Hi, I'm a student from Sweden that study computer science att Halmstad H�gskola http://www.hh.se/english. I would be thankful if someone would take the time and give your view of this.
Right now I'm writing a paper about Linux and realtime. I'm trying to give a brief overview of what is available today and what the future have in mind. I also try to explain the technical differences between the systems, advantages and disadvantages. I have read a paper from QNX http://www.qnx.com/literature/whitepapers/reallinux.html. They said of course that their solution is the best:-) Even if they don't mention RTLinux directly it's obvious that they mean RTLinux when they compare different solutions. In short they say that the main disadvantages of RTLinux is: 1. Duplicated coding effort. As there are two kernels running there's a need for drivers in the realtime kernel if the service want be deterministic. This means also that more memory is needed for the extra code. 2. Realtime tasks aren't protected by a MMU like ordinary Linux-tasks. 3. Limited portability of realtime tasks. etc. It was interesting to see your view of this and maybe if you have som shortcomings in QNX as this is two different approaches on the same problem. And now my own questions about RTLinux... 1. What are the main reason that the standard Linux-kernel isn't preemptable from the beginning? Performance? 2. Realtimetasks all share their userspace and aren't memprotected, right? Isn't it possible to implement this in some way. Honestly I don't think RTLinux will success in critical processes if this situation remain. 3. "Hardware context switching provided by x86 is not used." This sentence is from page 14 on http://www.rtlinux.org/documents/RTLinux.ppt. Is there any reason for this? Regards Roland -- [rtl] --- To unsubscribe: echo "unsubscribe rtl" | mail [EMAIL PROTECTED] OR echo "unsubscribe rtl <Your_email>" | mail [EMAIL PROTECTED] -- For more information on Real-Time Linux see: http://www.rtlinux.org/
