revert my change to m_cluncount which tries to prevent the system

running out of mbufs for rx rings.

if the system low watermark is lower than a rx rings low watermark,
we'll never send a packet up the stack, we'll always recycle it.

found by thib@ on a bge
sadface

5 files changed, 34 insertions, 55 deletions

diff --git a/sys/dev/pci/if_em.c b/sys/dev/pci/if_em.c
index 9d7ef0b9f13..c15a6be13b7 100644
--- a/sys/dev/pci/if_em.c
+++ b/sys/dev/pci/if_em.c
@@ -31,7 +31,7 @@ POSSIBILITY OF SUCH DAMAGE.
 
 ***************************************************************************/
 
-/* $OpenBSD: if_em.c,v 1.218 2009/08/12 14:39:05 dlg Exp $ */
+/* $OpenBSD: if_em.c,v 1.219 2009/08/12 20:02:42 dlg Exp $ */
 /* $FreeBSD: if_em.c,v 1.46 2004/09/29 18:28:28 mlaier Exp $ */
 
 #include <dev/pci/if_em.h>
@@ -2649,12 +2649,10 @@ em_rxeof(struct em_softc *sc, int count)
 			    sc->last_rx_desc_filled);
 		}
 
+		m_cluncount(m, 1);
 		sc->rx_ndescs--;
-		if (m_cluncount(m) == 0)
-			accept_frame = 1;
-		else
-			accept_frame = 0;
 
+		accept_frame = 1;
 		prev_len_adj = 0;
 		desc_len = letoh16(desc->length);
 
diff --git a/sys/dev/pci/if_ix.c b/sys/dev/pci/if_ix.c
index 49ba560e01d..b86c61e7595 100644
--- a/sys/dev/pci/if_ix.c
+++ b/sys/dev/pci/if_ix.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_ix.c,v 1.28 2009/08/12 16:56:59 jsg Exp $	*/
+/*	$OpenBSD: if_ix.c,v 1.29 2009/08/12 20:02:42 dlg Exp $	*/
 
 /******************************************************************************
 
@@ -2631,12 +2631,10 @@ ixgbe_rxeof(struct rx_ring *rxr, int count)
 			    rxr->last_rx_desc_filled);
 		}
 
+		m_cluncount(m, 1);
 		rxr->rx_ndescs--;
-		if (m_cluncount(m) == 0)
-			accept_frame = 1;
-		else
-			accept_frame = 0;
 
+		accept_frame = 1;
 		prev_len_adj = 0;
 		desc_len = letoh16(rxdesc->wb.upper.length);
 
diff --git a/sys/kern/uipc_mbuf.c b/sys/kern/uipc_mbuf.c
index a357f84a976..26b61162ee6 100644
--- a/sys/kern/uipc_mbuf.c
+++ b/sys/kern/uipc_mbuf.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uipc_mbuf.c,v 1.131 2009/08/12 14:39:05 dlg Exp $	*/
+/*	$OpenBSD: uipc_mbuf.c,v 1.132 2009/08/12 20:02:42 dlg Exp $	*/
 /*	$NetBSD: uipc_mbuf.c,v 1.15.4.1 1996/06/13 17:11:44 cgd Exp $	*/
 
 /*
@@ -372,26 +372,20 @@ m_clcount(struct ifnet *ifp, int pi)
 	ifp->if_data.ifi_mclpool[pi].mcl_alive++;
 }
 
-int
-m_cluncount(struct mbuf *m)
+void
+m_cluncount(struct mbuf *m, int all)
 {
-	struct mbuf_ext *me = &m->m_ext;
-	int pi;
-
-	splassert(IPL_NET);
-
-	if (((m->m_flags & (M_EXT|M_CLUSTER)) != (M_EXT|M_CLUSTER)) ||
-	    (me->ext_ifp == NULL))
-		return (0);
-
-	pi = me->ext_backend;
-	me->ext_ifp->if_data.ifi_mclpool[pi].mcl_alive--;
-	me->ext_ifp = NULL;
-
-	if (mclpools[pi].pr_nitems <= mclpools[pi].pr_minitems)
-		return (1);
+	struct mbuf_ext *me;
 
-	return (0);
+	do {
+		me = &m->m_ext;
+		if (((m->m_flags & (M_EXT|M_CLUSTER)) != (M_EXT|M_CLUSTER)) ||
+		    (me->ext_ifp == NULL))
+			continue;
+
+		me->ext_ifp->if_data.ifi_mclpool[me->ext_backend].mcl_alive--;
+		me->ext_ifp = NULL;
+	} while (all && (m = m->m_next));
 }
 
 struct mbuf *
@@ -474,25 +468,21 @@ m_free(struct mbuf *m)
 void
 m_extfree(struct mbuf *m)
 {
-	struct mbuf_ext *me = &m->m_ext;
-	int pi;
-
 	if (MCLISREFERENCED(m)) {
-		me->ext_nextref->m_ext.ext_prevref = me->ext_prevref;
-		me->ext_prevref->m_ext.ext_nextref = me->ext_nextref;
+		m->m_ext.ext_nextref->m_ext.ext_prevref =
+		    m->m_ext.ext_prevref;
+		m->m_ext.ext_prevref->m_ext.ext_nextref =
+		    m->m_ext.ext_nextref;
 	} else if (m->m_flags & M_CLUSTER) {
-		pi = me->ext_backend;
-		if (me->ext_ifp != NULL) {
-			me->ext_ifp->if_data.ifi_mclpool[pi].mcl_alive--;
-			me->ext_ifp = NULL;
-		}
-		pool_put(&mclpools[pi], me->ext_buf);
-	} else if (me->ext_free)
-		me->ext_free(me->ext_buf, me->ext_size, me->ext_arg);
+		m_cluncount(m, 0);
+		pool_put(&mclpools[m->m_ext.ext_backend],
+		    m->m_ext.ext_buf);
+	} else if (m->m_ext.ext_free)
+		(*(m->m_ext.ext_free))(m->m_ext.ext_buf,
+		    m->m_ext.ext_size, m->m_ext.ext_arg);
 	else
 		panic("unknown type of extension buffer");
-
-	me->ext_size = 0;
+	m->m_ext.ext_size = 0;
 	m->m_flags &= ~(M_EXT|M_CLUSTER);
 }
 
diff --git a/sys/net/if_ethersubr.c b/sys/net/if_ethersubr.c
index ba971536e3c..a4ee764bdbe 100644
--- a/sys/net/if_ethersubr.c
+++ b/sys/net/if_ethersubr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_ethersubr.c,v 1.134 2009/08/12 14:39:05 dlg Exp $	*/
+/*	$OpenBSD: if_ethersubr.c,v 1.135 2009/08/12 20:02:42 dlg Exp $	*/
 /*	$NetBSD: if_ethersubr.c,v 1.19 1996/05/07 02:40:30 thorpej Exp $	*/
 
 /*
@@ -542,14 +542,7 @@ ether_input(ifp0, eh, m)
 	struct ether_header *eh_tmp;
 #endif
 
-	/*
-	 * the cluster is no longer on the ring, so don't count it against the
-	 * ring. if the system wants the packet back we should give it back.
-	 */
-	if (m_cluncount(m) != 0) {
-		m_freem(m);
-		return;
-	}
+	m_cluncount(m, 1);
 
 	/* mark incomming routing domain */
 	m->m_pkthdr.rdomain = ifp->if_rdomain;
diff --git a/sys/sys/mbuf.h b/sys/sys/mbuf.h
index a8b21454744..ef6e1cbbcf1 100644
--- a/sys/sys/mbuf.h
+++ b/sys/sys/mbuf.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mbuf.h,v 1.132 2009/08/12 14:39:05 dlg Exp $	*/
+/*	$OpenBSD: mbuf.h,v 1.133 2009/08/12 20:02:42 dlg Exp $	*/
 /*	$NetBSD: mbuf.h,v 1.19 1996/02/09 18:25:14 christos Exp $	*/
 
 /*
@@ -420,7 +420,7 @@ struct mbuf *m_clget(struct mbuf *, int, struct ifnet *, u_int);
 void	m_clsetwms(struct ifnet *, u_int, u_int, u_int);
 int	m_cldrop(struct ifnet *, int);
 void	m_clcount(struct ifnet *, int);
-int	m_cluncount(struct mbuf *);
+void	m_cluncount(struct mbuf *, int);
 void	m_clinitifp(struct ifnet *);
 void	m_adj(struct mbuf *, int);
 void	m_copyback(struct mbuf *, int, int, const void *);