Re: [PATCH RFC 11/20] ctlv: Prepare runtime introspection

[Jason Gunthorpe]

On Fri, Oct 30, 2026 at 10:53:11AM +0100, Jiri Pirko wrote:
> >So.. how about could we drop the sets, use a direct description of the
> >layout and do something else for the ID numbering? Maybe the numbering
> >can be solved directly by only listing the names in:
> >
> >numbering:
> >  - device-get.reply
> >  - device-get.reply.caps
> >  - device-get.caps.evidence
> >  -[..]
> >
> >?
> 
> I'm still committed to implicit numbering. For "inline records" I
> resolved it by having it encoded as a tree with 4 levels:
> 
>  63         48 47 46 45        32 31  28 27  24 23  20 19  16 15               0
> +-------------+-----+------------+------+------+------+------+------------------+
> |   family    |kind |   index    |  L1  |  L2  |  L3  |  L4  |      field       |
> +-------------+-----+------------+------+------+------+------+------------------+
>               |<------------------ record ------------------>|

Fascinating idea. Sort of like an oid

I guarentee we will run out of bits someday :) I saw recently we ran
out of bits in RDMA :\ 3 bits seems like quite a small number..

Maybe increasing op to 128 bits?

Maybe family/kind/index/field spread over the first 64 and then the
Lx's over the second?

At the very least there should be an escape hatch so that if this
becomes too small there is a way to opt into some new layout and fix
it without breaking everything.

Jason