From 4b87cfa8f895a89a0108387b5ecae05f2bbd87ba Mon Sep 17 00:00:00 2001
From: mav <mav@FreeBSD.org>
Date: Sat, 26 Jan 2008 22:39:05 +0000
Subject: Improve multilink receive performance with fragment headers
 preallocation.

---
 sys/netgraph/ng_ppp.c | 45 +++++++++++++++++++++++----------------------
 1 file changed, 23 insertions(+), 22 deletions(-)

(limited to 'sys/netgraph/ng_ppp.c')

diff --git a/sys/netgraph/ng_ppp.c b/sys/netgraph/ng_ppp.c
index 408ba4b9..86fa186 100644
--- a/sys/netgraph/ng_ppp.c
+++ b/sys/netgraph/ng_ppp.c
@@ -217,9 +217,11 @@ struct ng_ppp_private {
 	uint8_t			vjCompHooked;		/* VJ comp hooked up? */
 	uint8_t			allLinksEqual;		/* all xmit the same? */
 	hook_p			hooks[HOOK_INDEX_MAX];	/* non-link hooks */
+	struct ng_ppp_frag	fragsmem[MP_MAX_QUEUE_LEN]; /* fragments storage */
 	TAILQ_HEAD(ng_ppp_fraglist, ng_ppp_frag)	/* fragment queue */
 				frags;
-	int			qlen;			/* fraq queue length */
+	TAILQ_HEAD(ng_ppp_fragfreelist, ng_ppp_frag)	/* free fragment queue */
+				fragsfree;
 	struct callout		fragTimer;		/* fraq queue check */
 	struct mtx		rmtx;			/* recv mutex */
 	struct mtx		xmtx;			/* xmit mutex */
@@ -496,6 +498,9 @@ ng_ppp_constructor(node_p node)
 
 	/* Initialize state */
 	TAILQ_INIT(&priv->frags);
+	TAILQ_INIT(&priv->fragsfree);
+	for (i = 0; i < MP_MAX_QUEUE_LEN; i++)
+		TAILQ_INSERT_TAIL(&priv->fragsfree, &priv->fragsmem[i], f_qent);
 	for (i = 0; i < NG_PPP_MAX_LINKS; i++)
 		priv->links[i].seq = MP_NOSEQ;
 	ng_callout_init(&priv->fragTimer);
@@ -1489,7 +1494,7 @@ ng_ppp_mp_recv(node_p node, item_p item, uint16_t proto, uint16_t linkNum)
 {
 	const priv_p priv = NG_NODE_PRIVATE(node);
 	struct ng_ppp_link *const link = &priv->links[linkNum];
-	struct ng_ppp_frag frag0, *frag = &frag0;
+	struct ng_ppp_frag *frag;
 	struct ng_ppp_frag *qent;
 	int i, diff, inserted;
 	struct mbuf *m;
@@ -1507,6 +1512,13 @@ ng_ppp_mp_recv(node_p node, item_p item, uint16_t proto, uint16_t linkNum)
 	NGI_GET_M(item, m);
 	NG_FREE_ITEM(item);
 
+	/* Get a new frag struct from the free queue */
+	if ((frag = TAILQ_FIRST(&priv->fragsfree)) == NULL) {
+		printf("No free fragments headers in ng_ppp!\n");
+		NG_FREE_M(m);
+		goto process;
+	}
+
 	/* Extract fragment information from MP header */
 	if (priv->conf.recvShortSeq) {
 		uint16_t shdr;
@@ -1564,13 +1576,8 @@ ng_ppp_mp_recv(node_p node, item_p item, uint16_t proto, uint16_t linkNum)
 			priv->mseq = alink->seq;
 	}
 
-	/* Allocate a new frag struct for the queue */
-	MALLOC(frag, struct ng_ppp_frag *, sizeof(*frag), M_NETGRAPH_PPP, M_NOWAIT);
-	if (frag == NULL) {
-		NG_FREE_M(m);
-		goto process;
-	}
-	*frag = frag0;
+	/* Remove frag struct from free queue. */
+	TAILQ_REMOVE(&priv->fragsfree, frag, f_qent);
 
 	/* Add fragment to queue, which is sorted by sequence number */
 	inserted = 0;
@@ -1583,13 +1590,12 @@ ng_ppp_mp_recv(node_p node, item_p item, uint16_t proto, uint16_t linkNum)
 		} else if (diff == 0) {	     /* should never happen! */
 			link->stats.dupFragments++;
 			NG_FREE_M(frag->data);
-			FREE(frag, M_NETGRAPH_PPP);
+			TAILQ_INSERT_HEAD(&priv->fragsfree, frag, f_qent);
 			ERROUT(EINVAL);
 		}
 	}
 	if (!inserted)
 		TAILQ_INSERT_HEAD(&priv->frags, frag, f_qent);
-	priv->qlen++;
 
 process:
 	/* Process the queue */
@@ -1693,8 +1699,7 @@ ng_ppp_get_packet(node_p node, struct mbuf **mp)
 			/* Bump MSEQ if necessary */
 			ng_ppp_bump_mseq(node, qent->seq);
 		}
-		FREE(qent, M_NETGRAPH_PPP);
-		priv->qlen--;
+		TAILQ_INSERT_HEAD(&priv->fragsfree, qent, f_qent);
 	}
 	*mp = m;
 }
@@ -1742,8 +1747,7 @@ ng_ppp_frag_trim(node_p node)
 			priv->bundleStats.dropFragments++;
 			TAILQ_REMOVE(&priv->frags, qent, f_qent);
 			NG_FREE_M(qent->data);
-			FREE(qent, M_NETGRAPH_PPP);
-			priv->qlen--;
+			TAILQ_INSERT_HEAD(&priv->fragsfree, qent, f_qent);
 			removed = 1;
 		}
 	}
@@ -1760,7 +1764,7 @@ ng_ppp_frag_drop(node_p node)
 	const priv_p priv = NG_NODE_PRIVATE(node);
 
 	/* Check queue length */
-	if (priv->qlen > MP_MAX_QUEUE_LEN) {
+	if (TAILQ_EMPTY(&priv->fragsfree)) {
 		struct ng_ppp_frag *qent;
 
 		/* Get oldest fragment */
@@ -1775,8 +1779,7 @@ ng_ppp_frag_drop(node_p node)
 		priv->bundleStats.dropFragments++;
 		TAILQ_REMOVE(&priv->frags, qent, f_qent);
 		NG_FREE_M(qent->data);
-		FREE(qent, M_NETGRAPH_PPP);
-		priv->qlen--;
+		TAILQ_INSERT_HEAD(&priv->fragsfree, qent, f_qent);
 
 		return (1);
 	}
@@ -1894,8 +1897,7 @@ ng_ppp_frag_checkstale(node_p node)
 			priv->bundleStats.dropFragments++;
 			TAILQ_REMOVE(&priv->frags, qent, f_qent);
 			NG_FREE_M(qent->data);
-			FREE(qent, M_NETGRAPH_PPP);
-			priv->qlen--;
+			TAILQ_INSERT_HEAD(&priv->fragsfree, qent, f_qent);
 		}
 
 		/* Extract completed packet */
@@ -2548,10 +2550,9 @@ ng_ppp_frag_reset(node_p node)
 	for (qent = TAILQ_FIRST(&priv->frags); qent; qent = qnext) {
 		qnext = TAILQ_NEXT(qent, f_qent);
 		NG_FREE_M(qent->data);
-		FREE(qent, M_NETGRAPH_PPP);
+		TAILQ_INSERT_HEAD(&priv->fragsfree, qent, f_qent);
 	}
 	TAILQ_INIT(&priv->frags);
-	priv->qlen = 0;
 }
 
 /*
-- 
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