[RFC][v1][Design] AP Architecture for Roaming with Wi-Fi 8 Seamless Mobility Domain (SMD)

[Johannes Berg]

On Sun, 2025-10-12 at 15:51 +0200, Johannes Berg wrote:
> > 	DL/UL traffic transition latency to the target AP MLD depends on the IAP
> > 	messages and the ST Execution Response arriving on time. Therefore, these
> > 	actions should not have to wait for pending management frames to be handled.
> 
> A good part of this argument - "pending management frames" - really goes
> back to hostapd's architecture and single-threadedness, but really I
> don't think "hostapd's current architecture implies more latency"
> implies "we must put this into the kernel."

Continuing that thought: I think that hostapd's architecture currently
leaves a lot to be desired, in particular around how MLD works, and
obviously, at least to some extent, being single-threaded is an
architectural advantage in hostapd.

However, user space also affords far more flexibility than kernel space,
for example some things could be written in rust (with its "fearless
concurrency", which I can attest to), split out to a separate thread or
process, etc.

Anyway ... I guess in a way I'm using the opportunity here to lament the
lack of architectural work in hostapd which isn't necessarily related to
this, but I suspect that had hostapd historically had more architectural
flexibility we might not even be having this discussion?

johannes