About Periodic Tasks

Jungwoo Yang yjwoo14 at gmail.com
Mon Apr 19 16:30:07 CEST 2010


Hello, I'm a student who are studying periodic task on L4, so I'm trying to use your cpu_reserved example. However, what I tried to use res_rt_sched or periodic. I've gotten some errors.

title Fiasco Periodic Test
kernel /bootstrap -serial -modaddr=0x06000000
module /fiasco -serial_esc -comport 1
module /sigma0
module /roottask task modname "cpu_reserved" allow_cli task modname "res_rt_sched" allow_cli
module /events
module /names --events
module /log
module /dm_phys 
module /cpu_reserved
module /res_rt_sched

This is my configuration of grub. but I have gotten some error like that.

res_rt_s|  Error: l4_rt_next_period(): Unknown (unregistered) error
res_rt_s| [A.3] cpu_reserve/examples/res_rt_sched/main.c:77:worker():
res_rt_s|  Error: l4_rt_next_period(): Unknown (unregistered) error
res_rt_s| [A.3] cpu_reserve/examples/res_rt_sched/main.c:77:worker():

When I tried to figure out the error. The problem is from "l4_rt_next_period()".  It returns 0x20 error "L4_IPC_RETIMEOUT".
I've found the error from "l4cpu_reserve_wait_periodic()" in cpu_reserved server.
The function returns 0 if the IPC returns "L4_IPC_RETIMEOUT", so I thought that "L4_IPC_RETIMEOUT" is not real error at that time.
But when I execute the compoent "res_rt_sched", it look like that it is not a periodic task.

I've spent about 3 weeks because of this.. please help me!

Thank you.



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