5 Mar
2011
5 Mar
'11
4:26 p.m.
On Sat, Mar 5, 2011 at 10:25 PM, Robin Gareus <robin(a)gareus.org> wrote:
> quick glance: I got the impression that it only addresses scheduling
> policy (task partitioning) and not realtime task preemption. Also
> software needs to be written dedicated for Litmus RT.
Judging from the installation instructions, it seems preemption is there:
> cd litmus-rt
> patch -p1 < ../litmus-rt-2011.1.patch
> # create a working kernel configuration
> # - select HZ=1000
> # - enable in-kernel preemptions
> # - disable NO_HZ
> # - don't use power management options like frequency scaling
> # - disable support for group scheduling
> # - disable "Write protect kernel read-only data structures" (in kernel
debug)
> I got the feeling from reading that the
main thing missing is some kind of
sane interface for assigning RT priviliges to non-root users. Then again,
that maybe covered to some degree in the provided liblitmus which in turn
provides:
rt_launch, which can be used to start arbitrary programs as real-time tasks.
If I get adventurous I may try compiling this thing to see what I can see.
Most of it is over my head and I'll take your word for it that this is far
from userland friendly or ready, but it looks like a fun learning exercise.
-m