--- fs/nfsserver/nfs_nfsdcache.c.orig	2012-02-29 21:07:53.000000000 -0500
+++ fs/nfsserver/nfs_nfsdcache.c	2012-10-03 08:23:24.000000000 -0400
@@ -164,8 +164,19 @@ NFSCACHEMUTEX;
 int nfsrc_floodlevel = NFSRVCACHE_FLOODLEVEL, nfsrc_tcpsavedreplies = 0;
 #endif	/* !APPLEKEXT */
 
+SYSCTL_DECL(_vfs_nfsd);
+
+static int	nfsrc_tcphighwater = 0;
+SYSCTL_INT(_vfs_nfsd, OID_AUTO, tcphighwater, CTLFLAG_RW,
+    &nfsrc_tcphighwater, 0,
+    "High water mark for TCP cache entries");
+static int	nfsrc_udphighwater = NFSRVCACHE_UDPHIGHWATER;
+SYSCTL_INT(_vfs_nfsd, OID_AUTO, udphighwater, CTLFLAG_RW,
+    &nfsrc_udphighwater, 0,
+    "High water mark for UDP cache entries");
+
 static int nfsrc_tcpnonidempotent = 1;
-static int nfsrc_udphighwater = NFSRVCACHE_UDPHIGHWATER, nfsrc_udpcachesize = 0;
+static int nfsrc_udpcachesize = 0;
 static TAILQ_HEAD(, nfsrvcache) nfsrvudplru;
 static struct nfsrvhashhead nfsrvhashtbl[NFSRVCACHE_HASHSIZE],
     nfsrvudphashtbl[NFSRVCACHE_HASHSIZE];
@@ -781,8 +792,15 @@ nfsrc_trimcache(u_int64_t sockref, struc
 {
 	struct nfsrvcache *rp, *nextrp;
 	int i;
+	static time_t lasttrim = 0;
 
+	if (NFSD_MONOSEC == lasttrim &&
+	    nfsrc_tcpsavedreplies < nfsrc_tcphighwater &&
+	    nfsrc_udpcachesize < (nfsrc_udphighwater +
+	    nfsrc_udphighwater / 2))
+		return;
 	NFSLOCKCACHE();
+	lasttrim = NFSD_MONOSEC;
 	TAILQ_FOREACH_SAFE(rp, &nfsrvudplru, rc_lru, nextrp) {
 		if (!(rp->rc_flag & (RC_INPROG|RC_LOCKED|RC_WANTED))
 		     && rp->rc_refcnt == 0