On Thu, Jul 10, 2025 at 07:53:12AM -0700, Jakub Kicinski wrote:
> The rtnetlink test for preferred lifetime of an address is quite flaky.
> Problems started around the 6.16 merge window in May. The test fails
> with:
>
> FAIL: preferred_lft addresses remaining
>
> and unlike most of our flakes this one fails on the "normal" kernel
> builds, not the builds with kernel/configs/debug.config. I suspect
> the flakes may be related to power saving, since the expirations
> run from a "power efficient" workqueue. Adding a short sleep seems
> to decrease the flakes by 8x but they still happen. With this
> patch in place we get a flake every couple of weeks, not every
> couple of days. Better ideas welcome..
>
> Signed-off-by: Jakub Kicinski <k...@kernel.org>
> ---
> CC: liuhang...@gmail.com
> CC: sh...@kernel.org
> CC: linux-kselftest@vger.kernel.org
> ---
> tools/testing/selftests/net/rtnetlink.sh | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/tools/testing/selftests/net/rtnetlink.sh
> b/tools/testing/selftests/net/rtnetlink.sh
> index 2e8243a65b50..b9e1497ea27a 100755
> --- a/tools/testing/selftests/net/rtnetlink.sh
> +++ b/tools/testing/selftests/net/rtnetlink.sh
> @@ -299,6 +299,11 @@ kci_test_addrlft()
> done
>
> sleep 5
> + # Schedule out for a bit, address GC runs from the power efficient WQ
> + # if the long sleep above has put the whole system into sleep state
> + # the WQ may have not had a chance to run.
> + sleep 0.1
> +
How about use slowwait to check if the address still exists. e.g.
check_addr_not_exist()
{
dev=$1
addr=$2
if ip addr show dev $dev | grep -q $addr; then
return 1
else
return 0
}
slowwait 5 check_addr_not_exist "$devdummy" "10.23.11."
> run_cmd_grep_fail "10.23.11." ip addr show dev "$devdummy"
> if [ $? -eq 0 ]; then
> check_err 1
> --
> 2.50.0
>
