On Wed, 3 Dec 1997, Frank van der Linden wrote:

> On Tue, Dec 02, 1997 at 11:37:32AM -0800, Matthew P. Jacob wrote:
> > 
> > -current sources as of Nov 30:
> > 
> >  panic: pmap_page_protect !PG_V: ctx 0, va 0xf0173000, pte 0x0
> > Stopped at      _Debugger+0x4:  jmpl            [%o7 + 0x8], %g0
> > Frame pointer is at 0xf18e6c00
> 
> This may be the same swap/MFS problem that can be seen on the i386
> resulting in "pmap_changebit" crashed due to a zero PTE, when called
> from the pageout daemon. See PR port-i386/4281, it was also noticed
> by some other people recently.
> 
> I have been able to reproduce it once, using MFS too. Of course, when
> I installed a new kernel with more debug info, it did not crash no
> matter what I did..
> 

It's not exactly like the above, but I've been seeing the following
panics ever since the last round of sparc changes. It seems to me that
having my SS2 use a serial console aggravates the problem. When the 
system first comes up, if I hit return on the serial console, then
telnet in from another system, I almost always get a panic.

BTW, I'm not using MFS, but it is compiled into the kernel.

I just noticed that I didn't have any swap configured (forgot to add
it to the fstab). Is swap required?

login: data fault: pc=0xf0106c2c addr=0x69740034 ser=8080<WRITE,INVAL>
panic: kernel fault
Stopped at      _Debugger+0x4:  jmpl            [%o7 + 0x8], %g0
db> trace
_mem_access_fault(0x9, 0x8080, 0x69740034, 0xf0106c2c, 0x110007c4, 0xf1a2ed48) a
t _mem_access_fault+0x298
normal_mem_fault(0xf016a540, 0x69740030, 0x2000, 0xf016a540, 0x0, 0xf07c3f80) a
t normal_mem_fault+0x28
_vm_map_lookup(0xf028d008, 0x2000, 0xf07c3f80, 0x2000, 0xf1a2ee98, 0xf1a2ee94) a
t _vm_map_lookup+0x5c
_vm_fault(0x0, 0xffdf, 0x1, 0xf017d400, 0x0, 0x1) at _vm_fault+0x338
_mem_access_fault(0xf07bb500, 0x80, 0x100f2580, 0x10013b6c, 0x11400080, 0xf1a2e
fb0) at _mem_access_fault+0x1a8
normal_mem_fault(0x2, 0x1, 0x8, 0xffffffff, 0x10080000, 0x100f2580) at normal_m
em_fault+0x28
db>


login: async mem arr: ser=0 sva=0x10021594 aer=21<TIMEOUT> ava=0xf01acff8
parity error register = 0
panic: memory error
Stopped at      _Debugger+0x4:  jmpl            [%o7 + 0x8], %g0
db> trace
_memerr(0xf014df08, 0x0, 0x10021594, 0x321, 0xf01acff8, 0x14) at _memerr+0xdc
nmi_common(0xf01ab000, 0xf01ac000, 0xfe8, 0x6e14b96e, 0x0, 0x0) at nmi_common
_pmap_copy_page4_4c(0xa000122c, 0x6e2f696e, 0xf017d658, 0xf016a540, 0x0, 0xf077
2180) at _pmap_copy_page4_4c+0xf0
_vm_page_copy(0xf0244308, 0xf028cfe0, 0xf017d5e0, 0x11000, 0xf1a14e98, 0xf1a14e
94) at _vm_page_copy+0x1c
_vm_fault(0xf075a600, 0xffdf, 0x1, 0xf017d400, 0x0, 0x3) at _vm_fault+0x6fc
_mem_access_fault(0xf07bd100, 0x8080, 0x10021594, 0x100102cc, 0x11000083, 0xf1a
14fb0) at _mem_access_fault+0x1a8
normal_mem_fault(0xeffffca4, 0x10021594, 0x10020bf8, 0xffffffff, 0x0, 0xf1a14fb
0) at normal_mem_fault+0x28
db>


db> trace
_mem_access_fault(0x9, 0x8080, 0x69740034, 0xf0106c2c, 0x110007c1, 0xf1a2e878) a
t _mem_access_fault+0x298
normal_mem_fault(0xf016a540, 0x69740030, 0x0, 0xf016a540, 0x0, 0xf07c2a80) at n
ormal_mem_fault+0x28
_vm_map_lookup(0xf028d008, 0x0, 0xf07c2a80, 0x0, 0xf1a2e9c8, 0xf1a2e9c4) at _vm
_map_lookup+0x298
_vm_fault(0x0, 0xffdf, 0x1, 0xf017d400, 0x0, 0x3) at _vm_fault+0x338
_mem_access_fault(0x9, 0x8020, 0xf02f7000, 0xf0007c88, 0x114000c5, 0xf1a2eae0) a
t _mem_access_fault+0x144
normal_mem_fault(0xf0ebe000, 0xf02f7000, 0xff8, 0x0, 0x2800005, 0xba102000) at n
ormal_mem_fault+0x28
_uiomove(0xf0ebe000, 0x1000, 0xf1a2eca0, 0x13, 0x2000, 0xffffffff) at _uiomove+
0xdc
_ffs_read(0x0, 0x1000, 0xf07ba700, 0xf07bea80, 0xffffffff, 0x100) at _ffs_read+
0x20c
_vnode_pager_io(0xf07b8b60, 0x27000, 0x1, 0x1000, 0x0, 0xf1a2efb0) at _vnode_pa
ger_io+0x18c
_vnode_pager_getpage(0xf07a2640, 0xf1a2ee48, 0x1, 0x1, 0xf010a564, 0xf1a2efb0) a
t _vnode_pager_getpage+0x14
_vm_pager_get_pages(0xf07a2640, 0xf1a2ee48, 0x1, 0x1, 0x0, 0xf07ba100) at _vm_p
ager_get_pages+0x58
_vm_pager_get(0xf07a2640, 0xf028cfe0, 0x1, 0x27000, 0xf1a2ee98, 0xf1a2ee94) at _
vm_pager_get+0x14
_vm_fault(0xf07ba100, 0xffdf, 0x0, 0xf017d400, 0x0, 0x1) at _vm_fault+0x468
_mem_access_fault(0xf07bf700, 0x80, 0x294c4, 0x294c4, 0x11400086, 0xf1a2efb0) a
t _mem_access_fault+0x1a8
normal_mem_fault(0x39000, 0x36000, 0x0, 0x1, 0x1, 0x0) at normal_mem_fault+0x28

db>