Re: [PATCH v11 net-next 1/5] Documentation: netlink: specs: tc: Add DualPI2 specification

[Paolo Abeni <pabeni@redhat.com>]

On 4/15/25 2:43 PM, chia-yu.chang@nokia-bell-labs.com wrote:
> From: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com>
> 
> Introduce the specification of tc qdisc DualPI2 stats and attributes,
> which is the reference implementation of IETF RFC9332 DualQ Coupled AQM
> (https://datatracker.ietf.org/doc/html/rfc9332) providing two different
> queues: low latency queue (L-queue) and classic queue (C-queue).
> 
> Signed-off-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com>
> ---
>  Documentation/netlink/specs/tc.yaml | 144 ++++++++++++++++++++++++++++
>  1 file changed, 144 insertions(+)
> 
> diff --git a/Documentation/netlink/specs/tc.yaml b/Documentation/netlink/specs/tc.yaml
> index aacccea5dfe4..0fb971935285 100644
> --- a/Documentation/netlink/specs/tc.yaml
> +++ b/Documentation/netlink/specs/tc.yaml
> @@ -816,6 +816,58 @@ definitions:
>        -
>          name: drop-overmemory
>          type: u32
> +  -
> +    name: tc-dualpi2-xstats
> +    type: struct
> +    members:
> +      -
> +        name: prob
> +        type: u32
> +        doc: Current probability
> +      -
> +        name: delay_c
> +        type: u32
> +        doc: Current C-queue delay in microseconds
> +      -
> +        name: delay_l
> +        type: u32
> +        doc: Current L-queue delay in microseconds
> +      -
> +        name: pkts_in_c
> +        type: u32
> +        doc: Number of packets enqueued in the C-queue
> +      -
> +        name: pkts_in_l
> +        type: u32
> +        doc: Number of packets enqueued in the L-queue
> +      -
> +        name: maxq
> +        type: u32
> +        doc: Maximum number of packets seen by the DualPI2
> +      -
> +        name: ecn_mark
> +        type: u32
> +        doc: All packets marked with ecn
> +      -
> +        name: step_mark
> +        type: u32
> +        doc: Only packets marked with ecn due to L-queue step AQM
> +      -
> +        name: credit
> +        type: s32
> +        doc: Current credit value for WRR
> +      -
> +        name: memory_used
> +        type: u32
> +        doc: Memory used in bytes by the DualPI2
> +      -
> +        name: max_memory_used
> +        type: u32

Here and in other numeric fields you should probably want to use 'uint'
type, that will allow either 32 or 64 bits integers depending on the
actual value and will make possible overflows harder.

> +        doc: Maximum memory used in bytes by the DualPI2
> +      -
> +        name: memory_limit
> +        type: u32
> +        doc: Memory limit in bytes
>    -
>      name: tc-fq-pie-xstats
>      type: struct
> @@ -2299,6 +2351,92 @@ attribute-sets:
>        -
>          name: quantum
>          type: u32
> +  -
> +    name: tc-dualpi2-attrs
> +    attributes:
> +      -
> +        name: limit
> +        type: u32
> +        doc: Limit of total number of packets in queue
> +      -
> +        name: memlimit
> +        type: u32
> +        doc: Memory limit of total number of packets in queue
> +      -
> +        name: target
> +        type: u32
> +        doc: Classic target delay in microseconds
> +      -
> +        name: tupdate
> +        type: u32
> +        doc: Drop probability update interval time in microseconds
> +      -
> +        name: alpha
> +        type: u32
> +        doc: Integral gain factor in Hz for PI controller
> +      -
> +        name: beta
> +        type: u32
> +        doc: Proportional gain factor in Hz for PI controller
> +      -
> +        name: step_thresh
> +        type: u32
> +        doc: L4S step marking threshold in microseconds or in packet (see step_packets)
> +      -
> +        name: step_packets
> +        type: flags
> +        doc: L4S Step marking threshold unit
> +        entries:
> +        - microseconds
> +        - packets
> +      -
> +        name: min_qlen_step
> +        type: u32
> +        doc: Pacekts enqueued to the L-queue can apply the step threshold when the queue length of L-queue is larger than this value. (0 is recommended)

Typo above, should likely be 'Packets'

/P