> > Hello. > > I installed RTLinux on my AMDk6 430 MHZ with 128 Mb RAM and up to now I've just > been probing with the example programs. > I have tried the hello.c with various thread periods and observed that when I > try periods of less than 10us my system crashes. Is this a normal limit? Is it > a > hardware limit or is it an RTLinux limit? > If I can't schedule periodic threads with less than 10us period that will mean > that if the thread is used to aquire samples from a DAQ board I will have a > 100KHz sampling rate limit, which I find a bit low for my needs.Is it possible > to achieve higher sampling rates with RTLinux? > Well your system does not crash - Linux just never got scheduled again as you were using 100% of the CPU for your rt-thread... so rtlinux performed just perfect ;)
10us is atleast close to the limit on the platform you mention - do a tight loop and check how long the execution time of gethrtime is - I would be supprised if it is far below 2-3us (which is the timing precision the system can't get below) - so the execution time of even a short thread + calling the sheduler is quite posible to be 10us. If you need 10us then you have two options, the beter one is use an SMP system and a dedicated CPU for your RT-thread, the not so good solution is to find a very fast system (K7 1.2GHz, with no buss-problems, perfect hardware components, flawless-RAM...) and run a 100KHz task on a UP system... hofrat -- [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/
