From a6865576317f6249f3f83cf4c10ab56e627ee153 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Wed, 8 Mar 2023 22:02:44 -0800 Subject: [PATCH] selftests/bpf: Fix flaky fib_lookup test There is a report that fib_lookup test is flaky when running in parallel. A symptom of slowness or delay. An example: Testing IPv6 stale neigh set_lookup_params:PASS:inet_pton(IPV6_IFACE_ADDR) 0 nsec test_fib_lookup:PASS:bpf_prog_test_run_opts 0 nsec test_fib_lookup:FAIL:fib_lookup_ret unexpected fib_lookup_ret: actual 0 != expected 7 test_fib_lookup:FAIL:dmac not match unexpected dmac not match: actual 1 != expected 0 dmac expected 11:11:11:11:11:11 actual 00:00:00:00:00:00 [ Note that the "fib_lookup_ret unexpected fib_lookup_ret actual 0 ..." is reversed in terms of expected and actual value. Fixing in this patch also. ] One possibility is the testing stale neigh entry was marked dead by the gc (in neigh_periodic_work). The default gc_stale_time sysctl is 60s. This patch increases it to 15 mins. It also: - fixes the reversed arg (actual vs expected) in one of the ASSERT_EQ test - removes the nodad command arg when adding v4 neigh entry which currently has a warning. Fixes: 168de0233586 ("selftests/bpf: Add bpf_fib_lookup test") Reported-by: Alexei Starovoitov Signed-off-by: Martin KaFai Lau Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20230309060244.3242491-1-martin.lau@linux.dev --- tools/testing/selftests/bpf/prog_tests/fib_lookup.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/fib_lookup.c b/tools/testing/selftests/bpf/prog_tests/fib_lookup.c index 429393caf612..a1e712105811 100644 --- a/tools/testing/selftests/bpf/prog_tests/fib_lookup.c +++ b/tools/testing/selftests/bpf/prog_tests/fib_lookup.c @@ -54,11 +54,19 @@ static int setup_netns(void) SYS(fail, "ip link add veth1 type veth peer name veth2"); SYS(fail, "ip link set dev veth1 up"); + err = write_sysctl("/proc/sys/net/ipv4/neigh/veth1/gc_stale_time", "900"); + if (!ASSERT_OK(err, "write_sysctl(net.ipv4.neigh.veth1.gc_stale_time)")) + goto fail; + + err = write_sysctl("/proc/sys/net/ipv6/neigh/veth1/gc_stale_time", "900"); + if (!ASSERT_OK(err, "write_sysctl(net.ipv6.neigh.veth1.gc_stale_time)")) + goto fail; + SYS(fail, "ip addr add %s/64 dev veth1 nodad", IPV6_IFACE_ADDR); SYS(fail, "ip neigh add %s dev veth1 nud failed", IPV6_NUD_FAILED_ADDR); SYS(fail, "ip neigh add %s dev veth1 lladdr %s nud stale", IPV6_NUD_STALE_ADDR, DMAC); - SYS(fail, "ip addr add %s/24 dev veth1 nodad", IPV4_IFACE_ADDR); + SYS(fail, "ip addr add %s/24 dev veth1", IPV4_IFACE_ADDR); SYS(fail, "ip neigh add %s dev veth1 nud failed", IPV4_NUD_FAILED_ADDR); SYS(fail, "ip neigh add %s dev veth1 lladdr %s nud stale", IPV4_NUD_STALE_ADDR, DMAC); @@ -158,7 +166,7 @@ void test_fib_lookup(void) if (!ASSERT_OK(err, "bpf_prog_test_run_opts")) continue; - ASSERT_EQ(tests[i].expected_ret, skel->bss->fib_lookup_ret, + ASSERT_EQ(skel->bss->fib_lookup_ret, tests[i].expected_ret, "fib_lookup_ret"); ret = memcmp(tests[i].dmac, fib_params->dmac, sizeof(tests[i].dmac)); -- 2.11.0