diff mbox series

[net-next,2/5] selftests: mlxsw: sch_red_core: Increase backlog size tolerance

Message ID f54950df2a8fcba46c3ddc1053376352fa2e592b.1728316370.git.petrm@nvidia.com (mailing list archive)
State Accepted
Commit 8fb5b60734564473c72ca85d617cd685738948f0
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 success total: 0 errors, 0 warnings, 0 checks, 13 lines checked
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 
Backlog fluctuates on Spectrum-4 much more than on <4. In practice we can
sample queue depth values going from about -12% to about +7% of the
configured RED limit. The test which checks the queue size has a limit of
+-10%, and as a result often fails. We attempted to fix the issue by
busywaiting for several seconds hoping to get within the bounds, but that
still proved to be too noisy (or the wait time would be impractically
long). Unfortunately we have to bump the value tolerance from 10% to 15%,
which in this patch do.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Amit Cohen <amcohen@nvidia.com>
---
 tools/testing/selftests/drivers/net/mlxsw/sch_red_core.sh | 5 +++--
 1 file changed, 3 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 299e06a5808c..a25a15eb6d31 100644
--- a/tools/testing/selftests/drivers/net/mlxsw/sch_red_core.sh
+++ b/tools/testing/selftests/drivers/net/mlxsw/sch_red_core.sh
@@ -532,10 +532,11 @@  do_red_test()
 	check_fail $? "Traffic went into backlog instead of being early-dropped"
 	pct=$(check_marking get_nmarked $vlan "== 0")
 	check_err $? "backlog $backlog / $limit Got $pct% marked packets, expected == 0."
+	backlog=$(get_qdisc_backlog $vlan)
 	local diff=$((limit - backlog))
 	pct=$((100 * diff / limit))
-	((-10 <= pct && pct <= 10))
-	check_err $? "backlog $backlog / $limit expected <= 10% distance"
+	((-15 <= pct && pct <= 15))
+	check_err $? "backlog $backlog / $limit expected <= 15% distance"
 	log_test "TC $((vlan - 10)): RED backlog > limit"
 
 	stop_traffic