Re: UDP recvmsg blocks after select(), 2.6 bug?

Alan Cox
2004-10-07T14:52:45Z

On Iau, 2004-10-07 at 15:07, Martijn Sipkema wrote:
> > Much can change between the select() and recvmsg - things outside of
> > kernel control too, and it's long been known.
>
> There is no change; the current implementation just checks the validity of
> the data in the recvmsg() call and not during select().

The accept one is documented by Stevens and well known. In the UDP case
currently we could get precise behaviour - by halving performance of UDP
applications like video streaming. We probably don't want to because we
can respond intelligently to OOM situations by freeing the queue if we
don't enforce such a silly rule.