>
> On 11 October 2012 at 6:55, Paul Davis wrote:
>
>> 2. chrt: failed to set pid 0's policy: Operation not permitted
>>> Checking the ability to prioritize processes with chrt... no - not good
>>> Could not assign a 80 rtprio value. Set up limits.conf.
>>> For more information, see
>>>
>>>
http://wiki.linuxmusicians.com/doku.php?id=system_configuration#limits.c...
>>>
>>> I did make the changes outlined at the above link. I still
>>> get the above report. I'm going to guess that I need some
>>> real-time support from the kernel to make this work. Which
>>> brings me to
>>
>> this is not true.
http://jackaudio.org/realtime_vs_realtime_kernel
>
> OK. That's a pleasant answer. :-)
>
> I added this:
>
> ::::::::::::::
> /etc/security/limits.d/93-audio_limits.conf
> ::::::::::::::
> # Increase priority of audio applications
> # maximum realtime priority
> @audio - rtprio 90
> # maximum locked-in-memory address space (KB)
> @audio - memlock 2000000
>
>
> Fedora's jack-audio-connection-kit-1.9.8-9.fc17.x86_64 package added this:
>
> ::::::::::::::
> /etc/security/limits.d/95-jack.conf
> ::::::::::::::
> # Default limits for users of jack-audio-connection-kit
>
> @jackuser - rtprio 70
> @jackuser - memlock 4194304
>
> @pulse-rt - rtprio 20
> @pulse-rt - nice -20
>
>> you *must* get these permissions correct ...
>
> By permissions, are you meaning
>
> crw-rw---- 1 root audio 10, 228 Oct 10 22:47 /dev/hpet
> crw-rw---- 1 root audio 254, 0 Oct 10 22:47 /dev/rtc0
>
> [kevinc #28] groups
> kevinc root adm disk wheel cdrom man floppy games audio users jackuser
>
>>> 3. Kernel with Real-Time Preemption... not found - not good
>>
>> not necessarily relevant. required in cases where the kernel and h/w are
>> cooperating (badly) to prevent low latency operation, but many people have
>> systems where this is not required.
>
> I'm having IRQ crowding issues, and I was headed at trying to
> get rtirq going in order to help this. I believe rtirq *does*
> require an RT kernel.
>
http://wiki.linuxmusicians.com/doku.php?id=system_configuration#rtirq