From: Petr Machata petrm@nvidia.com

[ Upstream commit dda7f4fa55839baeb72ae040aeaf9ccf89d3e416 ]

The intention behind this test is to make sure that qdisc limit is correctly projected to the HW. However, first, due to rounding in the qdisc, and then in the driver, the number cannot actually be accurate. And second, the approach to testing this is to oversubscribe the port with traffic generated on the same switch. The actual backlog size therefore fluctuates.

In practice, this test proved to be noisier than the rest, and spuriously fails every now and then. Increase the tolerance to 10 % to avoid these issues.

Signed-off-by: Petr Machata petrm@nvidia.com Acked-by: Jiri Pirko jiri@nvidia.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- tools/testing/selftests/drivers/net/mlxsw/sch_red_core.sh | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/drivers/net/mlxsw/sch_red_core.sh b/tools/testing/selftests/drivers/net/mlxsw/sch_red_core.sh index b0cb1aaffdda..33ddd01689be 100644 --- a/tools/testing/selftests/drivers/net/mlxsw/sch_red_core.sh +++ b/tools/testing/selftests/drivers/net/mlxsw/sch_red_core.sh @@ -507,8 +507,8 @@ do_red_test() check_err $? "backlog $backlog / $limit Got $pct% marked packets, expected == 0." local diff=$((limit - backlog)) pct=$((100 * diff / limit)) - ((0 <= pct && pct <= 5)) - check_err $? "backlog $backlog / $limit expected <= 5% distance" + ((0 <= pct && pct <= 10)) + check_err $? "backlog $backlog / $limit expected <= 10% distance" log_test "TC $((vlan - 10)): RED backlog > limit"

stop_traffic