[LAU] chrt doesn't seem to be working

[David Causse]

Ken Restivo a écrit :
> On Mon, Nov 19, 2007 at 09:41:19PM +0100, David Causse wrote:
>   
>> Ken Restivo a écrit :
>>     
>>> I'm having a bit of difficulty getting chrt to, um, chrt.
>>>
>>> I've written a little MIDI-processing daemon and I want it to run with high priority. It is very small and tight and I don't expect it to take up much CPU, but I definitely want it running first.
>>>
>>> So I do this:
>>> 	sudo /usr/bin/chrt -f -p 81 `pidof mydaemon`
>>>
>>> And then I do this:
>>> 	ps -Leo pid,class,rtprio,ni,pri,pcpu,stat,comm --sort -rtprio
>>>
>>> And... my daemon does *not* show up in the process list at all.
>>>   
>>>       
>> Try this :
>> ps Haxo pid,class,rtprio,ni,pri,pcpu,stat,comm --sort=-rtprio
>> --sort seems to skip some processes with the -edf syntax style, I don't 
>> know why...
>>     
>
> Excellent! That ps cocktail shows it, and it is apparently working. Thanks!
>
>   
>> But your process won't be on top because you have set the SCHED_FIFO 
>> wich is not rtprio.
>> You should use :
>> chrt -p 81 `pidof mydaemon`
>> SCHED_RT is the default.
>>
>>     
>
>
> Um... JACKD runs in FIFO mode, or isn't that what the "FF" means in the ps?
>
>   PID CLS RTPRIO  NI PRI %CPU STAT COMMAND
> 25176 FF      80   - 120  0.0 SLsl jackd
>
>
>   
You're right, I misunderstood sched_fifo, it is the realtime scheduling 
policy, sched_rt is my invention ;)

David.