Re: [patch] 2.4.1, 2.4.2-pre3: APIC lockups

From: Frank de Lange (frank@unternet.org)
Date: Tue Feb 13 2001 - 18:20:55 EST


On Tue, Feb 13, 2001 at 09:13:10PM +0100, Maciej W. Rozycki wrote:
> There is also an additional debugging/statistics counter provided in
> /proc/cpuinfo that counts interrupts which got delivered with its trigger
> mode mismatched. Check it out to find if you get any misdelivered
> interrupts at all.

I guess you mean the MIS: counter in /proc/interrupts? This is what it says on
my box after running some 330000 interrupts (at a rate of app. 900/second)
through the network/usb IRQ:

 cat /proc/interrupts
           CPU0 CPU1
  0: 31693 32749 IO-APIC-edge timer
  1: 1208 1174 IO-APIC-edge keyboard
  2: 0 0 XT-PIC cascade
  3: 113 26 IO-APIC-edge serial
  4: 4689 4567 IO-APIC-edge serial
 14: 4440 4545 IO-APIC-edge ide0
 15: 1911 2132 IO-APIC-edge ide1
 16: 85021 84227 IO-APIC-level es1371, mga@PCI:1:0:0
 17: 26 26 IO-APIC-level sym53c8xx
 18: 0 0 IO-APIC-level btaudio, bttv
 19: 165467 166254 IO-APIC-level eth0, eth1, usb-uhci
NMI: 64376 64376
LOC: 64364 64362
ERR: 0
MIS: 647

So, that's about 650 misdelivered interrupts for 330000 deliveries (the other
interrupts never gave me any trouble, so I guess the misdelivered ones are all
from IRQ 19), or about .2%

When I load the network and stream some audio over it, the sound becomes a bit
choppy. The MIS: counter only increases when the network (read: IRQ1() is
loaded, a single audio stream (app. 220 int/sec) causes no MISses to occur.

In general, I'd say the stability WITH the patch is good, and timeouts are
withing tolerable levels. If I need something better, I'll probably get myself
a better set of network cards...

So, quick conclusion, this seems a reasonable fix...

Cheers//Frank

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This archive was generated by hypermail 2b29 : Thu Feb 15 2001 - 21:00:23 EST