kernel panic with greater that 8 GB of memory

James R. Van Artsalen james at
Mon Nov 29 13:41:44 PST 2004

I'm not convinced that the bounce-buffer scheme works on amd64 at all.  
I don't think twe, ata or bge work (individually or in combination) with 
more than 4GB of RAM.

Are you using a bge NIC or USB, or any other driver that needs bounce 
buffer, 1394?  Which SCSI driver?

Is this 5.3 release?  5.2.1 worked for me.  The bounce-buffer code in 
amd64 has changed since then but I haven't been able to figure it out.

I wonder how much memory is in Tinderbox?

Steve Kargl wrote:

>kmem_suballoc: bad status return of 3
>panic: kmem_suballoc
>cpuid = 0
>KDB: stack backtrace:
>kdb_backtrace() at kdb_backtrace+0x37
>panic() at painc+0x1d1
>kmem_suballoc() at kmem_suballoc+0x93
>kmeminit() at kmeminit+0x16d
>mi_startuup() at mi_startup+0xb6
>btext90 at btext+0x2c
>KDB: enter: panic
>[thread pid 0 tid 0]
>This is a Tyan K8S Pro motherboard with 16 GB of PC2700
>Cosair ECC memory.  The BIOS was flashed to the latest
>available from Tyan.  The scheduler is 4BSD.  There are
>no ATA devices in the system and no ATA subsystem in
>the kernel.  This a SCSI only box.   World and kernel
>were rebuilt today with CFLAGS=-O -pipe and
>COPTFLAGS=-O -pipe.
>If I set hw.physmem="#G" n /boot/loader.conf where # is
>less than or equal to 8 the box boots up (see dmesg below).
>If # > 8, then we have the above panic.
>Any ideas where to look for the a fix?

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