Re: [take24 0/6] kevent: Generic event handling mechanism.

Jeff Garzik
2006-11-20T21:46:27Z

Ulrich Drepper wrote:
> Evgeniy Polyakov wrote:
>> It is exactly how previous ring buffer (in mapped area though) was
>> implemented.
>
> Not any of those I saw. The one I looked at always started again at
> index 0 to fill the ring buffer. I'll wait for the next implementation.

I like the two-pointer ring buffer approach, one pointer for the
consumer and one for the producer.

> You don't want to have a channel like this. The userlevel code doesn't
> know which threads are waiting in the kernel on the event queue. And it

Agreed.

> You are still completely focused on AIO. We are talking here about a
> new generic event handling. It is not tied to AIO. We will add all

Agreed.

> As I said, relative timeouts are unable to cope with settimeofday calls
> or ntp adjustments. AIO is certainly usable in situations where
> timeouts are related to wall clock time.

I think we have lived with relative timeouts for so long, it would be
unusual to change now. select(2), poll(2), epoll_wait(2) all take
relative timeouts.

Jeff