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: 38+ 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]
2020-11-03 17:40 ` Linus Torvalds
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
2020-11-04 18:38 ` Linus Torvalds
2020-11-04 19:54 ` Ahmed S. Darwish
2020-12-09 18:38 ` [tip: locking/core] seqlock: Prefix internal seqcount_t-only macros with a "do_" tip-bot2 for Ahmed S. Darwish
2020-12-09 18:38 ` [tip: locking/core] seqlock: kernel-doc: Specify when preemption is automatically altered tip-bot2 for Ahmed S. Darwish
2020-11-10 11:53 ` [PATCH v2 2/2] mm: prevent gup_fast from racing with COW during fork Peter Zijlstra
2020-12-03 10:35 ` [tip: locking/core] seqlock: Rename __seqprop() users tip-bot2 for Peter Zijlstra
2020-11-03 17:03 ` [PATCH v2 2/2] mm: prevent gup_fast from racing with COW during fork 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 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 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.