kern/73094: [unionfs] system runs out of vnodes

[Irina Liakh]

The following reply was made to PR kern/73094; it has been noted by GNATS.

From: Irina Liakh <spell at itl.ua>
To: David Schultz <das at FreeBSD.ORG>
Cc: FreeBSD-gnats-submit at FreeBSD.ORG
Subject: Re: kern/73094: [unionfs] system runs out of vnodes
Date: Tue, 26 Oct 2004 11:21:28 +0300

 On Mon, Oct 25, 2004 at 04:47:34PM -0400, David Schultz wrote:
 > What makes you think this has something to do with the resident
 > page count, as opposed to v_usecount?
 
 I've inserted to getnewvnode()
 
 	printf("vtryrecycle() error: %d\n", error);
 
 after
 
 	error = vtryrecycle(vp);
 
 recompiled kernel, rebooted and got permanent (while find <unionfs_mount_point>)
 
 	vtryrecycle() error: 16 
 
 (EBUSY) on system console
 
 Then I've inserted similar printf()-code to vtryrecycle()
 and located that vtryrecycle fails here:
 
                 if (object->resident_page_count ||
                     object->ref_count) {
                         VM_OBJECT_UNLOCK(object);
                         error = EBUSY;
 
 Then inserted here
 
 	printf("resident_page_count=%d ref_count=%d\n",
 		object->resident_page_count, object->ref_count)
 
 and got permanent
 
 	resident_page_count=1 ref_count=0
 
 at system console.