Re: [PATCH] i386 reduce spurious interrupt noise

[Chris Wedgwood]

On Fri, Sep 10, 2004 at 11:23:20PM +0200, Maciej W. Rozycki wrote:

> > -	printk (KERN_INFO "APIC error on CPU%d: %02lx(%02lx)\n",
> > +	printk (KERN_DEBUG "APIC error on CPU%d: %02lx(%02lx)\n",

> This should probably be KERN_ERR even.  This is a serious condition -- if
> you ever get such a message, then inter-APIC messages get corrupted and
> this affects system's stability.

These messages are very common on many platforms, infrequent (once
very few days to twice a day at most in my observations) and seemingly
harmless.

I agree that if you get *many* of these certainly that would indicate
there is a problem but I've not not heard a single instance of this
and if that is the case we need to deal with it differently.

> > -			printk("spurious 8259A interrupt: IRQ%d.\n", irq);
> > +			printk(KERN_DEBUG "spurious 8259A interrupt: IRQ%d.\n", irq);

> You may ever get a single message per system boot from this line.

Sometimes as boot, though often in my experience several minutes after
boot.

> It encourages to have a look at the ERR counter in /proc/interrupts
> to check for possible problems, though admittedly the suggestion
> isn't especially clear.

I think in *both* cases we want to detect a largish (more than 1 ever
n seconds or so) number of these and then complain, not before and
even then not excessively so that we printk our-selves to death.

I'm not inclined to offer such a patch right now as it feels like it's
fixing a problem nobody has reported.


  --cw
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