-27 14:15 ` Peter Xu
2021-02-02 14:40 [PATCH 1/4] mm: Trial do_wp_page() simplification Gal Pressman
2021-02-02 16:31 ` Peter Xu
2021-02-02 16:44 ` Jason Gunthorpe
2021-02-02 17:05 ` Peter Xu
2021-02-02 17:13 ` Jason Gunthorpe
2021-02-03 12:43 ` Gal Pressman
2021-02-03 14:00 ` Jason Gunthorpe
2021-02-03 14:47 ` Gal Pressman
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=29a76f98-ddc5-4fc1-92ed-3eff01130b11@nvidia.com \
--to=jhubbard@nvidia.com \
--cc=aarcange@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=gokhale2@llnl.gov \
--cc=hch@lst.de \
--cc=jack@suse.cz \
--cc=jannh@google.com \
--cc=jgg@ziepe.ca \
--cc=kirill@shutemov.name \
--cc=ktkhai@virtuozzo.com \
--cc=leonro@nvidia.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mcfadden8@llnl.gov \
--cc=oleg@redhat.com \
--cc=peterx@redhat.com \
--cc=torvalds@linux-foundation.org \
--cc=yang.shi@linux.alibaba.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 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.