Re: [PATCH iproute2 0/3] Add JSON output support to the remaining qdiscs

[Stephen Hemminger <stephen@networkplumber.org>]

On Wed, 11 Feb 2026 14:07:22 -0300
Victor Nogueira <victor@mojatatu.com> wrote:

> Since qdisc core already assumes all qdiscs are able to output JSON,
> add JSON output support to the remaning qdiscs (HFSC, QFQ, muiltiq)
> so that a JSON qdisc dump outputs valid JSON.
> 
> Victor Nogueira (3):
>   tc: Add JSON output support to HFSC
>   tc: Add JSON output support to QFQ
>   tc: Add JSON output support to multiq
> 
>  tc/q_hfsc.c   | 29 ++++++++++++++++++-----------
>  tc/q_multiq.c |  4 +++-
>  tc/q_qfq.c    |  8 ++++----
>  3 files changed, 25 insertions(+), 16 deletions(-)
> 

Good start but some minor issues found by AI patch review 

Must-fix bug in patch 1/3 (HFSC): Copy-paste error on line printing
level — it uses st->period instead of st->level, silently emitting
wrong data in both text and JSON modes.

Design concerns worth discussing:

HFSC d (delay) field is emitted as a human-readable string in JSON
("5ms") rather than a raw numeric value (microseconds), which goes
against the iproute2 JSON convention that JSON should carry raw values
for script consumption

HFSC service curve keys use flat compound names with spaces ("rt m1")
rather than nested JSON objects — functional but awkward for consumers

multiq bands emits a compound string ("3/16") rather than separate
numeric fields — once this JSON format ships it becomes API