"fast data access mmu miss" on kernels w/o "makeoptions DEBUG=-g"

[John Baldwin]

On Friday 19 August 2005 02:17 am, John Nielsen wrote:
> On Friday 19 August 2005 12:30 am, Pyun YongHyeon wrote:
> > On Thu, Aug 18, 2005 at 09:24:58AM -0400, John Nielsen wrote:
> >  > On Wednesday 17 August 2005 16:59, Marius Strobl wrote:
> >  > > On Mon, Aug 15, 2005 at 10:42:36AM -0400, John Nielsen wrote:
> >  > > > On Friday 12 August 2005 00:53, Andrew Belashov wrote:
> >  > > > > John Nielsen wrote:
> >  > > > > > Can anyone say why removing "makeoptions DEBUG=-g" from a
> >  > > > > > kernel would make it unreliable?  I'm on an Ultra 5, and it's
> >  > > > > > quite stable with either GENERIC or the kernel specified
> >  > > > > > below.  However, commenting out the "makeoptions DEBUG=-g"
> >  > > > > > line builds a kernel that boots but then panics right after
> >  > > > > > mounting /:
> >  > > > > >
> >  > > > > > Entropy harvesting: interrupts ethernet point_to_pointpanic:
> >  > > > > > trap: fast data access mmu miss
> >  > > > > > Uptime:2s
> >  > > > > > Dumping 512 MB (2 chunks)
> >  > > > >
> >  > > > > Try to clean rebuild kernel (remove build directory
> >  > > > > /usr/obj/usr/src/sys/KERNCONF or /sys/compile/KERNCONF).
> >  > > >
> >  > > > No change even after a fresh buildworld (using RELENG_6):
> >  > > >
> >  > > > cvsup /etc/supfile-src && rm -r /usr/obj/* && cd /usr/src && make
> >  > > > make && make clean && make cleandir && make cleandir && make
> >  > > > buildworld && make buildkernel && make installkernel && make
> >  > > > installworld && mergemaster
> >  > > >
> >  > > > I don't mind leaving the option in the kernel, but it does seem
> >  > > > like a strange bug.  Let me know if anyone has any other ideas.
> >  > > > Thanks,
> >  > >
> >  > > When the DEBUG make option is defined the compiler optimization
> >  > > flags (COPTFLAGS) default to '-O -pipe' whereas without DEBUG the
> >  > > default is '-O2 -pipe' ('-O2' can cause bogus stack traces so it's
> >  > > not the default for debugging kernels). So in case you also get a
> >  > > panic with a kernel having both:
> >  > > makeoptions	DEBUG=-g
> >  > > and:
> >  > > makeoptions	COPTFLAGS="-O2 -pipe"
> >  > > this probably means that there's bogus code that breaks at higher
> >  > > optimization levels or a compiler bug. A stack trace from such a
> >  > > panic might help to track this down in case it's not screwed due
> >  > > to the '-O2'.
> >  >
> >  > That's what it was.  A kernel with only
> >  > makeoptions COPTFLAGS="-O -pipe"
> >  > builds and runs just fine.
> >
> > Are you sure that GENERIC kernel panics too?
> > I couldn't verify it(I'm on a business trip) but I guess you should
> > remove smbfs related kernel options. smbfs never worked on sparc64
> > and it needs more clean up on various places.
> > If you encounter the panic again would you post stack traces?
>
> Yes, I built about 20 kernels trying to track it down, including GENERIC
> sans makeoptions DEBUG=-g (but with WITNESS, etc).
>
> I haven't actually tried to use SMBFS yet, but simply having it in the
> kernel doesn't seem to be affecting anything.
>
> I'll see if I can get a stacktrace from an existing dump.

My ultra60 won't boot a kernel that doesn't have WITNESS in it FWIW.  Try a 
stock GENERIC kernel and see if it works.  You can disable witness with the 
loader tunable 'debug.witness.watch=0'.

-- 
John Baldwin <jhb at FreeBSD.org>  <><  http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve"  =  http://www.FreeBSD.org