On Wed, 2016-08-24 at 11:22 +0300, Dan Akunis wrote: > When select wakes up on a UDP socket, user is expecting to get data. Getting > 0 from recvfrom() or whatever read function she uses, is a wrong attitude. > I agree with David. > > The unit test that expects select to wake up is wrong and should be changed. >
Please do not top post on netdev mailing list. Program is fine and wont be changed to work around a kernel bug. We definitely can send and receive UDP messages with 0 payload. So select() should unblock when one such frame is received, otherwise you could fill up the receive queue with a lot of frames like that and when SO_RCVBUF limit is reached, block future messages. UDP is a datagram protocol. Bug fix is merged : https://git.kernel.org/cgit/linux/kernel/git/davem/net.git/commit/?id=e83c6744e81abc93a20d0eb3b7f504a176a6126a
