From: Linus Torvalds <torvalds@linux-foundation.org>
To: "Ahmed S. Darwish" <a.darwish@linutronix.de>
Cc: John Hubbard <jhubbard@nvidia.com>,
Jason Gunthorpe <jgg@nvidia.com>, Peter Xu <peterx@redhat.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Andrea Arcangeli <aarcange@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
"Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>,
Christoph Hellwig <hch@lst.de>, Hugh Dickins <hughd@google.com>,
Jan Kara <jack@suse.cz>, Jann Horn <jannh@google.com>,
Kirill Shutemov <kirill@shutemov.name>,
Kirill Tkhai <ktkhai@virtuozzo.com>,
Leon Romanovsky <leonro@nvidia.com>,
Linux-MM <linux-mm@kvack.org>, Michal Hocko <mhocko@suse.com>,
Oleg Nesterov <oleg@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>, Will Deacon <will@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Sebastian Siewior <bigeasy@linutronix.de>
Subject: Re: [PATCH v2 2/2] mm: prevent gup_fast from racing with COW during fork
Date: Tue, 3 Nov 2020 09:40:22 -0800 [thread overview]
Message-ID: <CAHk-=wgB8nyOQufpn0o6a5BpJCJPnXvH+kRxApujhsgG+7qAwQ@mail.gmail.com> (raw)
In-Reply-To: <20201103065225.GA63301@lx-t490>
On Mon, Nov 2, 2020 at 10:52 PM Ahmed S. Darwish
<a.darwish@linutronix.de> wrote:
>
> The problem is, I've already documented seqlock.h to death.... There are
> more comments than code in there, and there is "seqlock.rst" under
> Documentation/ to further describe the big picture.
Well, honestly, I think the correct thing to do is to get rid of the
*_seqcount_t_*() functions entirely.
They add nothing but confusion, and they are entirely misnamed. That's
not the pattern we use for "internal use only" functions, and they are
*very* confusing.
They have other issues too: like raw_write_seqcount_end() not being
usable on its own when preemptibility isn't an issue like here. You
basically _have_ to use raw_write_seqcount_t_end(), because otherwise
it tries to re-enable preemption that was never there.
Linus
next prev parent reply other threads:[~2020-11-03 17:40 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-30 14:46 [PATCH v2 0/2] Add a seqcount between gup_fast and copy_page_range() Jason Gunthorpe
2020-10-30 14:46 ` [PATCH v2 1/2] mm: reorganize internal_get_user_pages_fast() Jason Gunthorpe
2020-10-30 16:29 ` Jan Kara
2020-10-30 21:31 ` John Hubbard
2020-10-30 22:36 ` Peter Xu
2020-10-30 14:46 ` [PATCH v2 2/2] mm: prevent gup_fast from racing with COW during fork Jason Gunthorpe
2020-10-30 16:51 ` Jan Kara
2020-10-30 17:02 ` Jason Gunthorpe
2020-11-02 8:31 ` Jan Kara
2020-10-30 21:20 ` John Hubbard
2020-10-30 22:52 ` Peter Xu
2020-10-30 23:51 ` Jason Gunthorpe
2020-10-31 15:26 ` Peter Xu
2020-11-03 0:33 ` Ahmed S. Darwish
2020-11-03 0:17 ` Ahmed S. Darwish
2020-11-03 0:25 ` Jason Gunthorpe
2020-11-03 0:41 ` Ahmed S. Darwish
2020-11-03 2:20 ` John Hubbard
2020-11-03 6:52 ` Ahmed S. Darwish
2020-11-03 7:05 ` John Hubbard
2020-11-03 17:40 ` Linus Torvalds [this message]
2020-11-04 1:32 ` Ahmed S. Darwish
2020-11-04 2:01 ` John Hubbard
2020-11-04 3:17 ` Ahmed S. Darwish
2020-11-04 18:38 ` Linus Torvalds
2020-11-10 11:53 ` Peter Zijlstra
2020-11-03 17:03 ` Peter Xu
2020-11-02 23:58 ` Ahmed S. Darwish
2020-11-02 22:19 ` [PATCH v2 0/2] Add a seqcount between gup_fast and copy_page_range() Ahmed S. Darwish
2020-11-02 22:39 ` Linus Torvalds
2020-11-02 23:18 ` Ahmed S. Darwish
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='CAHk-=wgB8nyOQufpn0o6a5BpJCJPnXvH+kRxApujhsgG+7qAwQ@mail.gmail.com' \
--to=torvalds@linux-foundation.org \
--cc=a.darwish@linutronix.de \
--cc=aarcange@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=aneesh.kumar@linux.ibm.com \
--cc=bigeasy@linutronix.de \
--cc=hch@lst.de \
--cc=hughd@google.com \
--cc=jack@suse.cz \
--cc=jannh@google.com \
--cc=jgg@nvidia.com \
--cc=jhubbard@nvidia.com \
--cc=kirill@shutemov.name \
--cc=ktkhai@virtuozzo.com \
--cc=leonro@nvidia.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@suse.com \
--cc=mingo@redhat.com \
--cc=oleg@redhat.com \
--cc=peterx@redhat.com \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
--cc=will@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;
as well as URLs for NNTP newsgroup(s).