diff options
| author | Ido Schimmel <idosch@nvidia.com> | 2025-07-31 14:09:14 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-08-01 13:51:41 -0700 |
| commit | f8fded7536a9350ce849f21eee124d66056aa54c (patch) | |
| tree | 3b6982c1baee2f4938cbe940d071a8f1e59e7f6b | |
| parent | 01051012887329ea78eaca19b1d2eac4c9f601b5 (diff) | |
selftests: net: Fix flaky neighbor garbage collection test
The purpose of the "Periodic garbage collection" test case is to make
sure that "extern_valid" neighbors are not flushed during periodic
garbage collection, unlike regular neighbor entries.
The test case is currently doing the following:
1. Changing the base reachable time to 10 seconds so that periodic
garbage collection will run every 5 seconds.
2. Changing the garbage collection stale time to 5 seconds so that
neighbors that have not been used in the last 5 seconds will be
considered for removal.
3. Waiting for the base reachable time change to take effect.
4. Adding an "extern_valid" neighbor, a non-"extern_valid" neighbor and
a bunch of other neighbors so that the threshold ("thresh1") will be
crossed and stale neighbors will be flushed during garbage
collection.
5. Waiting for 10 seconds to give garbage collection a chance to run.
6. Checking that the "extern_valid" neighbor was not flushed and that
the non-"extern_valid" neighbor was flushed.
The test sometimes fails in the netdev CI because the non-"extern_valid"
neighbor was not flushed. I am unable to reproduce this locally, but my
theory that since we do not know exactly when the periodic garbage
collection runs, it is possible for it to run at a time when the
non-"extern_valid" neighbor is still not considered stale.
Fix by moving the addition of the two neighbors before step 3 and by
reducing the garbage collection stale time to 1 second, to ensure that
both neighbors are considered stale when garbage collection runs.
Fixes: 171f2ee31a42 ("selftests: net: Add a selftest for externally validated neighbor entries")
Reported-by: Jakub Kicinski <kuba@kernel.org>
Closes: https://lore.kernel.org/netdev/20250728093504.4ebbd73c@kernel.org/
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20250731110914.506890-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rwxr-xr-x | tools/testing/selftests/net/test_neigh.sh | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/tools/testing/selftests/net/test_neigh.sh b/tools/testing/selftests/net/test_neigh.sh index 388056472b5b..7c594bf6ead0 100755 --- a/tools/testing/selftests/net/test_neigh.sh +++ b/tools/testing/selftests/net/test_neigh.sh @@ -289,11 +289,11 @@ extern_valid_common() orig_base_reachable=$(ip -j ntable show name "$tbl_name" | jq '.[] | select(has("thresh1")) | .["base_reachable"]') run_cmd "ip ntable change name $tbl_name thresh1 10 base_reachable 10000" orig_gc_stale=$(ip -n "$ns1" -j ntable show name "$tbl_name" dev veth0 | jq '.[]["gc_stale"]') - run_cmd "ip -n $ns1 ntable change name $tbl_name dev veth0 gc_stale 5000" - # Wait orig_base_reachable/2 for the new interval to take effect. - run_cmd "sleep $(((orig_base_reachable / 1000) / 2 + 2))" + run_cmd "ip -n $ns1 ntable change name $tbl_name dev veth0 gc_stale 1000" run_cmd "ip -n $ns1 neigh add $ip_addr lladdr $mac nud stale dev veth0 extern_valid" run_cmd "ip -n $ns1 neigh add ${subnet}3 lladdr $mac nud stale dev veth0" + # Wait orig_base_reachable/2 for the new interval to take effect. + run_cmd "sleep $(((orig_base_reachable / 1000) / 2 + 2))" for i in {1..20}; do run_cmd "ip -n $ns1 neigh add ${subnet}$((i + 4)) nud none dev veth0" done |