On Tue, 27 Nov 2001, Roland Bengtsson wrote: > http://www.qnx.com/literature/whitepapers/reallinux.html. They said of > course that their solution is the best:-) That is normal statement. Whay would they say that somebody has a better solution than QNX.
> main disadvantages of RTLinux is: > > 1. Duplicated coding effort. As there are two kernels running there's a > need for drivers That is partly correct, > in the realtime kernel if the service want be deterministic. This > means also that more memory is needed for the extra code. Is cheap these days. > 2. Realtime tasks aren't protected by a MMU like ordinary Linux-tasks. Protected from each other? Yes. > 3. Limited portability of realtime tasks. Portability to what? Real time tasks are very hardware and runtime system dependent. > shortcomings in QNX as this is two different approaches on the same How will that help your evaluation? > 1. What are the main reason that the standard Linux-kernel isn't > preemptable from the beginning? It is a general purpose OS. > 2. Realtimetasks all share their userspace and aren't memprotected, right? Real time tasks share the kernel address space (think threads) and Linux kernel is monolithic -- a large address space.. > 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. Your insight into the future is noted. > > 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? No comments on this one. Maybe a better person will reply to this others. -ishwar -- [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/
