amd64/106186: panic in swap_pager_swap_init (amd64/smp/6.2-pre)

Alex Vasylenko lxv at
Fri Dec 1 18:50:11 PST 2006

>Number:         106186
>Category:       amd64
>Synopsis:       panic in swap_pager_swap_init (amd64/smp/6.2-pre)
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    freebsd-amd64
>State:          open
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Sat Dec 02 02:50:06 GMT 2006
>Originator:     Alex Vasylenko
>Release:        FreeBSD 6.2-PRERELEASE amd64
System: FreeBSD blackbox.intranet 6.2-PRERELEASE FreeBSD 6.2-PRERELEASE #1: Fri Dec 1 20:36:12 EST 2006 root@:/usr/obj/usr/src/sys/GENERIC-AMD64-C amd64

I tried to upgrade an amd64x2 box from "FreeBSD 6.1-STABLE #36: Mon Sep
4 11:22:15 EDT 2006" to "FreeBSD 6.2-PRERELEASE #1: Mon Nov 13 10:01:57
EST 2006" and found that a newly built kernel panics on boot as follows:
SMP: AP CPU #1 Launched!
panic: failed to create swap_zone.
cpuid = Trying to mou0
KDB: enter: nt root from ufpanic
[thread pid 40 tid 100040 ]
Stopped at      kdb_enter+0x2f
db> where
Tracing pid 40 tid 100040 td 0xffffff003b9e24c0
kdb_enter() at kdb_enter+0x2f
panic() at panic+0x291
swap_pager_swap_init() at swap_pager_swap_init+0x20c
vm_pageout() at vm_pageout+0x17c
fork_exit() at fork_exit+0x86
fork_trampoline() at fork_trampoline+0xe
--- trap 0, rip = 0, rsp = 0xffffffffa753bd00, rbp = 0 ---

old dmesg:
new dmesg (-v):
kernel config:

There are several known workarounds:
- GENERIC (UP) kernel works fine;
- my kernel (a stripped down SMP) with "options SMP" removed works;
- my kernel with SMP enabled and either -v or -d (followed by cont)

... and the best one discovered by another person who also experiences this
- have FireWire-related drivers removed from kernel configuration file

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