Re: try KMGUARD

[Paul Goyette <paul%whooppee.com@localhost>]

I re-ran testing with an 'options DEBUG'  kernel, and kmem_guard_depth 
was set to 20k pages.  ATF failed again in the same manner, but none of 
the DEBUG tools triggered, not even KMEM_GUARD.  Not sure how else to 
debug this...

FWIW, here's the traceback from the current failure:

lib/libc/gen/posix_spawn/t_fileactions (193/499): 5 test cases
    t_spawn_empty_fileactions: [0.573848s] Passed.
    t_spawn_fileactions: [0.154962s] Passed.
    t_spawn_open_nonexistent: fatal page fault in supervisor mode
trap type 6 code 0 rip ffffffff8061128e cs 8 rflags 246 cr2  0 cpl 8 rsp 
fffffe8002c75ae0
panic: trap
cpu0: Begin traceback...
printf_nolog() at netbsd:printf_nolog
startlwp() at netbsd:startlwp
alltraps() at netbsd:alltraps+0xa2
mi_switch() at netbsd:mi_switch+0x2c5
kpreempt() at netbsd:kpreempt+0xe2
Xpreemptrecurse() at netbsd:Xpreemptrecurse+0x15
spawn_return() at netbsd:spawn_return+0x1f8
cpu0: End traceback...


On Wed, 7 Mar 2012, Mindaugas Rasiukevicius wrote:

> Paul Goyette <paul%whooppee.com@localhost> wrote:
> > > Debugging such memory corruptions is difficult.  Can you try running
> > > with KMGUARD enabled?  See the bottom of kmem(9) man page how to enable
> > > it.
> > >
> > > One might need to try different depth levels as the system can run out
> > > of memory very quickly.  This requires 64-bit machine, e.g. amd64 (i386
> > > would run out of KVA) with lots of RAM.
> >
> > I will see what I can do here.  The qemu test environment runs with
> > fairly limited memory (only 128M) so I suspect that will need to be
> > (drastically?) increased?  (My host has 32GB of real RAM but not sure
> > how much qemu can support.)
>
> Are you able to try to reproduce on a real hardware?  Resource usage by
> KMGUARD is very severe.  It might not even boot with 128 MB.
>
> --
> Mindaugas
>
> !DSPAM:4f57de8d1984501718870!

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