> poorly- or even maliciously-coded applications can never be ruled out,
What I meant here was, an app with lots of round trips in its protocol design or that shovels loads of data over the bus is going to be a perf problem. As a practical matter if you have user-visible situation xyz that appears slow, fixing dorky app behavior can be the fastest way to fix xyz.
> there's no reason they can't both happen
That's why I keep lobbying for the userspace changes to happen - a couple of them looked like they'd only take a few days of work. Hey, for all I know, someone did them already over the last few months. Anyway it's just bugging me (as you've no doubt gathered) that the kernel stuff is a kind of multi-year undertaking due to the difficult political issues, while the performance could be greatly improved without blocking on kernel devs...
So I'm just trying to give the potential userspace tasks some PR. Maybe someone reading these comments will want to work on them, we can dream...
(I know I'm telling those close to dbus things they already know. But it may not be apparent to those who aren't close to it that there's stuff they could do today.)