port-i386/41934: assertion "(opte & (PG_V | PG_W)) != PG_W" failed

[Manuel.Bouyer%lip6.fr@localhost]

>Number:         41934
>Category:       port-i386
>Synopsis:       assertion "(opte & (PG_V | PG_W)) != PG_W" failed
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    port-i386-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Aug 24 19:35:00 +0000 2009
>Originator:     Manuel Bouyer
>Release:        NetBSD 5.0_STABLE
>Organization:
>Environment:
System: NetBSD disco 5.0_STABLE NetBSD 5.0_STABLE (DISCO) #5: Sun Aug 16 
00:00:37 MEST 2009 
bouyer@disco:/home/bouyer/src-5/src/sys/arch/i386/compile/obj/DISCO i386
Architecture: i386
Machine: i386
>Description:
        This (UP) NFS server paniced with:
panic: kernel diagnostic assertion "(opte & (PG_V | PG_W)) != PG_W" failed: 
file "/home/bouyer/src-5/src/sys/arch/x86/x86/pmap.c", line 637
        I didn't try to get stack trace from ddb, but I do have a core dump.
        I have seen the same panic on another NFS server on another site,
        ddb didn't get much info:
panic: kernel diagnostic assertion "(opte & (PG_V | PG_W)) != PG_W" failed: 
file "/home/bouyer/src-5/src/sys/arch/x86/x86/pmap.c", line 637
Begin traceback...
uvm_fault(0xcef0f008, 0x72753000, 1) -> 0xe
fatal page fault in supervisor mode
trap type 6 code 0 eip c03f0311 cs 8 eflags 10246 cr2 72753f70 ilevel 0
panic: trap
Faulted in mid-traceback; aborting...
dumping to dev 18,1 offset 8
dump i/o error


>How-To-Repeat:
        Run NFS with lots of clients ?
>Fix:
        unknown