svn commit: r201338 - stable/8/sys/kern

[Konstantin Belousov]

Author: kib
Date: Thu Dec 31 11:49:13 2009
New Revision: 201338
URL: http://svn.freebsd.org/changeset/base/201338

Log:
  MFC r201134:
  Add a knob to allow reclaim of the directory vnodes that are source of
  the namecache records.

Modified:
  stable/8/sys/kern/vfs_subr.c
Directory Properties:
  stable/8/sys/   (props changed)
  stable/8/sys/amd64/include/xen/   (props changed)
  stable/8/sys/cddl/contrib/opensolaris/   (props changed)
  stable/8/sys/contrib/dev/acpica/   (props changed)
  stable/8/sys/contrib/pf/   (props changed)
  stable/8/sys/dev/xen/xenpci/   (props changed)

Modified: stable/8/sys/kern/vfs_subr.c
==============================================================================
--- stable/8/sys/kern/vfs_subr.c	Thu Dec 31 10:53:04 2009	(r201337)
+++ stable/8/sys/kern/vfs_subr.c	Thu Dec 31 11:49:13 2009	(r201338)
@@ -152,6 +152,10 @@ SYSCTL_LONG(_vfs, OID_AUTO, wantfreevnod
 static u_long freevnodes;
 SYSCTL_LONG(_vfs, OID_AUTO, freevnodes, CTLFLAG_RD, &freevnodes, 0, "");
 
+static int vlru_allow_cache_src;
+SYSCTL_INT(_vfs, OID_AUTO, vlru_allow_cache_src, CTLFLAG_RW,
+    &vlru_allow_cache_src, 0, "Allow vlru to reclaim source vnode");
+
 /*
  * Various variables used for debugging the new implementation of
  * reassignbuf().
@@ -643,7 +647,9 @@ vlrureclaim(struct mount *mp)
 		 * If it's been deconstructed already, it's still
 		 * referenced, or it exceeds the trigger, skip it.
 		 */
-		if (vp->v_usecount || !LIST_EMPTY(&(vp)->v_cache_src) ||
+		if (vp->v_usecount ||
+		    (!vlru_allow_cache_src &&
+			!LIST_EMPTY(&(vp)->v_cache_src)) ||
 		    (vp->v_iflag & VI_DOOMED) != 0 || (vp->v_object != NULL &&
 		    vp->v_object->resident_page_count > trigger)) {
 			VI_UNLOCK(vp);
@@ -668,7 +674,9 @@ vlrureclaim(struct mount *mp)
 		 * interlock, the other thread will be unable to drop the
 		 * vnode lock before our VOP_LOCK() call fails.
 		 */
-		if (vp->v_usecount || !LIST_EMPTY(&(vp)->v_cache_src) ||
+		if (vp->v_usecount ||
+		    (!vlru_allow_cache_src &&
+			!LIST_EMPTY(&(vp)->v_cache_src)) ||
 		    (vp->v_object != NULL &&
 		    vp->v_object->resident_page_count > trigger)) {
 			VOP_UNLOCK(vp, LK_INTERLOCK);