Re: [PATCH v3 0/1] pipe: only enable the extra wake_up(rd_wait) for edge-triggered consumers
Linus Torvalds <[email protected]> Thu, 30 Jul 2026 09:36:35 -0700
| Newsgroups | org.kernel.vger.io-uring,org.kernel.vger.linux-fsdevel,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