# KERNEL PANIC supervisor write data page not present



## WeaponX (Feb 20, 2012)

Hi, 

Every once and then I am getting the follow when booting FreeBSD 9, any idea what this is?


```
atkbd0: [GIANT-LOCKED]
coretemp0: <CPU On-Die Thermal Sensors> on cpu0
est0: <Enhanced SpeedStep Frequency Control> on cpu0
p4tcc0: <CPU Frequency Thermal Control> on cpu0
coretemp1: <CPU On-Die Thermal Sensors> on cpu1
est1: <Enhanced SpeedStep Frequency Control> on cpu1
p4tcc1: <CPU Frequency Thermal Control> on cpu1
Timecounters tick every 1.000 msec


Fatal trap 12: page fault while in kernel mode
cpuid = 0; apic id = 00
fault virtual address   = 0xd8
fault code              = supervisor write data, page not present
instruction pointer     = 0x20:0xffffffff8062a033
stack pointer           = 0x28:0xffffffff80e1acd0
frame pointer           = 0x28:0xffffffff80e1ad00
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags        = interrupt enabled, resume, IOPL = 0
current process         = 0 (swapper)
trap number             = 12
panic: page fault
cpuid = 0
Uptime: 1s
Automatic reboot in 15 seconds - press a key on the console to abort
--> Press a key on the console to reboot,
--> or switch off the system now.
```

I do have 
	
	



```
kern.timecounter.hardware=HPET
```
 is this related? I can provide additional info.


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## Dies_Irae (Feb 20, 2012)

It's usually a memory problem.

Check your RAM with Memtest86+.
It could even be a faulty hard disk, because the process that caused the panic is "swapper":

```
current process         = 0 (swapper)
```


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## WeaponX (Feb 21, 2012)

Could it be because I don't have a swap partition enabled? I have 4GB of ram with a live file-system build.

Just to let you know I did not have this problem in 8.2...


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