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authorthorpej <thorpej@NetBSD.org>2001-09-11 21:03:20 +0000
committerthorpej <thorpej@NetBSD.org>2001-09-11 21:03:20 +0000
commit050e9de009c01a44dff7ef5555ebe3b32d366174 (patch)
tree37a65711a769487b5d6a85e4794c8be32ddd5a0a /sys
parent0f63dc99dc35250eab88ae4ee75772a990f637ac (diff)
Use callouts for SYN cache timers, rather than traversing time queues
in tcp_slowtimo().
Diffstat (limited to 'sys')
-rw-r--r--sys/netinet/tcp_input.c178
-rw-r--r--sys/netinet/tcp_subr.c3
-rw-r--r--sys/netinet/tcp_timer.c7
-rw-r--r--sys/netinet/tcp_var.h18
4 files changed, 86 insertions, 120 deletions
diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c
index bd31f5b338f..a78e07b8a7d 100644
--- a/sys/netinet/tcp_input.c
+++ b/sys/netinet/tcp_input.c
@@ -1,4 +1,4 @@
-/* $NetBSD: tcp_input.c,v 1.129 2001/09/10 22:14:26 thorpej Exp $ */
+/* $NetBSD: tcp_input.c,v 1.130 2001/09/11 21:03:20 thorpej Exp $ */
/*
%%% portions-copyright-nrl-95
@@ -2578,18 +2578,19 @@ do { \
default: \
hash = 0; \
} \
-} while (0)
+} while (/*CONSTCOND*/0)
#endif /* INET6 */
#define SYN_CACHE_RM(sc) \
do { \
- LIST_REMOVE((sc), sc_bucketq); \
+ TAILQ_REMOVE(&tcp_syn_cache[(sc)->sc_bucketidx].sch_bucket, \
+ (sc), sc_bucketq); \
(sc)->sc_tp = NULL; \
LIST_REMOVE((sc), sc_tpq); \
tcp_syn_cache[(sc)->sc_bucketidx].sch_length--; \
- TAILQ_REMOVE(&tcp_syn_cache_timeq[(sc)->sc_rxtshift], (sc), sc_timeq); \
+ callout_stop(&(sc)->sc_timer); \
syn_cache_count--; \
-} while (0)
+} while (/*CONSTCOND*/0)
#define SYN_CACHE_PUT(sc) \
do { \
@@ -2598,24 +2599,22 @@ do { \
if ((sc)->sc_route4.ro_rt != NULL) \
RTFREE((sc)->sc_route4.ro_rt); \
pool_put(&syn_cache_pool, (sc)); \
-} while (0)
+} while (/*CONSTCOND*/0)
struct pool syn_cache_pool;
/*
* We don't estimate RTT with SYNs, so each packet starts with the default
- * RTT and each timer queue has a fixed timeout value. This allows us to
- * optimize the timer queues somewhat.
+ * RTT and each timer step has a fixed timeout value.
*/
#define SYN_CACHE_TIMER_ARM(sc) \
do { \
TCPT_RANGESET((sc)->sc_rxtcur, \
TCPTV_SRTTDFLT * tcp_backoff[(sc)->sc_rxtshift], TCPTV_MIN, \
TCPTV_REXMTMAX); \
- PRT_SLOW_ARM((sc)->sc_rexmt, (sc)->sc_rxtcur); \
-} while (0)
-
-TAILQ_HEAD(, syn_cache) tcp_syn_cache_timeq[TCP_MAXRXTSHIFT + 1];
+ callout_reset(&(sc)->sc_timer, \
+ (sc)->sc_rxtcur * (hz / PR_SLOWHZ), syn_cache_timer, (sc)); \
+} while (/*CONSTCOND*/0)
#define SYN_CACHE_TIMESTAMP(sc) (tcp_now - (sc)->sc_timebase)
@@ -2626,11 +2625,7 @@ syn_cache_init()
/* Initialize the hash buckets. */
for (i = 0; i < tcp_syn_cache_size; i++)
- LIST_INIT(&tcp_syn_cache[i].sch_bucket);
-
- /* Initialize the timer queues. */
- for (i = 0; i <= TCP_MAXRXTSHIFT; i++)
- TAILQ_INIT(&tcp_syn_cache_timeq[i]);
+ TAILQ_INIT(&tcp_syn_cache[i].sch_bucket);
/* Initialize the syn cache pool. */
pool_init(&syn_cache_pool, sizeof(struct syn_cache), 0, 0, 0,
@@ -2644,7 +2639,7 @@ syn_cache_insert(sc, tp)
{
struct syn_cache_head *scp;
struct syn_cache *sc2;
- int s, i;
+ int s;
/*
* If there are no entries in the hash table, reinitialize
@@ -2670,72 +2665,67 @@ syn_cache_insert(sc, tp)
tcpstat.tcps_sc_bucketoverflow++;
/*
* The bucket is full. Toss the oldest element in the
- * bucket. This will be the entry with our bucket
- * index closest to the front of the timer queue with
- * the largest timeout value.
- *
- * Note: This timer queue traversal may be expensive, so
- * we hope that this doesn't happen very often. It is
- * much more likely that we'll overflow the entire
- * cache, which is much easier to handle; see below.
+ * bucket. This will be the first entry in the bucket.
*/
- for (i = TCP_MAXRXTSHIFT; i >= 0; i--) {
- for (sc2 = TAILQ_FIRST(&tcp_syn_cache_timeq[i]);
- sc2 != NULL;
- sc2 = TAILQ_NEXT(sc2, sc_timeq)) {
- if (sc2->sc_bucketidx == sc->sc_bucketidx) {
- SYN_CACHE_RM(sc2);
- SYN_CACHE_PUT(sc2);
- goto insert; /* 2 level break */
- }
- }
- }
+ sc2 = TAILQ_FIRST(&scp->sch_bucket);
#ifdef DIAGNOSTIC
/*
* This should never happen; we should always find an
* entry in our bucket.
*/
- panic("syn_cache_insert: bucketoverflow: impossible");
+ if (sc2 == NULL)
+ panic("syn_cache_insert: bucketoverflow: impossible");
#endif
+ SYN_CACHE_RM(sc2);
+ SYN_CACHE_PUT(sc2);
} else if (syn_cache_count >= tcp_syn_cache_limit) {
+ struct syn_cache_head *scp2, *sce;
+
tcpstat.tcps_sc_overflowed++;
/*
* The cache is full. Toss the oldest entry in the
- * entire cache. This is the front entry in the
- * first non-empty timer queue with the largest
- * timeout value.
+ * first non-empty bucket we can find.
+ *
+ * XXX We would really like to toss the oldest
+ * entry in the cache, but we hope that this
+ * condition doesn't happen very often.
*/
- for (i = TCP_MAXRXTSHIFT; i >= 0; i--) {
- sc2 = TAILQ_FIRST(&tcp_syn_cache_timeq[i]);
- if (sc2 == NULL)
- continue;
- SYN_CACHE_RM(sc2);
- SYN_CACHE_PUT(sc2);
- goto insert; /* symmetry with above */
- }
+ scp2 = scp;
+ if (TAILQ_EMPTY(&scp2->sch_bucket)) {
+ sce = &tcp_syn_cache[tcp_syn_cache_size];
+ for (++scp2; scp2 != scp; scp2++) {
+ if (scp2 >= sce)
+ scp2 = &tcp_syn_cache[0];
+ if (! TAILQ_EMPTY(&scp2->sch_bucket))
+ break;
+ }
#ifdef DIAGNOSTIC
- /*
- * This should never happen; we should always find an
- * entry in the cache.
- */
- panic("syn_cache_insert: cache overflow: impossible");
+ /*
+ * This should never happen; we should always find a
+ * non-empty bucket.
+ */
+ if (scp2 == scp)
+ panic("syn_cache_insert: cacheoverflow: "
+ "impossible");
#endif
+ }
+ sc2 = TAILQ_FIRST(&scp2->sch_bucket);
+ SYN_CACHE_RM(sc2);
+ SYN_CACHE_PUT(sc2);
}
- insert:
/*
* Initialize the entry's timer.
*/
sc->sc_rxttot = 0;
sc->sc_rxtshift = 0;
SYN_CACHE_TIMER_ARM(sc);
- TAILQ_INSERT_TAIL(&tcp_syn_cache_timeq[sc->sc_rxtshift], sc, sc_timeq);
/* Link it from tcpcb entry */
LIST_INSERT_HEAD(&tp->t_sc, sc, sc_tpq);
/* Put it into the bucket. */
- LIST_INSERT_HEAD(&scp->sch_bucket, sc, sc_bucketq);
+ TAILQ_INSERT_TAIL(&scp->sch_bucket, sc, sc_bucketq);
scp->sch_length++;
syn_cache_count++;
@@ -2749,60 +2739,41 @@ syn_cache_insert(sc, tp)
* that entry.
*/
void
-syn_cache_timer()
+syn_cache_timer(void *arg)
{
- struct syn_cache *sc, *nsc;
- int i, s;
+ struct syn_cache *sc = arg;
+ int s;
s = splsoftnet();
+ if (__predict_false(sc->sc_rxtshift == TCP_MAXRXTSHIFT)) {
+ /* Drop it -- too many retransmissions. */
+ goto dropit;
+ }
+
/*
- * First, get all the entries that need to be retransmitted, or
- * must be expired due to exceeding the initial keepalive time.
+ * Compute the total amount of time this entry has
+ * been on a queue. If this entry has been on longer
+ * than the keep alive timer would allow, expire it.
*/
- for (i = 0; i < TCP_MAXRXTSHIFT; i++) {
- for (sc = TAILQ_FIRST(&tcp_syn_cache_timeq[i]);
- sc != NULL && PRT_SLOW_ISEXPIRED(sc->sc_rexmt);
- sc = nsc) {
- nsc = TAILQ_NEXT(sc, sc_timeq);
+ sc->sc_rxttot += sc->sc_rxtcur;
+ if (sc->sc_rxttot >= TCPTV_KEEP_INIT)
+ goto dropit;
- /*
- * Compute the total amount of time this entry has
- * been on a queue. If this entry has been on longer
- * than the keep alive timer would allow, expire it.
- */
- sc->sc_rxttot += sc->sc_rxtcur;
- if (sc->sc_rxttot >= TCPTV_KEEP_INIT) {
- tcpstat.tcps_sc_timed_out++;
- SYN_CACHE_RM(sc);
- SYN_CACHE_PUT(sc);
- continue;
- }
+ tcpstat.tcps_sc_retransmitted++;
+ (void) syn_cache_respond(sc, NULL);
- tcpstat.tcps_sc_retransmitted++;
- (void) syn_cache_respond(sc, NULL);
+ /* Advance the timer back-off. */
+ sc->sc_rxtshift++;
+ SYN_CACHE_TIMER_ARM(sc);
- /* Advance this entry onto the next timer queue. */
- TAILQ_REMOVE(&tcp_syn_cache_timeq[i], sc, sc_timeq);
- sc->sc_rxtshift = i + 1;
- SYN_CACHE_TIMER_ARM(sc);
- TAILQ_INSERT_TAIL(&tcp_syn_cache_timeq[sc->sc_rxtshift],
- sc, sc_timeq);
- }
- }
+ splx(s);
+ return;
- /*
- * Now get all the entries that are expired due to too many
- * retransmissions.
- */
- for (sc = TAILQ_FIRST(&tcp_syn_cache_timeq[TCP_MAXRXTSHIFT]);
- sc != NULL && PRT_SLOW_ISEXPIRED(sc->sc_rexmt);
- sc = nsc) {
- nsc = TAILQ_NEXT(sc, sc_timeq);
- tcpstat.tcps_sc_timed_out++;
- SYN_CACHE_RM(sc);
- SYN_CACHE_PUT(sc);
- }
+ dropit:
+ tcpstat.tcps_sc_timed_out++;
+ SYN_CACHE_RM(sc);
+ SYN_CACHE_PUT(sc);
splx(s);
}
@@ -2855,8 +2826,8 @@ syn_cache_lookup(src, dst, headp)
scp = &tcp_syn_cache[hash % tcp_syn_cache_size];
*headp = scp;
s = splsoftnet();
- for (sc = LIST_FIRST(&scp->sch_bucket); sc != NULL;
- sc = LIST_NEXT(sc, sc_bucketq)) {
+ for (sc = TAILQ_FIRST(&scp->sch_bucket); sc != NULL;
+ sc = TAILQ_NEXT(sc, sc_bucketq)) {
if (sc->sc_hash != hash)
continue;
if (!bcmp(&sc->sc_src, src, src->sa_len) &&
@@ -3347,6 +3318,7 @@ syn_cache_add(src, dst, th, hlen, so, m, optp, optlen, oi)
* Fill in the cache, and put the necessary IP and TCP
* options into the reply.
*/
+ callout_init(&sc->sc_timer);
bzero(sc, sizeof(struct syn_cache));
bcopy(src, &sc->sc_src, src->sa_len);
bcopy(dst, &sc->sc_dst, dst->sa_len);
diff --git a/sys/netinet/tcp_subr.c b/sys/netinet/tcp_subr.c
index 1d7040323d3..8279cf24f70 100644
--- a/sys/netinet/tcp_subr.c
+++ b/sys/netinet/tcp_subr.c
@@ -1,4 +1,4 @@
-/* $NetBSD: tcp_subr.c,v 1.118 2001/09/10 22:14:27 thorpej Exp $ */
+/* $NetBSD: tcp_subr.c,v 1.119 2001/09/11 21:03:21 thorpej Exp $ */
/*
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -194,7 +194,6 @@ int tcp_syn_cache_size = TCP_SYN_HASH_SIZE;
int tcp_syn_cache_limit = TCP_SYN_HASH_SIZE*TCP_SYN_BUCKET_SIZE;
int tcp_syn_bucket_limit = 3*TCP_SYN_BUCKET_SIZE;
struct syn_cache_head tcp_syn_cache[TCP_SYN_HASH_SIZE];
-int tcp_syn_cache_interval = 1; /* runs timer twice a second */
int tcp_freeq __P((struct tcpcb *));
diff --git a/sys/netinet/tcp_timer.c b/sys/netinet/tcp_timer.c
index c1584297f57..3f007274327 100644
--- a/sys/netinet/tcp_timer.c
+++ b/sys/netinet/tcp_timer.c
@@ -1,4 +1,4 @@
-/* $NetBSD: tcp_timer.c,v 1.54 2001/09/10 22:45:46 thorpej Exp $ */
+/* $NetBSD: tcp_timer.c,v 1.55 2001/09/11 21:03:21 thorpej Exp $ */
/*
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -221,17 +221,12 @@ tcp_delack(void *arg)
void
tcp_slowtimo()
{
- static int syn_cache_last = 0;
int s;
s = splsoftnet();
tcp_maxidle = tcp_keepcnt * tcp_keepintvl;
tcp_iss_seq += TCP_ISSINCR; /* increment iss */
tcp_now++; /* for timestamps */
- if (++syn_cache_last >= tcp_syn_cache_interval) {
- syn_cache_timer();
- syn_cache_last = 0;
- }
splx(s);
}
diff --git a/sys/netinet/tcp_var.h b/sys/netinet/tcp_var.h
index 75b9f25c4ae..12b87c18e92 100644
--- a/sys/netinet/tcp_var.h
+++ b/sys/netinet/tcp_var.h
@@ -1,4 +1,4 @@
-/* $NetBSD: tcp_var.h,v 1.86 2001/09/10 22:14:28 thorpej Exp $ */
+/* $NetBSD: tcp_var.h,v 1.87 2001/09/11 21:03:21 thorpej Exp $ */
/*
%%% portions-copyright-nrl-98
@@ -352,8 +352,8 @@ union syn_cache_sa {
};
struct syn_cache {
- LIST_ENTRY(syn_cache) sc_bucketq; /* link on bucket list */
- TAILQ_ENTRY(syn_cache) sc_timeq; /* link on timer queue */
+ TAILQ_ENTRY(syn_cache) sc_bucketq; /* link on bucket list */
+ struct callout sc_timer; /* rexmt timer */
union { /* cached route */
struct route route4;
#ifdef INET6
@@ -373,7 +373,6 @@ struct syn_cache {
union syn_cache_sa sc_dst;
tcp_seq sc_irs;
tcp_seq sc_iss;
- u_int sc_rexmt; /* retransmit timer */
u_int sc_rxtcur; /* current rxt timeout */
u_int sc_rxttot; /* total time spend on queues */
u_short sc_rxtshift; /* for computing backoff */
@@ -393,7 +392,7 @@ struct syn_cache {
};
struct syn_cache_head {
- LIST_HEAD(, syn_cache) sch_bucket; /* bucket entries */
+ TAILQ_HEAD(, syn_cache) sch_bucket; /* bucket entries */
u_short sch_length; /* # entries in bucket */
};
@@ -537,7 +536,9 @@ struct tcpstat {
#define TCPCTL_MSSDFLT 4 /* default seg size */
#define TCPCTL_SYN_CACHE_LIMIT 5 /* max size of comp. state engine */
#define TCPCTL_SYN_BUCKET_LIMIT 6 /* max size of hash bucket */
+#if 0 /*obsoleted*/
#define TCPCTL_SYN_CACHE_INTER 7 /* interval of comp. state timer */
+#endif
#define TCPCTL_INIT_WIN 8 /* initial window */
#define TCPCTL_MSS_IFMTU 9 /* mss from interface, not in_maxmtu */
#define TCPCTL_SACK 10 /* RFC2018 selective acknowledgement */
@@ -568,7 +569,7 @@ struct tcpstat {
{ "mssdflt", CTLTYPE_INT }, \
{ "syn_cache_limit", CTLTYPE_INT }, \
{ "syn_bucket_limit", CTLTYPE_INT }, \
- { "syn_cache_interval", CTLTYPE_INT },\
+ { 0, 0 },\
{ "init_win", CTLTYPE_INT }, \
{ "mss_ifmtu", CTLTYPE_INT }, \
{ "sack", CTLTYPE_INT }, \
@@ -610,7 +611,6 @@ extern int tcp_cwm_burstsize; /* burst size allowed by CWM */
extern int tcp_ack_on_push; /* ACK immediately on PUSH */
extern int tcp_syn_cache_limit; /* max entries for compressed state engine */
extern int tcp_syn_bucket_limit;/* max entries per hash bucket */
-extern int tcp_syn_cache_interval; /* compressed state timer */
extern int tcp_log_refused; /* log refused connections */
extern int tcp_rst_ppslim;
@@ -627,7 +627,7 @@ extern u_long syn_cache_count;
{ 1, 0, &tcp_mssdflt }, \
{ 1, 0, &tcp_syn_cache_limit }, \
{ 1, 0, &tcp_syn_bucket_limit }, \
- { 1, 0, &tcp_syn_cache_interval }, \
+ { 0 }, \
{ 1, 0, &tcp_init_win }, \
{ 1, 0, &tcp_mss_ifmtu }, \
{ 1, 0, &tcp_do_sack }, \
@@ -720,7 +720,7 @@ struct syn_cache *syn_cache_lookup __P((struct sockaddr *, struct sockaddr *,
void syn_cache_reset __P((struct sockaddr *, struct sockaddr *,
struct tcphdr *));
int syn_cache_respond __P((struct syn_cache *, struct mbuf *));
-void syn_cache_timer __P((void));
+void syn_cache_timer __P((void *));
void syn_cache_cleanup __P((struct tcpcb *));
int tcp_newreno __P((struct tcpcb *, struct tcphdr *));