From: Oleg Nesterov <oleg@redhat.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Christian Brauner <brauner@kernel.org>,
Jeff Layton <jlayton@kernel.org>,
David Howells <dhowells@redhat.com>,
"Gautham R. Shenoy" <gautham.shenoy@amd.com>,
K Prateek Nayak <kprateek.nayak@amd.com>,
Mateusz Guzik <mjguzik@gmail.com>,
Neeraj Upadhyay <Neeraj.Upadhyay@amd.com>,
Oliver Sang <oliver.sang@intel.com>,
Swapnil Sapkal <swapnil.sapkal@amd.com>,
WangYuli <wangyuli@uniontech.com>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] pipe: change pipe_write() to never add a zero-sized buffer
Date: Sun, 9 Feb 2025 20:15:11 +0100 [thread overview]
Message-ID: <20250209191510.GB27435@redhat.com> (raw)
In-Reply-To: <CAHk-=wihBAcJLiC9dxj1M8AKHpdvrRneNk3=s-Rt-Hv5ikqo4g@mail.gmail.com>
On 02/09, Linus Torvalds wrote:
>
> On Sun, 9 Feb 2025 at 10:45, Oleg Nesterov <oleg@redhat.com> wrote:
> >
> > Again, lets look eat_empty_buffer().
> >
> > The comment says "maybe it's empty" but how/why can this happen ?
>
> WHY DO YOU CARE?
Because it looks unclear/confusing, and I think it can confuse other
readers of this code. Especially after 1/2.
> So here's the deal: either you
...
> (b) you DON'T convince yourself that that is true, and you leave
> eat_empty_buffer() alone.
Yes, I failed to convince myself that fs/splice.c can never add an
empty bufer. Although it seems to me it should not.
> In contrast, the "eat_empty_buffer()" case just saying "if it's an
> empty buffer, it doesn't satisfy my needs, so I'll just release the
> empty buffer and go on".
... without wakeup_pipe_writers().
OK, nevermind, I see your point even if I do not 100% agree.
I'll send v2 without WARN_ON() and without 2/2.
Oleg.
next prev parent reply other threads:[~2025-02-09 19:15 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-09 15:07 [PATCH 0/2] pipe: change pipe_write() to never add a zero-sized buffer Oleg Nesterov
2025-02-09 15:07 ` [PATCH 1/2] " Oleg Nesterov
2025-02-09 17:26 ` Linus Torvalds
2025-02-09 18:02 ` Oleg Nesterov
2025-02-09 18:17 ` Linus Torvalds
2025-02-09 18:44 ` Oleg Nesterov
2025-02-09 18:52 ` Linus Torvalds
2025-02-09 19:15 ` Oleg Nesterov [this message]
2025-02-09 23:39 ` K Prateek Nayak
2025-02-10 17:22 ` Oleg Nesterov
2025-02-10 17:37 ` Linus Torvalds
2025-02-10 18:36 ` Oleg Nesterov
2025-02-11 3:59 ` K Prateek Nayak
2025-02-09 15:08 ` [PATCH 2/2] splice: add some pipe_buf_assert_len() checks Oleg Nesterov
2025-02-10 11:40 ` [PATCH v2 1/1] pipe: change pipe_write() to never add a zero-sized buffer Oleg Nesterov
2025-02-10 12:52 ` [PATCH 0/2] " Christian Brauner
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