Re: [PATCH mptcp-net] selftests: mptcp: drop nanoseconds width specifier

[Matthieu Baerts <matttbe@kernel.org>]

Hello,

On 15/05/2026 04:11, Matthieu Baerts (NGI0) wrote:
> Using the format specifier +%s%3N with GNU date is honoured, and only
> prints 3 digits of the nanoseconds portion of the seconds since epoch,
> which corresponds to the milliseconds.
> 
> The uutils implementation of date currently does not honour this, and
> always prints all 9 digits. This is a known issue [1], but can be worked
> around by adapting this test to use nanoseconds instead of microseconds,
> and then divide it by 1e6.
> 
> This fix is similar to what has been done on systemd side [2].

I suggest applying this patch, and sending to netdev-net, not to block
those using uutils, e.g. on Ubuntu 26.04.

I will apply a small change, see below.

(...)

> diff --git a/tools/testing/selftests/net/mptcp/mptcp_lib.sh b/tools/testing/selftests/net/mptcp/mptcp_lib.sh
> index 989a5975dcea..9d3efbfb3015 100644
> --- a/tools/testing/selftests/net/mptcp/mptcp_lib.sh
> +++ b/tools/testing/selftests/net/mptcp/mptcp_lib.sh
> @@ -236,7 +236,7 @@ mptcp_lib_kversion_ge() {
>  }
>  
>  mptcp_lib_subtests_last_ts_reset() {
> -	MPTCP_LIB_SUBTESTS_LAST_TS_MS="$(date +%s%3N)"
> +	MPTCP_LIB_SUBTESTS_LAST_TS_MS="$(date +%s%N)"

The suffix should then be _NS instead of _MS.

Cheers,
Matt
-- 
Sponsored by the NGI0 Core fund.