Hi, about scheduling performance comparisons between RTAI and RTL, please note: RTAI retains the old RTL registers save/restore at interrupts so it should be somewhat more effective as it saves less. However this is not finally true because it always take cares of the cr0 register to ease the use of the FPU in interrrupt handlers without any problem. Moreover, as we are not good in asm, we have left the saving-restore of the bp register as C does. (It will be changed in the -fomit-frame-pointer way to enhance efficiency). RTAI should be more effective in the periodic case when it schedules out of a task because it does not go through the timed list as it is not needed. Most important when many tasks are there. It is much more effective in the oneshot case and on Pentiums because it times completly on the cpu. Here it outperforms RTL for sure, at least till RTL will not use apics (but what for in UniProcessors?). I'm curious to see how performances will compare with the use of apics in the oneshot case. I expect no advantage for apic timers in the periodic case. Right now it is not cleaned for UP and must be compiled with SMP, both it and the kernel, so some small overheads are there because of not needed spinlocks. The SMP porting of the scheduler is completed but even if the version available now works on complex test cases some bugs have already been discovered and a more robust release will be available within a week (co LLP), with full function calls docs. No use is made of local apics as we do not know nothing about them yet. Note that, following the RTAI scheduler implementation, the RTL scheduler could become SMP in a couple of days without any major redesign. All the scheduler performances issues are not so important because the most relevant factors should be the services available within the scheduler, if you need them, and the jitter. The latter should be not much different as the basics of RTAI is the same of the old RTL. It is the implementation architecture that is different. Ciao, Paolo. --- [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/~rtlinux/
