panic: kmem_map too small

[Robert Watson]

On Wed, 25 Oct 2006, Stefan Bethke wrote:

> We're consistely getting this panic even under smallish loads.  I've 
> experimented with various values for VM_KMEM_SIZE_MAX (384, 512, 768 and 
> 1024 MB), but the boxes are still panicking after even short periods (a few 
> hours) just doing a buildworld, a few ports compiles, or even when logging 
> out of the console(?).
>
> Would logging vm.zone every few minutes help detecting a kernel memory leak?
>
> I'm at a complete loss as to the actual cause of these.  The ACPI errors 
> precede the panic below by only a few seconds, so I'd guess they're a 
> symptom, not a cause.  We've tried with ACPI disabled in the BIOS, but we 
> also got these panics, so we re-enabled it.
>
> The hardware is a Tyan GT20 (2865) with a single-core Opteron, two gigs of 
> RAM and two or three SATA disks.
>
> Any ideas?

Try the commands "show uma" and "show malloc" in DDB to print the memory 
allocations made by the uma(9) and malloc(9) kernel memory allocators.  This 
output may be sufficient to suggest to us where a kernel memory leak, if any, 
might be taking place.  Also, a stack trace ("trace") never hurts; if 
something is sitting there allocating a lot of memory at high speed, it could 
well be that the last call to the memory allocator is the one leaking.

Robert N M Watson
Computer Laboratory
University of Cambridge

>
>
> Thanks,
> Stefan
>
>
> login:         -0255: *** Error: UtCallocate: Could not allocate size 30
>       -0255: *** Error: UtCallocate: Could not allocate size 30
>       -0255: *** Error: UtCallocate: Could not allocate size 30
>   ACPI-1304: *** Error: Method execution failed [\SWFS] (Node 0xc63ee220), 
> AE_NO_MEMORY
>   ACPI-1304: *** Error: Method execution failed [\RBYT] (Node 0xc63ee1a0), 
> AE_NO_MEMORY
>   ACPI-1304: *** Error: Method execution failed [\RTMP] (Node 0xc63ee380), 
> AE_NO_MEMORY
>   ACPI-1304: *** Error: Method execution failed [\_TZ_.THRM._TMP] (Node 
> 0xc63ede00), AE_NO_MEMORY
> panic: kmem_malloc(4096): kmem_map too small: 699756544 total allocated
> Uptime: 1h54m54s
> KDB: enter: Break sequence on console
> [thread pid 46775 tid 100060 ]
> Stopped at      kdb_enter+0x30: leave
> db>
>
>
>