Re: Embedded Linux Vs. Real time Linux



Michael Schnell wrote:

So what you are saying is that the Linux kernel WILL disable global
interrupts from time to time.

AFAIK, this is correct (maybe depending on the CPU architecture). You
need to inspect the Kernel sources to be sure.

But this is the approach of the RT Preempt patch: To reduce the need of
disabling the interrupt and replace this code by simple spin locks or
mutexes. This means the word "preemption". Ensure every piece of code can
be preempted if something with a higher priority is ready to work. So also
the interrupt service routines are kernel threads now, and with a priority.

On a DualCore-Pentium with RT Preempt we need more than 10000 hackbench jobs
and a two ping floods to see latency violations on this box....

JB
.