3 ms·
Interesting, though I guess there is a non-trivial performance cost to userspace drivers, seems hard to believe you could reasonably drive a GPU from userland.
by jiggy2011 13y ago
Interesting, though I guess there is a non-trivial performance cost to userspace drivers, seems hard to believe you could reasonably drive a GPU from userland. I remember John Carmack saying something about how driver overhead was the one of the biggest bottlenecks when developing modern games.
Driver quality is of course something which will always significantly rock the boat when it comes to stability but that is going to be the same with any operating system. To an extent driver quality should be a factor when choosing hardware. If you don't build your kernel with Hello Kitty support you never have to worry about that code.
I guess that is one of the reasons that Apple has a better reputation for software reliability in that for the most part they get to choose the hardware that will be used with the OS.
- justincormack 13y agoI think Apple USB drivers are userspace. USB was slow until 3.0.
- jiggy2011 13y agoI guess that would make sense, since USB peripherals are likely less performance sensitive in terms of latency and are also the place where you are going to get the widest variety of devices.
- randallu 13y agoMost GPU drivers on Linux are largely userspace based. The kernel bit has a verifier for the command buffer generated by userland to ensure it's not making the GPU read out of memory that that process shouldn't. On embedded there's less verification going on, but the drivers are still almost all in userland.