zfs panic

[ben wilber]

Hi,

Since at least r208174, I've been getting the following panic every few days on
my fairly heavily loaded amd64 machine:

panic: _sx_xlock_hard: recursed on non-recursive sx buf_hash_table.ht_locks[i].ht_lock @ /usr/src/sys/modules/zfs/../../cddl/contrib/opensolaris/uts/c
ommon/fs/zfs/arc.c:1626

The machine has 36 disks behind mfi(4), plus some SATA L2ARC.  This
panic is sometimes preempted by "kmem_map too small", so I apologize in
advance if this is caused by memory shortage.