On Fri, Aug 02, 2024 at 10:23:30AM +0100, Dmitry Safonov via B4 Relay wrote: > From: Dmitry Safonov <0x7f454c46@xxxxxxxxx> > > On tests that are expecting failure the timeout value is > TEST_RETRANSMIT_SEC == 1 second. Which is big enough for most of devices > under tests. But on a particularly slow machine/VM, 1 second might be > not enough for another thread to be scheduled and attempt to connect(). > It is not a problem for tests that expect connect() to succeed as > the timeout value for them (TEST_TIMEOUT_SEC) is intentionally bigger. > > One obvious way to solve this would be to increase TEST_RETRANSMIT_SEC. > But as all tests would increase the timeouts, that's going to sum up. > > But here is less obvious way that keeps timeouts for expected connect() > failures low: just synchronize the two threads, which will assure that > before counter checks the other thread got a chance to run and timeout > on connect(). The expected increase of the related counter for listen() > socket will yet test the expected failure. > > Never happens on my machine, but I suppose the majority of netdev's > connect-deny-* flakes [1] are caused by this. > > Fixes: Hi Dmitry, I realise it probably wasn't intended to be a fixes tag, but it turns out to be an invalid one. Could you express this in a different way? > > # selftests: net/tcp_ao: connect-deny_ipv6 > > # 1..21 > > # # 462[lib/setup.c:243] rand seed 1720905426 > > # TAP version 13 > > # ok 1 Non-AO server + AO client > > # not ok 2 Non-AO server + AO client: TCPAOKeyNotFound counter did not increase: 0 <= 0 > > # ok 3 AO server + Non-AO client > > # ok 4 AO server + Non-AO client: counter TCPAORequired increased 0 => 1 > ... > > [1]: https://netdev-3.bots.linux.dev/vmksft-tcp-ao/results/681741/6-connect-deny-ipv6/stdout > Signed-off-by: Dmitry Safonov <0x7f454c46@xxxxxxxxx> ...
