Re: [PATCH v3 1/1] pipe: only enable the extra wake_up(rd_wait) for edge-triggered consumers

Breno Leitao <[email protected]> Fri, 31 Jul 2026 01:27:03 -0700
Newsgroups org.kernel.vger.io-uring,org.kernel.vger.linux-fsdevel,org.kernel.vger.linux-kernel
Message-ID <[email protected]>
On Thu, Jul 30, 2026 at 10:01:56PM +0200, Mateusz Guzik wrote:
> On Thu, Jul 30, 2026 at 4:38 PM Oleg Nesterov <[email protected]> wrote:
> > What exactly do you think the comment should say? I agree with anything in
> > advance. I thought that "edge-triggered" provides enough info, but I would
> > be happy to improve the docs.
> >
> 
> how about: There is userspace depending on the extra wake up, see
> commit 3a34b13a88caeb28 ("pipe: make pipe writes always wake up
> readers") for details.
> 
> or whatever else which refers to the commit, no need for anything
> fancy. the current commentary is definitely lame.

Agreed. The rationale was non-obvious without digging into commit
3a34b13a88caeb28 ("pipe: make pipe writes always wake up readers").

Having an explicit reference in the comment would clarify why the
unconditional wakeup exists, rather than leaving it to appear as a
potential weirdness without clear comment.