net: sch_fq: update flow delivery time on earlier EDT packet

When inserting an EDT packet with time before flow->time_next_packet,
update the flow and possibly queue next delivery time.

Reinsert the flow into the q->delayed rb-tree to position correctly
and to have fq_check_throttled set wake-up at the right next time.

Factor RB tree insertion out fq_flow_set_throttled to avoid open
coding twice.

EDT packets do not take precedence over queue rate limit. Skip this
new step if a queue limit is set. EDT packets do take precedence over
per-socket rate limits, as can be seen from fq_dequeue reading
sk_pacing_rate if !skb->tstamp.

With this change the so_txtime selftest sends packets in the expected
order.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260526134109.2624493-1-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/tools/testing/selftests/drivers/net/so_txtime.py b/tools/testing/selftests/drivers/net/so_txtime.py
index e7de8fe22c1e..5d4388bfc6dd 100755
--- a/tools/testing/selftests/drivers/net/so_txtime.py
+++ b/tools/testing/selftests/drivers/net/so_txtime.py
@@ -53,7 +53,7 @@ def _test_variants_mono():
             ["zero_delay", "a,0", "a,0"],
             ["one_pkt", "a,10", "a,10"],
             ["in_order", "a,10,b,20", "a,10,b,20"],
-            ["reverse_order", "a,20,b,10", "b,20,a,20"],
+            ["reverse_order", "a,20,b,10", "b,10,a,20"],
         ]:
             name = f"v{ipver}_{testcase[0]}"
             yield KsftNamedVariant(name, ipver, testcase[1], testcase[2])