Subject: Kernel hang in amap_wipeout
To: None <>
From: Robert Swindells <>
List: tech-kern
Date: 02/20/2003 23:55:08
I am getting a "fatal page fault in supervisor mode" from amap_wipeout()
whenever I exit from a lisp system that I am trying to debug.

The lisp system (CMUCL) has allocated a lot of anonymous maps, which
may not be the most sensible thing to do, but I wouldn't expect it
to bring down the whole system.

I have got a debug kernel built, and can probably provide remote access
to the system if it helps.

The stack dump is:

db> t
amap_wipeout(e43a61e8,e43c1088,e3959edc,c01df930,e43d5800) at amap_wipeout+0x1d
amap_unref(e43a61e8,afa,fb,0,e4394004) at amap_unref+0x23
uvm_unmap_detach(e438d1d8,0,bfc00000,e3959f38,0) at uvm_unmap_detach+0x57
uvmspace_free(e4394004,e4393004,e3959f8c,c01c87b6,e4393004) at uvmspace_free+0x66
uvm_proc_exit(e436869c,e4393004,1,e393b380,e393b380) at uvm_proc_exit+0x14
reaper(e393b380,0,0,0,c010030c) at reaper+0xdd

The first bit of dmesg.boot is:

NetBSD 1.6N (SHUTTLE) #0: Thu Feb 20 22:20:17 GMT 2003
total memory = 1015 MB
avail memory = 940 MB
using 6144 buffers containing 52096 KB of memory
BIOS32 rev. 0 found at 0xfb3f0
mainbus0 (root)
cpu0 at mainbus0: (uniprocessor)
cpu0: Intel Pentium III (686-class), 997.25 MHz, id 0x68a
cpu0: features 387f9ff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,SEP,MTRR>
cpu0: features 387f9ff<PGE,MCA,CMOV,PAT,PSE36,PN,MMX>
cpu0: features 387f9ff<FXSR,SSE>
cpu0: I-cache 16 KB 32b/line 4-way, D-cache 16 KB 32b/line 4-way
cpu0: L2 cache 256 KB 32b/line 8-way
cpu0: ITLB 32 4 KB entries 4-way, 2 4 MB entries fully associative
cpu0: DTLB 64 4 KB entries 4-way, 8 4 MB entries 4-way
cpu0: serial number 0000-068A-0003-AD14-9982-F6B6
cpu0: 8 page colors
pci0 at mainbus0 bus 0: configuration mode 1
pci0: i/o space, memory space enabled, rd/line, rd/mult, wr/inv ok

Any thoughts on what to look at first ?

Robert Swindells