Re: cpu error 4 (was: Re: O2 framebuffer problems with install kernel)

[Michael Lorenz <macallan%NetBSD.org@localhost>]

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Hello,

On Jul 29, 2008, at 12:15, Jorge Acereda Maciá wrote:

> On Jul 29, 2008, at 5:42 PM, Michael Lorenz wrote:
>
> > On Jul 29, 2008, at 11:23, Jorge Acereda Maciá wrote:
> >
> > > With the first patch (the one using BUS_DMA_COHERENT), I get  
> > > constant reboots, usually under heavy IO load (probably an  
> > > unrelated problem).
> >
> > Lots of network traffic on the onboard interface?
>
> Yes, I'll try to isolate if it's due to network IO or disk IO.

My bet is on mec - even if it works right it's not very fast and  
doesn't do stuff like checksums in hw. If you've got a PCI ethernet  
board sitting around - I can personally vouch for 3com 3c905 based  
cards to work just fine, others used DEC 2114x clones.
In theory anything supported by NetBSD should work but since the O2  
is a little more ticklish than - say, macppc and sparc - regarding  
DMA and cache synchronization ( macppc for instance is always DMA  
coherent ) I'd expect occasional trouble.

> > Any change with the 2nd patch?
>
> Well, I wanted to keep that machine self-hosting and so far I've  
> been unable to checkout the kernel sources :-)

Eh, you won't be impressed by build times.

> In any case, I still have the cross-building setup on my Mac, so  
> I'll try to build a kernel with the second patch.

That should only rebuild a single file anyway, and pretty much any  
halfway modern mac would do the job much faster than the O2, even  
with an R10k.

> > > I've also noticed messages like this printed occasionally:
> > >
> > > crime: cpu error 4 at address 4c38444
> >
> > 'illegal address' reported by crime's cpu error interrupt.  
> > Probably a speculative read - otherwise you'd get a segfault or a  
> > panic. We should probably ignore them since they're bound to  
> > happen on R10k and newer CPUs.
>
> That makes sense. I was wondering why everything kept running  
> happily after those messages.

Yeah, it's not really an error.

have fun
Michael

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