On Wed, Jan 10, 2024 at 9:05 AM Masahiko Sawada <sawada.mshk@gmail.com> wrote:
>
> I've done in 0010 patch in v51 patch set. Whereas RT_NODE_4 and
> RT_NODE_16 structs declaration needs RT_FANOUT_4_HI and
> RT_FANOUT_16_HI respectively, RT_FANOUT_16_LO and RT_FANOUT_48 need
> RT_NODE_16 and RT_NODE_48 structs declaration. So fanout declarations
> are now spread before and after RT_NODE_XXX struct declaration. It's a
> bit less readable, but I'm not sure of a better way.
They were before and after the *_BASE types, so it's not really worse,
I think. I did notice that RT_SLOT_IDX_LIMIT has been considered
special for a very long time, before we even had size classes, so it's
the same thing but even more far away. I have an idea to introduce
*_MAX macros, allowing to turn RT_SLOT_IDX_LIMIT into
RT_FANOUT_48_MAX, so that everything is in the same spot, and to make
this area more consistent. I also noticed that I'd been assuming that
RT_FANOUT_16_HI fits easily into a DSA size class, but that's only
true on 64-bit, and in any case we don't want to assume it. I've
attached an addendum .txt to demo this idea.
