Re: [PATCH net] selftests: net: bump default cmd() timeout to 20 seconds

[Nimrod Oren <noren@nvidia.com>]

On 30/06/2026 2:33, Jakub Kicinski wrote:
> We always used 5 sec as the default command timeout. But soon after
> it was introduced, David effectively made us ignore the timeout
> (it was passed to process.communicate() as the wrong argument).
> Gal recently fixed that, but turns out the 5 sec is not enough
> for a lot of tests and setups. The fix regressed regressions.
> 
> In particular running reconfig commands (e.g. XDP attach) on mlx5
> with 32 rings and 9k MTU, on a heavily-debug-enabled kernel takes
> more than 5 sec. The XDP installation command will time out after
> 5 sec but since the sleeps in the kernel are non interruptible
> the command finishes anyway, leaving the XDP program attached,
> but with non-zero exit code. defer()ed cleanups are not installed,
> breaking the environment for subsequent tests.
> 
> Since "install XDP" is a pretty normal command a "point fix"
> does not seem appropriate. 32 rings is a fairly reasonable
> config, too, so we should just increase the timeout to 20 sec.
> 
> There's no real reason behind the value of 20.
> 
> Fixes: 1cf270424218 ("net: selftest: add test for netdev netlink queue-get API")
> Fixes: f0bd19316663 ("selftests: net: fix timeout passed as positional argument to communicate()")
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
> ---
> CC: shuah@kernel.org
> CC: petrm@nvidia.com
> CC: leitao@debian.org
> CC: dw@davidwei.uk
> CC: noren@nvidia.com
> CC: gal@nvidia.com
> CC: linux-kselftest@vger.kernel.org
> ---
>  tools/testing/selftests/net/lib/py/utils.py | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 

Reviewed-by: Nimrod Oren <noren@nvidia.com>

> diff --git a/tools/testing/selftests/net/lib/py/utils.py b/tools/testing/selftests/net/lib/py/utils.py
> index 308c91833239..9b40049e2dbb 100644
> --- a/tools/testing/selftests/net/lib/py/utils.py
> +++ b/tools/testing/selftests/net/lib/py/utils.py
> @@ -44,7 +44,7 @@ import time
>      Use bkg() instead to run a command in the background.
>      """
>      def __init__(self, comm, shell=None, fail=True, expect_fail=False, ns=None,
> -                 background=False, host=None, timeout=5, ksft_ready=None,
> +                 background=False, host=None, timeout=20, ksft_ready=None,
>                   ksft_wait=None):
>          if ns:
>              if hasattr(ns, 'user_ns_path'):
> @@ -113,7 +113,7 @@ import time
>  
>          return stdout, stderr
>  
> -    def process(self, terminate=True, fail=None, expect_fail=False, timeout=5):
> +    def process(self, terminate=True, fail=None, expect_fail=False, timeout=20):
>          if fail is None:
>              fail = not terminate
>