>Number:         7996
>Category:       port-i386
>Synopsis:       panic: pagedaemon: clean anon page without backing store?
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    port-i386-maintainer (NetBSD/i386 Portmaster)
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Jul 14 17:05:01 1999
>Last-Modified:
>Originator:     Ed Gould
>Organization:
--
Ed Gould	 Palo Alto Advanced Development	 Compaq Computer Corp.
+1 650 853 2108	 ed@pa.dec.com			 130 Lytton Avenue
		 ed.gould@compaq.com		 Palo Alto, CA 94301
>Release:        NetBSD 1.4
>Environment:
System: NetBSD toblerone.pa.dec.com 1.4 NetBSD 1.4 (TOBLERONE) #4: Tue Jul 6 18:09:16 PDT 1999 ed@toblerone.pa.dec.com:/usr/src/sys/arch/i386/compile/TOBLERONE i386


>Description:
	The kernel reproducably crashes with "panic: pagedaemon: clean anon
	page without backing store?" when doing a cvs checkout, upon
	encountering a particular very large (20+MB) file.  The
	checkout is going into a local directory; the CVS tree is NFS
	mounted.

	I have a core dump from the crash.  The machine is a Digital
	Celebris GL 6200, a 200-MHz Pentium Pro, 32MB RAM, 128MB swap.  More
	details available if necessary.

	The stack trace from the dump is

	(gdb) bt
	#0  0xf02717b6 in uvm_pageout ()
	#1  0xf027aba7 in cpu_reboot ()
	#2  0xf0189471 in panic ()
	#3  0xf0271a6d in uvmpd_scan_inactive ()
	#4  0xf0271f43 in uvmpd_scan ()
	#5  0xf0271717 in uvm_pageout ()
	#6  0xf0177cac in start_pagedaemon ()

>How-To-Repeat:
	See above.

>Fix:
	Not a clue.  The code that's calling the panic is inside a
	#ifdef DIAGNOSTIC; I have no idea how serious it would be to
	remove the test.
>Audit-Trail:
>Unformatted: