Re: [PATCH] 2.5.46: epoll ep_insert doesn't wake waiters if events exist

[Davide Libenzi <davidel@xmailserver.org>]

On Fri, 8 Nov 2002, Mark Hamblin wrote:

> Looking at the documentation at
> http://www.xmailserver.org/linux-patches/epoll_wait.txt, I noticed that the
> description for epoll_wait states:  "On success, epoll_wait(2) returns the
> number of file descriptors ready for the requested I/O."  My question is if
> I have, for example, 1000 sockets registered with epoll and 100 of them have
> received data and I call epoll_wait with max_events set to 10, will
> epoll_wait return 10 or 100?  Furthermore, does the edge-triggered nature of
> epoll "eat the edge" for the other 90 sockets even though they didn't get
> returned?  Finally, if those 10 sockets get more data before I call
> epoll_wait with max_events = 10 again, will those same 10 sockets get
> returned?

epoll will return 10 and the remaining 90 will remain available for future
epoll_wait() calls. The last question will trigger a change in my code,
from list_add() to list_add_tail(). Since I don't want to stress Linus
with 24590 patches, I'll wait for 2.5.47 to merge the new code ...



- Davide