Re: [patch 2/2] fix compiler warning and optimize the non-blocking path

[Andrew Morton <akpm@linux-foundation.org>]

On Sat, 15 Jan 2011 11:43:45 -0800 (PST)
Davide Libenzi <davidel@xmailserver.org> wrote:

> +/**
> + * ep_poll - Retrieves ready events, and delivers them to the caller supplied
> + *           event buffer.
> + *
> + * @ep: Pointer to the eventpoll context.
> + * @events: Pointer to the userspace buffer where the ready events should be
> + *          stored.
> + * @maxevents: Size (in terms of number of events) of the caller event buffer.
> + * @timeout: Maximum timeout for the ready events fetch operation, in
> + *           milliseconds. If the @timeout is zero, the function will not block,
> + *           while if the @timeout is less than zero, the function will block
> + *           until at least one event has been retrieved (or an error
> + *           occurred).

Ah, that's what timeout<0 means.

My `man epoll_wait' says "a timeout of -1 makes epoll_wait() wait
indefinitely", whereas the implementation accepts any -ve value.

So we lost the ability to later make -[2..MAX_INT] meaningful in some
new way.  Oh well.

> + * Returns: Returns the number of ready events which have been fetched, or an
> + *          error code, in case of error.
> + */