diff mbox series

[net-next,4/5] selftests: mlxsw: sch_red_core: Send more packets for drop tests

Message ID abc869b9f6003d400d6293ddd5edb2f4517f44d5.1728316370.git.petrm@nvidia.com (mailing list archive)
State Accepted
Commit 7049166e51bc2b854935eda72f7fb8c3f4492f6f
Delegated to: Netdev Maintainers
Headers show
Series selftests: mlxsw: Stabilize RED tests | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 5 this patch: 5
netdev/build_tools success Errors and warnings before: 0 (+2) this patch: 0 (+2)
netdev/cc_maintainers success CCed 8 of 8 maintainers
netdev/build_clang success Errors and warnings before: 5 this patch: 5
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success net selftest script(s) already in Makefile
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 3 this patch: 3
netdev/checkpatch warning WARNING: line length of 81 exceeds 80 columns WARNING: line length of 93 exceeds 80 columns
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-10-08--00-00 (tests: 773)

Commit Message

Petr Machata Oct. 7, 2024, 4:26 p.m. UTC 
This test works by injecting into a port with a maxed-out queue a couple
packets and checks if a corresponding number of packets were dropped. This
has worked well on Spectrum<4, but on Spectrum-4 it has been noisy. This
is in line with the observation that on Spectrum-4, queue size tends to
fluctuate more. A handful of packets could then still be accepted to the
queue even though it was nominally full just recently.

In order to accommodate this behavior, send many more packets. The buffer
can fit N extra packets, but not N% packets. This therefore allows us to
set wider absolute margins, while actually narrowing them relatively.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
---
 .../selftests/drivers/net/mlxsw/sch_red_core.sh  | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 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 b1ff395b3880..316444389c4e 100644
--- a/tools/testing/selftests/drivers/net/mlxsw/sch_red_core.sh
+++ b/tools/testing/selftests/drivers/net/mlxsw/sch_red_core.sh
@@ -653,20 +653,22 @@  do_drop_test()
 	build_backlog $vlan $((3 * limit / 2)) udp >/dev/null
 
 	base=$($fetch_counter)
-	send_packets $vlan udp 11
+	send_packets $vlan udp 100
 
-	now=$(busywait 1100 until_counter_is ">= $((base + 10))" $fetch_counter)
-	check_err $? "Dropped packets not observed: 11 expected, $((now - base)) seen"
+	now=$(busywait 1100 until_counter_is ">= $((base + 95))" $fetch_counter)
+	check_err $? "${trigger}ped packets not observed: 100 expected, $((now - base)) seen"
 
 	# When no extra traffic is injected, there should be no mirroring.
-	busywait 1100 until_counter_is ">= $((base + 20))" $fetch_counter >/dev/null
+	busywait 1100 until_counter_is ">= $((base + 110))" \
+		 $fetch_counter >/dev/null
 	check_fail $? "Spurious packets observed"
 
 	# When the rule is uninstalled, there should be no mirroring.
 	qevent_rule_uninstall_$subtest
-	send_packets $vlan udp 11
-	busywait 1100 until_counter_is ">= $((base + 20))" $fetch_counter >/dev/null
-	check_fail $? "Spurious packets observed after uninstall"
+	send_packets $vlan udp 100
+	now=$(busywait 1100 until_counter_is ">= $((base + 110))" \
+		       $fetch_counter)
+	check_fail $? "$((now - base)) spurious packets observed after uninstall"
 
 	log_test "TC $((vlan - 10)): ${trigger}ped packets $subtest'd"