diff mbox series

[net-next,5/6] selftests: mlxsw: Increase the tolerance of backlog buildup

Message ID d53eff3b2ec168f350195e8325f867bd87ad65e4.1619179926.git.petrm@nvidia.com (mailing list archive)
State Accepted
Commit dda7f4fa55839baeb72ae040aeaf9ccf89d3e416
Delegated to: Netdev Maintainers
Headers show
Series selftests: mlxsw: Fixes | expand

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Commit Message

Petr Machata April 23, 2021, 12:19 p.m. UTC 
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>
---
 tools/testing/selftests/drivers/net/mlxsw/sch_red_core.sh | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff mbox series

Patch

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