Re: SCHED_FIFO and SCHED_RR broken by cfs

[Dario Faggioli]

On Sat, 2008-08-16 at 23:29 +0200, Stefani Seibold wrote:
> After disabling kernel support for "Group CPU scheduler" and applying
> 'echo -1 > /proc/sys/kernel/sched_rt_runtime_us' the behaviour is as
> expected.
> 
> chrt -f 99 ./a.out
> 
>  average:13 usec
>  min. jitter:0 usec
>  max. jitter:29 usec
> 
> chrt -o 0 ./a.out 
>  average:153 usec
>  min. jitter:0 usec
>  max. jitter:37035 usec
> 
> So the problem is located first in the new sched_rt_runtime_us default
> value and second in the "Group CPU scheduler".
Well, if you have group scheduling configured I think you should do both
# echo -1 > /proc/sys/kernel/sched_rt_runtime_us
# echo -1 > /dev/cgroup/cpu.rt_runtime_us

if /dev/cgroup is the mount point of the cgroup file system.

In situations like the one you are describing, this worked for me...
Hope that it also helps you! :-)

Regards,
Dario

-- 
<<This happens because I choose it to happen!>>
(Raistlin Majere, DragonLance Chronicles -Dragons of Spring Drawning-)
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