panic: APIC: Previous IPI is stuck

Hi,

While buildworlding (Straight buildworld, no -jX), I managed to get the 
following at the serial console. The system is a Dual Athlon 2000+ MP on 
an Asus A7M266D w/3.5GB running an SMP kernel as of:

FreeBSD 5.2-CURRENT #7: Wed Jul 14 19:36:00 EDT 2004
     root_at_bling.home:/usr/CURRENT/sys/i386/compile/BLING

panic: APIC: Previous IPI is stuck
cpuid = 0;
KDB: stack backtrace:
kdb_backtrace(60737992,0,60752233,a9f44bf4,100) at 0x605782ae
panic(60752233,60553c7a,607b5be0,1,2) at 0x6055d8a3
lapic_ipi_vectored(fc,1,a9f44c84,a9f44c84,64faf780) at 0x606e3233
ipi_selected(2,fc,a9f44c40,606f31c5,a9f44c84) at 0x606e8284
forward_statclock(a9f44c84,65282780,a9f44c6c,606e0048,a9f44c84) at 
0x606e8199
pmap_rltacziynftirx(:a 9sfp4u4nc 8f4o,r0 ,56040f0b0f0c0108
,a9f44c80,8) at 0x606f31c5
intr_execute_handlers(64f574f0,a9f44c84,a9f44cc8,606dc923,38) at 
0x606e0048
lapic_handle_intr(38) at 0x606e2dca
Xapic_isr1() at 0x606dc923
--- interrupt, eip = 0x608e9135, esp = 0xa9f44cc8, ebp = 0xa9f44cc8 ---
acpi_cpu_c1(1,1,0,607b5be0,a9f44cfc) at 0x608e9135
acpi_cpu_idle(a9f44d14,60545f87,607b5c20,2,607351dc) at 0x608e8fe6
cpu_idle(607b5c20,2,607351dc,53,a9f44d34) at 0x606e4858
idle_proc(0,a9f44d48,60735072,328,0) at 0x60545f87
fork_exit(60545f50,0,a9f44d48) at 0x60545cb2
fork_trampoline() at 0x606dc5cc
--- trap 0x1, eip = 0, esp = 0xa9f44d7c, ebp = 0 ---
KDB: enter: panic

I am a little worried by the line that starts with pmap_rltac. It appears 
to be the output of two interleaved messages, which I have yet to make 
sense of. At this point the machine is deadlocked and nothing short of a 
reset will get it to budge.

Any ideas?
Andy

> Andre Guibert de Bruet | Enterprise Software Consultant >
> Silicon Landmark, LLC. | http://siliconlandmark.com/    >