Subject: Re: [PATCH net-next v2] selftests/net: SO_TXTIME with ETF and FQ

From: Vinicius Costa Gomes <[email-masked]>
Date: Fri, 24 May 2019 10:10:08 -0700

Hi,

Willem de Bruijn <[email-masked]> writes:

> From: Willem de Bruijn <[email-masked]>
>
> The SO_TXTIME API enables packet tranmission with delayed delivery.
> This is currently supported by the ETF and FQ packet schedulers.
>
> Evaluate the interface with both schedulers. Install the scheduler
> and send a variety of packets streams: without delay, with one
> delayed packet, with multiple ordered delays and with reordering.
> Verify that packets are released by the scheduler in expected order.
>
> The ETF qdisc requires a timestamp in the future on every packet. It
> needs a delay on the qdisc else the packet is dropped on dequeue for
> having a delivery time in the past. The test value is experimentally
> derived. ETF requires clock_id CLOCK_TAI. It checks this base and
> drops for non-conformance.
>
> The FQ qdisc expects clock_id CLOCK_MONOTONIC, the base used by TCP
> as of commit fb420d5d91c1 ("tcp/fq: move back to CLOCK_MONOTONIC").
> Within a flow there is an expecation of ordered delivery, as shown by
> delivery times of test 4. The FQ qdisc does not require all packets to
> have timestamps and does not drop for non-conformance.
>
> The large (msec) delays are chosen to avoid flakiness.
>
> 	Output:
>
> 	SO_TXTIME ipv6 clock monotonic
> 	payload:a delay:28 expected:0 (us)
>
> 	SO_TXTIME ipv4 clock monotonic
> 	payload:a delay:38 expected:0 (us)
>
> 	SO_TXTIME ipv6 clock monotonic
> 	payload:a delay:40 expected:0 (us)
>
> 	SO_TXTIME ipv4 clock monotonic
> 	payload:a delay:33 expected:0 (us)
>
> 	SO_TXTIME ipv6 clock monotonic
> 	payload:a delay:10120 expected:10000 (us)
>
> 	SO_TXTIME ipv4 clock monotonic
> 	payload:a delay:10102 expected:10000 (us)
>
> 	[.. etc ..]
>
> 	OK. All tests passed
>
> Changes v1->v2: update commit message output
>
> Signed-off-by: Willem de Bruijn <[email-masked]>
> Acked-by: Eric Dumazet <[email-masked]>

Acked-by: Vinicius Costa Gomes <[email-masked]>

Cheers,
--
Vinicius