I've seen the panic triggered by assertion at uvm_bio.c:257 on both
netwinder and shark (both diskless):

         KASSERT(umap->refcount != 0);

I reliably get it running a test suite that executes a bunch of
commands with output to file.  I get it when the output file is either
on nfs or mfs.

I have just reproduced the same panic with:

$ yes | sed 1000000q | while read; do				\
    ( echo -n 1 >>XXX; echo -n 2 >>XXX; echo -n 3 >>XXX );	\
done


Anyone seen this?

SY, Uwe
-- 
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