alex_joni, I'm here
reading the -beyond stuff
Yes, that's a good patchset
I want to tailor my system for the desktop
I heard stuff about it, but I thought it's still kinda far away from switching latencies we need
And I don't mean the usual desktop ;)
kinda guessed that ;)
I don't know about the latencyies because I'm trying it today
brokenthorn: the thing is that we use RT to output stepper pulses (for motor control), so it's kinda critical
if the pulses don't arrive when they should, the motor WILL stall
Yes... I've seen the project
Pretty interesting :D
not always stepper output, but that's the most problematic
But I want a real-time kernel, or as much as it gets
and the problem is to have it ALWAYS reliable.. not 99% of the time
well, the RTAI stuff takes a different approach
And you run Ubuntu on the machine?
it basicly installs underneath the linux
and runs when it should :)
gives control back to the kernel when it's idle
Hm... doesn't sound like me
brokenthorn: yes, Ubuntu
I want it to 'run' all the time
And what happens to the usplash?
this happens usually very fast (few usecs), so you don't notice it
Do you still have that?
brokenthorn: usplash stays black when I tried to install a custom one
the default one works ok
Did RTAI patch the kernel?
they provide patches, yes
Did you made a config based on the stock kernel's one?
So usplash is userland
all linux is userland
What does it need in the kernel to work? vesafb-tng and fbconsole ?
only specific coded parts are RT
fbcon & vesa16fb I think
but the RT part is way later, after the system booted
yup, that's the ubuntu default
Why not vesafb?
it's the latest best
dunno, probably ubuntu people decided 16 is more spread?
not my call :)
did you lose the initrd?
so you still use that
it's needed for fbcon afaik
I decided not to use it and it can't mount the root partition
I get a kernel panic at boot
What kind of machine does Ubuntu run on?
any x86 fwiw
ubuntu also runs on at least pcc and x86_64, but there's no realtime kernel built for them.
No, I was wondering about the kernel config you use
I don't know what to keep not to break any ubuntu compatibility
did you patched a vanilla kernel?
because the kernel in the repos have lots of ubuntu patches
I wonder if it's going to break something
I don't have those arch's I have i686 (pentium 4 2.4GHz)
I need to know if using a patched vanilla kernel with the -beyond patchset or any patchset will break ubuntu!!!
brokenthorn: I used the ubuntu sources
and tiny tweaked the rtai patches
but you'll be best asking in #ubuntu-kernel
I must have missed the beginning of this conversation. What is "the -beyond patchset"?
[13:31:05] <brokenthorn> http://members.optusnet.com.au/ckolivas/kernel/
jepler: some patch to improve latency on a default kernel
not much documentation though
jepler, Look at "Other interesting links"
this also has some relevance: http://freequaos.host.sk/schedtool/
but I think it's still pretty far away from what we need
wouldn't you want the rt kernel even for servo cards? or are the computers fast enough now?