Re: a joint letter on low latency and Linux

[Cort Dougan]

I think this allows (and encourages) a bad programming model.  Imagine the
glee a RT programmer experiences when they think they get all of libc for
free in a RT application.

I've had a bit of experience with the ugliness and not clearly defined
behavior that mixing RT and non-RT code gives.  I believe that decoupling
the two needs into separate pieces of code, as with RTLinux, is the way to
go.

} I'd still prefer the scheme I suggested a while back: run Linux
} processes on the RT scheduler if they have RT priority, and switch
} between RT and Linux scheduler whenever going between user-space and
} kernel-space.
} 
} This would mean you get complete access to all system calls and user
} libraries within a RT process, without having to bloat the kernel with
} a pile of pseudo-RT hacks.
} 
} It would also mean we could consider ripping out SCHED_FIFO and
} SCHED_RR from the Linux scheduler, hence simplifying it.
} 
} Somebody please find the time to implement this :-)