Re: [PATCH v3 0/1] pipe: only enable the extra wake_up(rd_wait) for edge-triggered consumers

Linus Torvalds <[email protected]>
Newsgroups org.kernel.vger.linux-fsdevel,org.kernel.vger.io-uring,org.kernel.vger.linux-kernel
Message-ID <CAHk-=wi7EccGaeo2Q5mdcvcQJ8VX7tcJWW2fHkg6vfmHGGX8AA@mail.gmail.com>
On Thu, 30 Jul 2026 at 07:12, Oleg Nesterov <[email protected]> wrote:
>
> Let me repeat, I do not think this patch can improve performance. In fact
> I only hope that none of (micro)benchmarks will suffer, they are often
> very sensitive to any changes in pipe.c

I like this patch mostly for the renaming, not because I think it
matters. I think "poll usage" was a mistake in naming and doesn't
explain the issue. That said, I'd go even further, and make it clear
that it's not about "poll" itself - which is fine, it's about "epoll",
which has that broken crazy bug where it calls something "edge
triggered" but then actually wants effectively level-triggered
behavior - wakeups when nothing actually changed, which is the
*opposite* of an edge.

Pure garbage.

So the real name should be something like "epoll_pseudo_edgetrigger".
Because "et" isn't really helpful either.

             Linus
lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.