On Mon, 16 Feb 2026 16:30:29 +0100 Jesper Dangaard Brouer wrote:

Create new enum qdisc_drop_reason and trace_qdisc_drop tracepoint
for qdisc layer drop diagnostics with direct qdisc context visibility.

The new tracepoint includes qdisc handle, parent, kind (name), and
device information. Existing SKB_DROP_REASON_QDISC_DROP is retained
for backwards compatibility via kfree_skb_reason().

Convert qdiscs with drop reasons to use the new infrastructure.

Change CAKE's cobalt_should_drop() return type from enum skb_drop_reason
to enum qdisc_drop_reason to fix implicit enum conversion warnings.
Use QDISC_DROP_UNSPEC as the 'not dropped' sentinel instead of
SKB_NOT_DROPPED_YET. Both have the same compiled value (0), so the
comparison logic remains semantically equivalent.

net/sched/sch_dualpi2.c:594:12: warning: implicit conversion from enumeration type 'enum qdisc_drop_reason' to different enumeration type 'enum skb_drop_reason' [-Wimplicit-enum-enum-cast]
  593 |                         drop_and_retry(q, skb, sch,
      |                         ~~~~~~~~~~~~~~
  594 |                                        QDISC_DROP_CONGESTED);
      |                                        ^~~~~~~~~~~~~~~~~~~~
-- 
pw-bot: cr