Re: ZFS kmem_map too small.

Pawel Jakub Dawidek <pjd_at_FreeBSD.org> writes:
> I'm not sure if it's not too late to ask re_at_ about increasing the
> default kmem size at least on amd64. ~300MB we have there is silly
> small.

Speaking of which, I tried setting vm.kmem_size to 2G on a C2D system
with 4 GB RAM, but it simply panics:

OK set vm.kmem_size=2G
OK boot -s
GDB: no debug ports present
KDB: debugger backends: ddb
KDB: current backend: ddb
Copyright (c) 1992-2007 The FreeBSD Project.
Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993, 1994
        The Regents of the University of California. All rights reserved.
FreeBSD is a registered trademark of The FreeBSD Foundation.
FreeBSD 7.0-CURRENT #8: Tue Sep 25 13:31:41 CEST 2007
    des_at_ds4.des.no:/usr/obj/usr/src/sys/ds4
kmem_suballoc: bad status return of 3.
panic: kmem_suballoc
cpuid = 0
KDB: enter: panic
[thread pid 0 tid 0 ]
Stopped at      kdb_enter+0x31: popq    %rbp
db> where
Tracing pid 0 tid 0 td 0xffffffff805af4a0
kdb_enter() at kdb_enter+0x31
panic() at panic+0x166
kmem_suballoc() at kmem_suballoc+0xc3
kmeminit() at kmeminit+0x16e
mi_startup() at mi_startup+0x59
btext() at btext+0x2c
db> reset

with vm.kmem_size unset and vm.kmem_size_max=2G, it boots fine:

Timecounter "i8254" frequency 1193182 Hz quality 0
CPU: Intel(R) Core(TM)2 CPU          6600  _at_ 2.40GHz (2400.01-MHz K8-class CPU)
  Origin = "GenuineIntel"  Id = 0x6f6  Stepping = 6
  Features=0xbfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE>
  Features2=0xe3bd<SSE3,RSVD2,MON,DS_CPL,VMX,EST,TM2,SSSE3,CX16,xTPR,PDCM>
  AMD Features=0x20100800<SYSCALL,NX,LM>
  AMD Features2=0x1<LAHF>
  Cores per package: 2
usable memory = 4286398464 (4087 MB)
avail memory  = 4130979840 (3939 MB)
ACPI APIC Table: <GBT    GBTUACPI>
FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs
 cpu0 (BSP): APIC ID:  0
 cpu1 (AP): APIC ID:  1
ioapic0: Changing APIC ID to 2
ioapic0 <Version 2.0> irqs 0-23 on motherboard
[...]

DES
-- 
Dag-Erling Smørgrav - des_at_des.no