From: Linus Torvalds <[email protected]>
To: Jens Axboe <[email protected]>, Ming Lei <[email protected]>
Cc: Andy Lutomirski <[email protected]>,
Dave Chinner <[email protected]>,
Matthew Wilcox <[email protected]>,
Stefan Metzmacher <[email protected]>,
linux-fsdevel <[email protected]>,
Linux API Mailing List <[email protected]>,
io-uring <[email protected]>,
"[email protected]" <[email protected]>,
Al Viro <[email protected]>,
Samba Technical <[email protected]>
Subject: Re: copy on write for splice() from file to pipe?
Date: Fri, 10 Feb 2023 14:08:35 -0800 [thread overview]
Message-ID: <CAHk-=wjzqrD5wrfeaU390bXEEBY2JF-oKmFN4fREzgyXsbQRTQ@mail.gmail.com> (raw)
In-Reply-To: <[email protected]>
On Fri, Feb 10, 2023 at 1:51 PM Jens Axboe <[email protected]> wrote:
>
> Speaking of splice/io_uring, Ming posted this today:
>
> https://lore.kernel.org/io-uring/[email protected]/
Ugh. Some of that is really ugly. Both 'ignore_sig' and
'ack_page_consuming' just look wrong. Pure random special cases.
And that 'ignore_sig' is particularly ugly, since the only thing that
sets it also sets SPLICE_F_NONBLOCK.
And the *only* thing that actually then checks that field is
'splice_from_pipe_next()', where there are exactly two
signal_pending() checks that it adds to, and
(a) the first one is to protect from endless loops
(b) the second one is irrelevant when SPLICE_F_NONBLOCK is set
So honestly, just NAK on that series.
I think that instead of 'ignore_sig' (which shouldn't exist), that
first 'signal_pending()' check in splice_from_pipe_next() should just
be changed into a 'fatal_signal_pending()'.
But that 'ack_page_consuming' thing looks even more disgusting, and
since I'm not sure why it even exists, I don't know what it's doing
wrong.
Let's agree not to make splice() worse, while people are talking about
how bad it already is, ok?
Linus
next prev parent reply other threads:[~2023-02-10 22:09 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-09 13:55 copy on write for splice() from file to pipe? Stefan Metzmacher
2023-02-09 14:11 ` Matthew Wilcox
2023-02-09 14:29 ` Stefan Metzmacher
2023-02-09 16:41 ` Linus Torvalds
2023-02-09 19:17 ` Stefan Metzmacher
2023-02-09 19:36 ` Linus Torvalds
2023-02-09 19:48 ` Linus Torvalds
2023-02-09 20:33 ` Jeremy Allison
2023-02-10 20:45 ` Stefan Metzmacher
2023-02-10 20:51 ` Linus Torvalds
2023-02-10 2:16 ` Dave Chinner
2023-02-10 4:06 ` Dave Chinner
2023-02-10 4:44 ` Matthew Wilcox
2023-02-10 6:57 ` Dave Chinner
2023-02-10 15:14 ` Andy Lutomirski
2023-02-10 16:33 ` Linus Torvalds
2023-02-10 17:57 ` Andy Lutomirski
2023-02-10 18:19 ` Jeremy Allison
2023-02-10 19:29 ` Stefan Metzmacher
2023-02-10 18:37 ` Linus Torvalds
2023-02-10 19:01 ` Andy Lutomirski
2023-02-10 19:18 ` Linus Torvalds
2023-02-10 19:27 ` Jeremy Allison
2023-02-10 19:42 ` Stefan Metzmacher
2023-02-10 19:42 ` Linus Torvalds
2023-02-10 19:54 ` Stefan Metzmacher
2023-02-10 19:29 ` Linus Torvalds
2023-02-13 9:07 ` Herbert Xu
2023-02-10 19:55 ` Andy Lutomirski
2023-02-10 20:27 ` Linus Torvalds
2023-02-10 20:32 ` Jens Axboe
2023-02-10 20:36 ` Linus Torvalds
2023-02-10 20:39 ` Jens Axboe
2023-02-10 20:44 ` Linus Torvalds
2023-02-10 20:50 ` Jens Axboe
2023-02-10 21:14 ` Andy Lutomirski
2023-02-10 21:27 ` Jens Axboe
2023-02-10 21:51 ` Jens Axboe
2023-02-10 22:08 ` Linus Torvalds [this message]
2023-02-10 22:16 ` Jens Axboe
2023-02-10 22:17 ` Linus Torvalds
2023-02-10 22:25 ` Jens Axboe
2023-02-10 22:35 ` Linus Torvalds
2023-02-10 22:51 ` Jens Axboe
2023-02-11 3:18 ` Ming Lei
2023-02-11 6:17 ` Ming Lei
2023-02-11 14:13 ` Jens Axboe
2023-02-11 15:05 ` Ming Lei
2023-02-11 15:33 ` Jens Axboe
2023-02-11 18:57 ` Linus Torvalds
2023-02-12 2:46 ` Jens Axboe
2023-02-10 4:47 ` Linus Torvalds
2023-02-10 6:19 ` Dave Chinner
2023-02-10 17:23 ` Linus Torvalds
2023-02-10 17:47 ` Linus Torvalds
2023-02-13 9:28 ` Herbert Xu
2023-02-10 22:41 ` David Laight
2023-02-10 22:51 ` Jens Axboe
2023-02-13 9:30 ` Herbert Xu
2023-02-13 9:25 ` Herbert Xu
2023-02-13 18:01 ` Andy Lutomirski
2023-02-14 1:22 ` Herbert Xu
2023-02-17 23:13 ` Andy Lutomirski
2023-02-20 4:54 ` Herbert Xu
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