Re: [patch, rfc] lt-epoll ( level triggered epoll ) ...

Davide Libenzi (davidel@xmailserver.org)
Fri, 14 Mar 2003 08:53:55 -0800 (PST)


On Fri, 14 Mar 2003, Valentin Nechayev wrote:

> Tue, Mar 11, 2003 at 14:27:50, jamie wrote about "Re: [patch, rfc] lt-epoll ( level triggered epoll ) ...":
>
> > Actually I think _this_ is cleanest: A three-way flag per registered
> > fd interest saying whether to:
> >
> > 1. Report 0->1 edges for this interest. (Initial 1 counts as an event).
> > 2. Continually report 1 levels for this interest.
> > 3. One-shot, report the first time 1 is noted and unregister.
> >
> > ET poll is equivalent to 1. LT poll is equivalent to 2. dnotify's
> > one-shot mode is equivalent to 3.
>
> kqueue can do all three variants (1st with EV_CLEAR, 3rd with EV_ONESHOT).
>
> So, result of this whole epoll work is trivially predictable - Linux will have
> analog of "overbloated" and "poorly designed" kqueue, but more poor
> and with incompatible interface, adding its own stone to hell of
> different APIs. Congratulations.

See, this is a free world, and I very much respect your opinion. On the
other side you might want to actually *read* the kqueue man page and find
out of its 24590 flags, where 99% of its users will use only 1% of its
functionality. Talking about overbloating. You might also want to know
that quite a few kqueue users currently running on your favourite OS, are
moving to Linux+epoll. The reason is still unclear to me, but I can leave
you to discover it as exercise.

> Linus was true: Linux is just for fun, not for work.

You're right here. We're having *a lot* of fun listening this kind of
statements.

- Davide

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