On 3/13/20 8:01 PM, Andrii Nakryiko wrote:
On Fri, Mar 13, 2020 at 9:10 AM Jakub Sitnicki <jakub@xxxxxxxxxxxxxx> wrote:Andrii Nakryiko reports that sockmap_listen test suite is frequently failing due to accept() calls erroring out with EAGAIN: ./test_progs:connect_accept_thread:733: accept: Resource temporarily unavailable connect_accept_thread:FAIL:733 This is because we are using a non-blocking listening TCP socket to accept() connections without polling on the socket. While at first switching to blocking mode seems like the right thing to do, this could lead to test process blocking indefinitely in face of a network issue, like loopback interface being down, as Andrii pointed out. Hence, stick to non-blocking mode for TCP listening sockets but with polling for incoming connection for a limited time before giving up. Apply this approach to all socket I/O calls in the test suite that we expect to block indefinitely, that is accept() for TCP and recv() for UDP. Fixes: 44d28be2b8d4 ("selftests/bpf: Tests for sockmap/sockhash holding listening sockets") Reported-by: Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx> Signed-off-by: Jakub Sitnicki <jakub@xxxxxxxxxxxxxx>This looks good. Unfortunately can't repro the issue locally anymore. But once this gets into bpf-next and we update libbpf in Github, I'll enable sockmap_listen tests again and see if it's still flaky. Thanks for following up!
Ok, applied, thanks!
