vm.kmem_size

[grarpamp]

How small and big can I realistically push vm.kmem_size to on this
platform with RELENG_8 GENERIC before kernel crashes?

CPU: Intel(R) Pentium(R) 4 CPU
real memory  = 2147483648 (2048 MB)
avail memory = 2085355520 (1988 MB)

If it matters, I am using defaults for ZFS and everything else.
First set is barely primed. Second set is well used.
I often see another 100M of wired mem up to 675M'ish.

# booted
vm.kmem_map_free: 630730752
vm.kmem_map_size: 19271680
vm.kmem_size_scale: 3
vm.kmem_size_max: 335544320
vm.kmem_size_min: 0
vm.kmem_size: 650000000
vm.kvm_free: 54521856
vm.kvm_size: 1073737728
vfs.zfs.mfu_size: 482816
vfs.zfs.mru_size: 2186240
vfs.zfs.anon_size: 16384
vfs.zfs.arc_meta_limit: 101562500
vfs.zfs.arc_meta_used: 3519512
vfs.zfs.arc_min: 50781250
vfs.zfs.arc_max: 406250000
kstat.zfs.misc.arcstats.p: 203125000
kstat.zfs.misc.arcstats.c: 406250000
kstat.zfs.misc.arcstats.c_min: 50781250
kstat.zfs.misc.arcstats.c_max: 406250000
kstat.zfs.misc.arcstats.size: 3532312
kstat.zfs.misc.arcstats.hdr_size: 58324
kstat.zfs.misc.arcstats.data_size: 2685440
kstat.zfs.misc.arcstats.other_size: 788548

Mem: 1660K Active, 2692K Inact, 31M Wired, 8K Cache, 7200K Buf, 1958M Free

ITEM                     SIZE     LIMIT      USED      FREE  REQUESTS  FAILURES
zfs_znode_cache:          268,        0,       43,       13,       43,        0

         Type InUse MemUse HighUse Requests  Size(s)
      solaris  6742  6505K       -    38161  16,32,64,128,256,512,1024,2048,4096


# used
vm.kmem_map_free: 145154048
vm.kmem_map_size: 481452032
vm.kmem_size_scale: 3
vm.kmem_size_max: 335544320
vm.kmem_size_min: 0
vm.kmem_size: 650000000
vm.kvm_free: 46133248
vm.kvm_size: 1073737728
vfs.zfs.mfu_size: 131460608
vfs.zfs.mru_size: 217134080
vfs.zfs.anon_size: 262144
vfs.zfs.arc_meta_limit: 101562500
vfs.zfs.arc_meta_used: 108829156
vfs.zfs.arc_min: 50781250
vfs.zfs.arc_max: 406250000
kstat.zfs.misc.arcstats.p: 228111557
kstat.zfs.misc.arcstats.c: 374401883
kstat.zfs.misc.arcstats.c_min: 50781250
kstat.zfs.misc.arcstats.c_max: 406250000
kstat.zfs.misc.arcstats.size: 364867900
kstat.zfs.misc.arcstats.hdr_size: 2751420
kstat.zfs.misc.arcstats.data_size: 348670976
kstat.zfs.misc.arcstats.other_size: 13445504

Mem: 206M Active, 82M Inact, 571M Wired, 21M Cache, 19M Buf, 1112M Free

ITEM                     SIZE     LIMIT      USED      FREE  REQUESTS  FAILURES
zfs_znode_cache:          268,        0,    10419,      123,    12786,        0

         Type InUse MemUse HighUse Requests  Size(s)
      solaris 206261 391419K       - 11430057
16,32,64,128,256,512,1024,2048,4096