Снова man libev-а

В 4983422a00a5cc0fdc461342c8f641e043c784f0 упоминал комментарии автора
касательно разных подсистем ОС. Но это был мой локальный man, далеко не
первой свежести. В новом есть речь про Linux AIO:

    This is another Linux train wreck of an event interface.

    If this backend works for you (as of this writing, it was very
    experimental), it is the best event interface available on
    Linux and might be well worth enabling it - if it isn't
    available in your kernel this will be detected and this backend
    will be skipped.

    This backend can batch oneshot requests and supports a user-
    space ring buffer to receive events. It also doesn't suffer
    from most of the design problems of epoll (such as not being
    able to remove event sources from the epoll set), and generally
    sounds too good to be true. Because, this being the Linux
    kernel, of course it suffers from a whole new set of
    limitations, forcing you to fall back to epoll, inheriting all
    its design issues.

    [...]

    Overall, it seems the Linux developers just don't want it to
    have a generic event handling mechanism other than "select" or
    "poll".

Про kqueue теперь написано не то, что на момент написания всё было
сломано, а то, что оно было сломано на момент создания этого backend:

    Kqueue deserves special mention, as at the time this backend
    was implemented, it was broken on all BSDs except NetBSD [...]

То бишь, всё стало ok теперь в BSD системах. А раздел посвящённый багам
GNU/Linux, Darwin и другим ОС так и остался, намекая что только в *BSD
всё более менее.