Bozitaai wrote:
Platform => Linux 2.4.32 with RTAI
Development in User Space
I am developing the UDP Packet Scheduler, which sends the UDP packets at
particular time, the target transport rate is 20Mbits/s and the time
different between each UDP packet is about 500 microseconds. The
transmission time must be very precisely, otherwise the buffer of
receiver will be under-flow or over-flow.
In my program, nanosleep function is used to control the time, and I
observed the kernel sometimes schedules to do other lower priority
tasks. It makes my program sometimes occurs LONG DELAY, about 20 ~ 60
milliseconds, and my program can't use 100% resource of whole Linux system.
I was trying different methods, for example, low-latency patch,
preemption patch and hrt patch, but the problem still doesn't been solved.
Any idea can share with me? Thank you very much
Use SCHED_FIFO/SCHED_RR coupled with memlock and pass to 2.6.xx with
full preemption enabled. I think Linux will then grant 1 ms. Better say
likely up to 2 ms in my (limited) experience.
If it is not enough try RTAI and rtnet.
Paolo.
-------------------------------------------------------
This SF.Net email is sponsored by xPML, a groundbreaking scripting language
that extends applications into web and mobile media. Attend the live webcast
and join the prime developer group breaking into this new coding territory!
http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642
_______________________________________________
RTnet-users mailing list
RTnet-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/rtnet-users
