Re: FreeBSD 8.0-BETA2/amd64 crashes on SMP under load

On Tue, Jul 28, 2009 at 02:22:50PM +0000, O. Hartmann wrote:
> Anton Shterenlikht wrote:
> > On Mon, Jul 27, 2009 at 10:04:28PM +0100, Anton Shterenlikht wrote:
> >> On Mon, Jul 27, 2009 at 09:55:12PM +0200, O. Hartmann wrote:
> >>> Kamigishi Rei wrote:
> >>>> O. Hartmann wrote:
> >>>>> I have the problem of crashing FreeBSD 8.0-BETA2/amd64 under load on
> >>>>> all of our SMP boxes. Is there an issue known at the moment? If not, I
> >>>>> will prepare the kernel for whitnessing and provide more informations,
> >>>>> if you wish.
> >>>> A quick question: what is in the crash message, i.e. the backtrace?
> >>>> And what kind of crash is it - a panic() or a fatal trap?
> >>> On the 8-core server box, I sometimes see :
> >>>
> >>> Fatal trap 12: page fault while in kernel mode
> >>> fault code              = supervisor read, page not present
> >> Not sure if it's related, but on ia64 SMP (2 cpus) with 8.0-current and
> >> later with 8.0-beta1 (I havent' built beta2 yet) I'm getting crashes
> >> under load every so often. E.g buildworld -j8 is likely to crash the
> >> box. No messages, just a sudden freeze, no backtrace or panic, and then reboot.
> >>
> >> If load is less heavy, e.g. fewer processes and some idle time, the
> >> problem doesn't seem to appear.
> >>
> >> I'm happy to do any further testing, if suggested.
> > 
> > my ia64 8.0-beta1 SMP box died again on
> > make -j8 buildworld
> > with no panic or log entries.
> > 
> > Is it possible that some kernel variable needs to
> > be increased? E.g. kern.maxproc, kern.maxfiles, etc.
> > Or perhaps I'm talking complete rubbish..
> > 
> 
> I suggest you try again with a UP kernel - a suggestion from a 
> kernel-nnob, sorry. My SMP boxes work now with UP-kernel, but they are 
> really slowish although they have modern Intel C2D/Penryn cores.

I need SMP for OpenMP codes. It's a shame if SMP is buggy, but
I guess all is down to small user base..

-- 
Anton Shterenlikht
Room 2.6, Queen's Building
Mech Eng Dept
Bristol University
University Walk, Bristol BS8 1TR, UK
Tel: +44 (0)117 928 8233 
Fax: +44 (0)117 929 4423