Re: [PATCH net-next v7 0/3] selftests: drv-net: convert so_txtime to drv-net

[Willem de Bruijn <willemdebruijn.kernel@gmail.com>]

Jakub Kicinski wrote:
> On Mon,  4 May 2026 13:38:31 -0400 Willem de Bruijn wrote:
> > From: Willem de Bruijn <willemb@google.com>
> > 
> > In preparation for extending to pacing hardware offload, convert the
> > so_txtime.sh test to a drv-net test that can be run against netdevsim
> > and real hardware.
> > 
> > Two preparatory patches
> > 1. support negative tests, where tests are expected to fail
> > 2. add a tc helper 
> > 
> > See individual patches for details and detailed changelog
> 
> Hi Willem! Looks like we have some flakiness here:
> 
> https://netdev.bots.linux.dev/contest.html?executor=vmksft-net-drv-dbg&test=so-txtime-py

Argh sorry. I should have run dbg mode, but hadn't.

The previous version skips all receiver errors if KSFT_MACHINE_SLOW is
set, as of commit a7ee79b9c455 ("selftests: net: cope with slow env in
so_txtime.sh test").

This achieves the same in the new version and seems to indeed mask all
the timing (and other) errors in debug mode.

	@@ -24,8 +25,12 @@ def test_so_txtime(cfg, clockid, ipver, args_tx, args_rx, expect_success):
	     cmd_rx = f"{cmd_base} {args_rx} -r"
	     cmd_tx = f"{cmd_base} {args_tx}"
	 
	+    expect_fail = not expect_success
	+    if os.environ.get('KSFT_MACHINE_SLOW'):
	+        expect_success = False
	+
	     with bkg(cmd_rx, host=cfg.remote, fail=expect_success,
	-             expect_fail=(not expect_success), exit_wait=True):
	+             expect_fail=expect_fail, exit_wait=True):
		 cmd(cmd_tx)