On Tuesday 28 September 2004 09:57 am, Mark Knecht wrote: > Mark Knecht wrote: > > brad stafford wrote: > >> I just tonight switched from the Planet CCRMA RH9 to FC1. The install > >> was purely from the CDROMs dated 4/25/2004. > >> > >> I've seen all the latest posts about interrupts and did the required > >> reading on the internet. I really managed to get RH9 cleaned up but in > >> FC1 I'm seeing something a little different. I have a Delta 1010 and I'm > >> running an AMD Barton 2.6 with 5 PCI slots. The question is what the > >> heck are IRQ 16 and 22? I moved the sound and ethernet cards around to > >> get them to 16 and 22 as they used to be eth0 on 21 and ICE1712 on 22. I > >> have ACPI turned off as a service but don't have a "disable" option in > >> the BIOS. I did turn off USB support in the BIOS. > >> > >> Is 16 like the equivalent of IRQ 3 since it's following 15? > >> > >> [brad@mars brad]$ cat /proc/interrupts > >> CPU0 > >> 0: 81690 IO-APIC-edge timer > >> 1: 75 IO-APIC-edge keyboard > >> 2: 0 XT-PIC cascade > >> 8: 1 IO-APIC-edge rtc > >> 9: 0 IO-APIC-level acpi > >> 12: 836 IO-APIC-edge PS/2 Mouse > >> 14: 10789 IO-APIC-edge ide0 > >> 15: 735 IO-APIC-edge ide1 > >> 16: 0 IO-APIC-level ICE1712 > >> 22: 21 IO-APIC-level eth0 > >> NMI: 0 > >> LOC: 81633 > >> ERR: 0 > >> MIS: 0 > >> > >> I'm getting 5.8 msec latency in JACK with 128 frames/period at 44100 and > >> 2 periods/buffer. A huge improvement over the 46.1 msec using RH9 with > >> capabilities. > >> > >> Thanks, Brad. > > > > Brad, > > First I see no reason for you to change anything. If there's no > > problem to fix, then why make a problem? > > > > Interrupts, in your case, are based on the APIC model. You machine > > has an APIC (Advanced Programmable Interrupt Controller) as well as one > > or more IO-APIC chips, so it supports more than the old style 15 > > interrupts. This is not a problem. It should be an advantage, if > > everything is set up correctly. > > > > My input would be to go with the flow. If one of these days you find > > that you are getting worse performance, be it xruns or something else, > > then come back and let's look at the setup of the machine. Until then, > > be happy. It looks like the results are quite good, right?!? > > > > Cheers, > > Mark > > One last little sickening detail I forgot to add before. Sorry for doing > it now. > > In the older 'compatibility model' we knew the 'prioity of the interrupt > from the interrupt number: 0,1,8,9,10,11,12,13,14,15,3,4,5,6,7. It was > hardwired. > > In the newer 'APIC' model all we know is the interrupt number, not the > priority. There is a secondary routing table that maps the interrupt > priority using a vector. The table is visible in dmesg on my machines. > It probably is on yours also. The meaning of the table is obscure and > has been covered here before. The 'unfortunate' aspect of the table is > that there are no generally avaialble tools to allow a system > administrator to modify the vectors and hence change the priorities of a > given hardware device. Not sure that matters to most people. I would be > happier having that capability and hope it will appear one day. > > Sorry for chiming in again. > > - Mark Aieeee! And we almost got away clean too! :) R~ -- The Road of Life is paved with Squirrels that couldn't make a decision!
