On 12/4/19 11:53 AM, Thadeu Lima de Souza Cascardo wrote: > When using fragments with size 8 and payload larger than 8000, the backlog > might fill up and packets will be dropped, causing the test to fail. This > happens often enough when conntrack is on during the IPv6 test. > > As the larger payload in the test is 10000, using a backlog of 1250 allow > the test to run repeatedly without failure. At least a 1000 runs were > possible with no failures, when usually less than 50 runs were good enough > for showing a failure. > > As netdev_max_backlog is not a pernet setting, this sets the backlog to > 1000 during exit to prevent disturbing following tests. > Hmmm... I would prefer not changing a global setting like that. This is going to be flaky since we often run tests in parallel (using different netns) What about adding a small delay after each sent packet ? diff --git a/tools/testing/selftests/net/ip_defrag.c b/tools/testing/selftests/net/ip_defrag.c index c0c9ecb891e1d78585e0db95fd8783be31bc563a..24d0723d2e7e9b94c3e365ee2ee30e9445deafa8 100644 --- a/tools/testing/selftests/net/ip_defrag.c +++ b/tools/testing/selftests/net/ip_defrag.c @@ -198,6 +198,7 @@ static void send_fragment(int fd_raw, struct sockaddr *addr, socklen_t alen, error(1, 0, "send_fragment: %d vs %d", res, frag_len); frag_counter++; + usleep(1000); } static void send_udp_frags(int fd_raw, struct sockaddr *addr,