[PlanetCCRMA] Re: [PlanetCCRMANews] added: new edge
kernels for fc2/3
Rui Nuno Capela
rncbc@rncbc.org
Wed Mar 23 00:45:03 2005
> On Tue, 2005-03-22 at 19:49, Shayne O'Connor wrote:
>> Fernando Lopez-Lezcano wrote:
>>
>> >No, not "0' certainly :-)
>> >You can run this:
>> > /etc/rc.d/init.d/rtirq status
>> >that will print the priority of the interrupt request handlers, I think
>> >think the second down from the top should be your soundcard (check to
>> >see which interrupt it is using by doing "cat /proc/interrupts/"). I
>> >think the best option would be to use a slightly lower priority than
>> >that (so that first to run is the interrupt handler and then jack). 60
>> >should be close.
>> >
>> >
>> here's the output for rtirq:
>>
>> PID CLS RTPRIO NI PRI %CPU STAT COMMAND
>> 277 FF 80 -5 120 0.0 SW< IRQ 8
>> 879 FF 60 -5 100 0.1 SW< IRQ 22
>> 952 FF 60 -5 100 0.0 SW< IRQ 20
>> 927 FF 59 -5 99 0.0 SW< IRQ 21
>> 375 FF 50 -5 90 0.0 SW< IRQ 1
>> 20 FF 49 -5 89 0.0 SW< IRQ 9
>> 298 FF 49 -5 89 0.0 SW< IRQ 12
>> 334 FF 46 -5 86 0.0 SW< IRQ 14
>> 336 FF 45 -5 85 0.0 SW< IRQ 15
>> 1882 FF 40 -5 80 0.0 SW< IRQ 7
>> 2054 FF 39 -5 79 0.0 SW< IRQ 6
>> 3447 FF 38 -5 78 0.2 SW< IRQ 19
>> 3698 FF 37 -5 77 0.1 SW< IRQ 17
>>
>> and cat /proc/interrupts:
>>
>> CPU0
>> 0: 1743956 IO-APIC-edge timer 0/43956
>> 1: 410 IO-APIC-edge i8042 0/410
>> 7: 2 IO-APIC-edge parport0 0/0
>> 8: 1 IO-APIC-edge rtc 0/1
>> 9: 0 IO-APIC-level acpi 0/0
>> 12: 152827 IO-APIC-edge i8042 160/52826
>> 14: 18240 IO-APIC-edge ide0 44/18240
>> 15: 477 IO-APIC-edge ide1 0/477
>> 17: 121688 IO-APIC-level EMU10K1 77/21688
>> 19: 106598 IO-APIC-level nvidia 7/6598
>> 20: 0 IO-APIC-level ohci_hcd 0/0
>> 21: 0 IO-APIC-level ohci_hcd 0/0
>> 22: 175682 IO-APIC-level ehci_hcd, eth0 178/75682
>> NMI: 0
>> LOC: 1738855
>> ERR: 0
>> MIS: 0
>>
>> as you can see, my soundcard is *last* rtirq list ... isn't irq 17 the
>> worst possible irq for the soundcard to be on? geez, could mean another
>> trip inside the computer ...
>
> Strange. This could be a bug in the way rtirq orders the interrupts. The
> priority order is determined by rtirq, not by the internal ordering
> within the BIOS and won't be changed by swapping cards around (unless
> that un-triggers the problem in rtirq).
>
> You could try to change the priority of irq17 and see if that affects
> realtime behavior. You need to use the chrt command, as in (for example
> above, this will probably change if you reboot):
> chrt -f -p 61 3698
> (the last number is the pid of the irq handler for irq17)
>
> Rui: what do you think? I have not looked at the script yet...
>
The ALSA module (snd-emu10k1?) *must* be loaded prior to rtirq start.
Otherwise IRQ 17 won't be detected as the soundcard handler.
What's the output of
cat /proc/asound/cards
at the time rtirq started? Whenever ALSA is loaded, it should show at
least one line with the string "irq 17" on it, unless something got really
broken.
Bye now.
--
rncbc aka Rui Nuno Capela
rncbc@rncbc.org