Re: panic on acpi_cpu_c1()

> Fatal trap 30: reserved (unknown) fault while in kernel mode
> cpuid = 3; apic id = 03
> instruction pointer     = 0x20:0xffffffff804bce56
> stack pointer           = 0x20:0xffffff8000039b60
> frame pointer           = 0x20:0xffffff8000039b70
> code segment            = base 0x0, limit 0xfffff, type 0x1b
>                        = DPL 0, pres 1, long 1, def32 0, gran 1
> processor eflags        = interrupt enabled, IOPL = 0
> current process         = 11 (idle: cpu3)
> [thread pid 11 tid 100003 ]
> Stopped at      acpi_cpu_c1+0x6:        leave
> db> bt
> Tracing pid 11 tid 100003 td 0xffffff8001863720
> acpi_cpu_c1() at acpi_cpu_c1+0x6
> acpi_cpu_idle() at acpi_cpu_idle+0x20c
> sched_idletd() at sched_idletd+0x123
> fork_exit() at fork_exit+0x117
> fork_trampoline() at fork_trampoline+0xe

As for me, r194984 runs normally, but when I tried to boot with
r194985 at second try it paniced with backtrace very similar to shown
in first message, and at first try even earlier: in sched_ideltd and
again on instruction that uses %ebp when ebp = 0.
First time I stepped on this panic after updating to r195130:

Trying to mount root from ufs:/dev/ufs/root


Fatal trap 30; reserved (unknown) fault while in kernel mode
cpuid = 1; apic id = 01
instruction ponter      = 0x20:0xc09252c5
stack pointer           = 0x28:0xc4ecec94
frame pointer           = 0x28:0xc4ecec94
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, def32 1, gran 1
processor eflags        = interrupt enabled, IOPL = 0
current process         = 11 (idle: cpu1)
[thread pid 11 tid 100003]
Stopped at      0xc09252c5 = acpi_cpu_c1+0x5:    popl     %ebp
db> bt
Tracing pid 11 tid 100003 td 0xc5176af0
acpi_cpu_c1(1,c4ececa8,1,0,c4ececc0,...) at 0xc09252c5 = acpi_cpu_c1+0x5
acpi_cpu_idle(c4ececd4,c093c0ab,0,c4ececf4,c066fdec,...) at 0xc04acf37
= acpi_cpu_idle+0x107
cpu_idle_acpi(0,c4ececf4,c066fdec,0,0,...) at 0xc093d5bb = cpu_idle_acpi+0x1b
cpu_idle(0,0,c5176af0,c4ececf4,202,...) at 0xc093c0ab = cpu_idle+0x1b
sched_idletd(0,c4ececd38,a4108400,2c0a0e,7022d00,...) at 0xc066fdec =
sched_idletd+0x1c
fork_exit(c066fdd0,0,c4eced38) at 0xc0623aa1 = fork_exit+0x91
fork_trampoline() at 0xc0930c80 = fork_tramoline+0x8
--- trap 0, eip = 0, esp = 0xc4ececd70, ebp = 0 ---


P.S.: i386, dual-core, drm and radeon compiled as modules
When I'm trying to boot w/o ACPI support all seems work fine, but
system hangs just before starting kdm