Date: Fri, 19 Aug 2005 02:17:15 -0400 From: John Nielsen <john@jnielsen.net> To: pyunyh@gmail.com Cc: freebsd-sparc64@freebsd.org Subject: Re: "fast data access mmu miss" on kernels w/o "makeoptions DEBUG=-g" Message-ID: <200508190217.15943.john@jnielsen.net> In-Reply-To: <20050819043026.GC10519@rndsoft.co.kr> References: <200508110931.13802.john@jnielsen.net> <200508180924.59562.john@jnielsen.net> <20050819043026.GC10519@rndsoft.co.kr>
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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.
JN
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