FreeBSD 5.2R+C: panic: kmem_malloc(4096): kmem_map too small

Colin Percival colin.percival at
Sat Jan 17 11:03:10 PST 2004

At 17:25 17/01/2004, Peter Wood wrote:
>I have come accross a reproducable panic in bother 5.2-Release and 5.2-Current
>(as it was an hour ago). To perform this, I create two 750Mb memory disks,
>format them and mount them.

   Quote from the mdconfig(8) man page:
 >             malloc   Storage for this type of memory disk is allocated with
 >                      malloc(9).  This limits the size to the malloc bucket
 >                      limit in the kernel.  If the -o reserve option is not
 >                      set, creating and filling a large malloc-backed memory
 >                      disk is a very easy way to panic a system.

   It doesn't look like this is going to be fixed any time soon -- see the
discussion under pr kern/53350 -- so for now the answer is simply "don't do

Colin Percival

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