From: Kal Conley <kal.conley@xxxxxxxxxxx> [ Upstream commit 68e7322142f5e731af222892d384d311835db0f1 ] Fix flaky STATS_RX_DROPPED test. The receiver calls getsockopt after receiving the last (valid) packet which is not the final packet sent in the test (valid and invalid packets are sent in alternating fashion with the final packet being invalid). Since the last packet may or may not have been dropped already, both outcomes must be allowed. This issue could also be fixed by making sure the last packet sent is valid. This alternative is left as an exercise to the reader (or the benevolent maintainers of this file). This problem was quite visible on certain setups. On one machine this failure was observed 50% of the time. Also, remove a redundant assignment of pkt_stream->nb_pkts. This field is already initialized by __pkt_stream_alloc. Fixes: 27e934bec35b ("selftests: xsk: make stat tests not spin on getsockopt") Signed-off-by: Kal Conley <kal.conley@xxxxxxxxxxx> Acked-by: Magnus Karlsson <magnus.karlsson@xxxxxxxxx> Link: https://lore.kernel.org/r/20230403120400.31018-1-kal.conley@xxxxxxxxxxx Signed-off-by: Martin KaFai Lau <martin.lau@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- tools/testing/selftests/bpf/xskxceiver.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/bpf/xskxceiver.c b/tools/testing/selftests/bpf/xskxceiver.c index 2290982758961..b74dddf6bbbe5 100644 --- a/tools/testing/selftests/bpf/xskxceiver.c +++ b/tools/testing/selftests/bpf/xskxceiver.c @@ -649,7 +649,6 @@ static struct pkt_stream *pkt_stream_generate(struct xsk_umem_info *umem, u32 nb if (!pkt_stream) exit_with_error(ENOMEM); - pkt_stream->nb_pkts = nb_pkts; for (i = 0; i < nb_pkts; i++) { pkt_set(umem, &pkt_stream->pkts[i], (i % umem->num_frames) * umem->frame_size, pkt_len); @@ -1142,7 +1141,14 @@ static int validate_rx_dropped(struct ifobject *ifobject) if (err) return TEST_FAILURE; - if (stats.rx_dropped == ifobject->pkt_stream->nb_pkts / 2) + /* The receiver calls getsockopt after receiving the last (valid) + * packet which is not the final packet sent in this test (valid and + * invalid packets are sent in alternating fashion with the final + * packet being invalid). Since the last packet may or may not have + * been dropped already, both outcomes must be allowed. + */ + if (stats.rx_dropped == ifobject->pkt_stream->nb_pkts / 2 || + stats.rx_dropped == ifobject->pkt_stream->nb_pkts / 2 - 1) return TEST_PASS; return TEST_FAILURE; -- 2.39.2