[INET]: Generalise the TCP sock ID lookup routines

And also some TIME_WAIT functions.

[acme@toy net-2.6.14]$ grep built-in /tmp/before.size /tmp/after.size
/tmp/before.size: 282955   13122    9312  305389   4a8ed net/ipv4/built-in.o
/tmp/after.size:  281566   13122    9312  304000   4a380 net/ipv4/built-in.o
[acme@toy net-2.6.14]$

I kept them still inlined, will uninline at some point to see what
would be the performance difference.

Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

9 files changed, 188 insertions, 165 deletions

diff --git a/include/net/inet_hashtables.h b/include/net/inet_hashtables.h
index c38c637e0734..b5c0d64ea741 100644
--- a/include/net/inet_hashtables.h
+++ b/include/net/inet_hashtables.h
@@ -30,6 +30,7 @@
 #include <net/tcp_states.h>
 
 #include <asm/atomic.h>
+#include <asm/byteorder.h>
 
 /* This is for all connections with a full identity, no wildcards.
  * New scheme, half the table is for TIME_WAIT, the other half is
@@ -285,13 +286,13 @@ extern struct sock *__inet_lookup_listener(const struct hlist_head *head,
                                            const int dif);
 
 /* Optimize the common listener case. */
-static inline struct sock *inet_lookup_listener(struct inet_hashinfo *hashinfo,
-                                                const u32 daddr,
-                                                const unsigned short hnum,
-                                                const int dif)
+static inline struct sock *
+                inet_lookup_listener(struct inet_hashinfo *hashinfo,
+                                     const u32 daddr,
+                                     const unsigned short hnum, const int dif)
 {
         struct sock *sk = NULL;
-        struct hlist_head *head;
+        const struct hlist_head *head;
 
         read_lock(&hashinfo->lhash_lock);
         head = &hashinfo->listening_hash[inet_lhashfn(hnum)];
@@ -351,4 +352,70 @@ sherry_cache:
          ((*((__u32 *)&(inet_twsk(__sk)->tw_dport))) == (__ports)) &&   \
          (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif))))
 #endif /* 64-bit arch */
+
+/*
+ * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so we need
+ * not check it for lookups anymore, thanks Alexey. -DaveM
+ *
+ * Local BH must be disabled here.
+ */
+static inline struct sock *
+        __inet_lookup_established(struct inet_hashinfo *hashinfo,
+                                  const u32 saddr, const u16 sport,
+                                  const u32 daddr, const u16 hnum,
+                                  const int dif)
+{
+        INET_ADDR_COOKIE(acookie, saddr, daddr)
+        const __u32 ports = INET_COMBINED_PORTS(sport, hnum);
+        struct sock *sk;
+        const struct hlist_node *node;
+        /* Optimize here for direct hit, only listening connections can
+         * have wildcards anyways.
+         */
+        const int hash = inet_ehashfn(daddr, hnum, saddr, sport, hashinfo->ehash_size);
+        struct inet_ehash_bucket *head = &hashinfo->ehash[hash];
+
+        read_lock(&head->lock);
+        sk_for_each(sk, node, &head->chain) {
+                if (INET_MATCH(sk, acookie, saddr, daddr, ports, dif))
+                        goto hit; /* You sunk my battleship! */
+        }
+
+        /* Must check for a TIME_WAIT'er before going to listener hash. */
+        sk_for_each(sk, node, &(head + hashinfo->ehash_size)->chain) {
+                if (INET_TW_MATCH(sk, acookie, saddr, daddr, ports, dif))
+                        goto hit;
+        }
+        sk = NULL;
+out:
+        read_unlock(&head->lock);
+        return sk;
+hit:
+        sock_hold(sk);
+        goto out;
+}
+
+static inline struct sock *__inet_lookup(struct inet_hashinfo *hashinfo,
+                                         const u32 saddr, const u16 sport,
+                                         const u32 daddr, const u16 hnum,
+                                         const int dif)
+{
+        struct sock *sk = __inet_lookup_established(hashinfo, saddr, sport, daddr,
+                                                    hnum, dif);
+        return sk ? : inet_lookup_listener(hashinfo, daddr, hnum, dif);
+}
+
+static inline struct sock *inet_lookup(struct inet_hashinfo *hashinfo,
+                                       const u32 saddr, const u16 sport,
+                                       const u32 daddr, const u16 dport,
+                                       const int dif)
+{
+        struct sock *sk;
+
+        local_bh_disable();
+        sk = __inet_lookup(hashinfo, saddr, sport, daddr, ntohs(dport), dif);
+        local_bh_enable();
+
+        return sk;
+}
 #endif /* _INET_HASHTABLES_H */
diff --git a/include/net/inet_timewait_sock.h b/include/net/inet_timewait_sock.h
index ce117048f2fd..020f28058fd4 100644
--- a/include/net/inet_timewait_sock.h
+++ b/include/net/inet_timewait_sock.h
@@ -17,6 +17,7 @@
 
 #include <linux/config.h>
 
+#include <linux/ip.h>
 #include <linux/list.h>
 #include <linux/types.h>
 
@@ -32,6 +33,7 @@
 #endif
 
 struct inet_bind_bucket;
+struct inet_hashinfo;
 
 /*
  * This is a TIME_WAIT sock. It works around the memory consumption
@@ -139,4 +141,11 @@ static inline void inet_twsk_put(struct inet_timewait_sock *tw)
                 kmem_cache_free(tw->tw_prot->twsk_slab, tw);
         }
 }
+
+extern void __inet_twsk_kill(struct inet_timewait_sock *tw,
+                             struct inet_hashinfo *hashinfo);
+
+extern void __inet_twsk_hashdance(struct inet_timewait_sock *tw,
+                                  struct sock *sk,
+                                  struct inet_hashinfo *hashinfo);
 #endif  /* _INET_TIMEWAIT_SOCK_ */
diff --git a/include/net/sock.h b/include/net/sock.h
index c902c57bf2b7..bdae0a5eadf5 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -255,28 +255,28 @@ struct sock {
 /*
  * Hashed lists helper routines
  */
-static inline struct sock *__sk_head(struct hlist_head *head)
+static inline struct sock *__sk_head(const struct hlist_head *head)
 {
         return hlist_entry(head->first, struct sock, sk_node);
 }
 
-static inline struct sock *sk_head(struct hlist_head *head)
+static inline struct sock *sk_head(const struct hlist_head *head)
 {
         return hlist_empty(head) ? NULL : __sk_head(head);
 }
 
-static inline struct sock *sk_next(struct sock *sk)
+static inline struct sock *sk_next(const struct sock *sk)
 {
         return sk->sk_node.next ?
                 hlist_entry(sk->sk_node.next, struct sock, sk_node) : NULL;
 }
 
-static inline int sk_unhashed(struct sock *sk)
+static inline int sk_unhashed(const struct sock *sk)
 {
         return hlist_unhashed(&sk->sk_node);
 }
 
-static inline int sk_hashed(struct sock *sk)
+static inline int sk_hashed(const struct sock *sk)
 {
         return sk->sk_node.pprev != NULL;
 }
@@ -494,7 +494,7 @@ extern int sk_wait_data(struct sock *sk, long *timeo);
 struct request_sock_ops;
 
 /* Here is the right place to enable sock refcounting debugging */
-#define SOCK_REFCNT_DEBUG
+//#define SOCK_REFCNT_DEBUG
 
 /* Networking protocol blocks we attach to sockets.
  * socket layer -> transport layer interface
diff --git a/net/ipv4/Makefile b/net/ipv4/Makefile
index 2d8d30e83eb0..6650d18e400f 100644
--- a/net/ipv4/Makefile
+++ b/net/ipv4/Makefile
@@ -5,6 +5,7 @@
 obj-y     := route.o inetpeer.o protocol.o \
              ip_input.o ip_fragment.o ip_forward.o ip_options.o \
              ip_output.o ip_sockglue.o inet_hashtables.o \
+             inet_timewait_sock.o \
              tcp.o tcp_input.o tcp_output.o tcp_timer.o tcp_ipv4.o \
              tcp_minisocks.o tcp_cong.o \
              datagram.o raw.o udp.o arp.o icmp.o devinet.o af_inet.o igmp.o \
diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index 88fcba05b7d6..d94e962958a4 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -162,3 +162,5 @@ struct sock *__inet_lookup_listener(const struct hlist_head *head, const u32 dad
         }
         return result;
 }
+
+EXPORT_SYMBOL_GPL(__inet_lookup_listener);
diff --git a/net/ipv4/inet_timewait_sock.c b/net/ipv4/inet_timewait_sock.c
new file mode 100644
index 000000000000..d38d160faeb7
--- /dev/null
+++ b/net/ipv4/inet_timewait_sock.c
@@ -0,0 +1,83 @@
+/*
+ * INET         An implementation of the TCP/IP protocol suite for the LINUX
+ *              operating system.  INET is implemented using the  BSD Socket
+ *              interface as the means of communication with the user level.
+ *
+ *              Generic TIME_WAIT sockets functions
+ *
+ *              From code orinally in TCP
+ */
+
+#include <linux/config.h>
+
+#include <net/inet_hashtables.h>
+#include <net/inet_timewait_sock.h>
+
+/* Must be called with locally disabled BHs. */
+void __inet_twsk_kill(struct inet_timewait_sock *tw, struct inet_hashinfo *hashinfo)
+{
+        struct inet_bind_hashbucket *bhead;
+        struct inet_bind_bucket *tb;
+        /* Unlink from established hashes. */
+        struct inet_ehash_bucket *ehead = &hashinfo->ehash[tw->tw_hashent];
+
+        write_lock(&ehead->lock);
+        if (hlist_unhashed(&tw->tw_node)) {
+                write_unlock(&ehead->lock);
+                return;
+        }
+        __hlist_del(&tw->tw_node);
+        sk_node_init(&tw->tw_node);
+        write_unlock(&ehead->lock);
+
+        /* Disassociate with bind bucket. */
+        bhead = &hashinfo->bhash[inet_bhashfn(tw->tw_num, hashinfo->bhash_size)];
+        spin_lock(&bhead->lock);
+        tb = tw->tw_tb;
+        __hlist_del(&tw->tw_bind_node);
+        tw->tw_tb = NULL;
+        inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb);
+        spin_unlock(&bhead->lock);
+#ifdef SOCK_REFCNT_DEBUG
+        if (atomic_read(&tw->tw_refcnt) != 1) {
+                printk(KERN_DEBUG "%s timewait_sock %p refcnt=%d\n",
+                       tw->tw_prot->name, tw, atomic_read(&tw->tw_refcnt));
+        }
+#endif
+        inet_twsk_put(tw);
+}
+
+/*
+ * Enter the time wait state. This is called with locally disabled BH.
+ * Essentially we whip up a timewait bucket, copy the relevant info into it
+ * from the SK, and mess with hash chains and list linkage.
+ */
+void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk,
+                           struct inet_hashinfo *hashinfo)
+{
+        const struct inet_sock *inet = inet_sk(sk);
+        struct inet_ehash_bucket *ehead = &hashinfo->ehash[sk->sk_hashent];
+        struct inet_bind_hashbucket *bhead;
+        /* Step 1: Put TW into bind hash. Original socket stays there too.
+           Note, that any socket with inet->num != 0 MUST be bound in
+           binding cache, even if it is closed.
+         */
+        bhead = &hashinfo->bhash[inet_bhashfn(inet->num, hashinfo->bhash_size)];
+        spin_lock(&bhead->lock);
+        tw->tw_tb = inet->bind_hash;
+        BUG_TRAP(inet->bind_hash);
+        inet_twsk_add_bind_node(tw, &tw->tw_tb->owners);
+        spin_unlock(&bhead->lock);
+
+        write_lock(&ehead->lock);
+
+        /* Step 2: Remove SK from established hash. */
+        if (__sk_del_node_init(sk))
+                sock_prot_dec_use(sk->sk_prot);
+
+        /* Step 3: Hash TW into TIMEWAIT half of established hash table. */
+        inet_twsk_add_node(tw, &(ehead + hashinfo->ehash_size)->chain);
+        atomic_inc(&tw->tw_refcnt);
+
+        write_unlock(&ehead->lock);
+}
diff --git a/net/ipv4/tcp_diag.c b/net/ipv4/tcp_diag.c
index 6f2d6f2276b9..60c6a797cc50 100644
--- a/net/ipv4/tcp_diag.c
+++ b/net/ipv4/tcp_diag.c
@@ -174,8 +174,6 @@ nlmsg_failure:
         return -1;
 }
 
-extern struct sock *tcp_v4_lookup(u32 saddr, u16 sport, u32 daddr, u16 dport,
-                                  int dif);
 #ifdef CONFIG_IP_TCPDIAG_IPV6
 extern struct sock *tcp_v6_lookup(struct in6_addr *saddr, u16 sport,
                                   struct in6_addr *daddr, u16 dport,
@@ -197,9 +195,9 @@ static int tcpdiag_get_exact(struct sk_buff *in_skb, const struct nlmsghdr *nlh)
         struct sk_buff *rep;
 
         if (req->tcpdiag_family == AF_INET) {
-                sk = tcp_v4_lookup(req->id.tcpdiag_dst[0], req->id.tcpdiag_dport,
-                                   req->id.tcpdiag_src[0], req->id.tcpdiag_sport,
-                                   req->id.tcpdiag_if);
+                sk = inet_lookup(&tcp_hashinfo, req->id.tcpdiag_dst[0],
+                                 req->id.tcpdiag_dport, req->id.tcpdiag_src[0],
+                                 req->id.tcpdiag_sport, req->id.tcpdiag_if);
         }
 #ifdef CONFIG_IP_TCPDIAG_IPV6
         else if (req->tcpdiag_family == AF_INET6) {
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index ce423e48ebe0..e7e91e60ac74 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -238,71 +238,6 @@ void tcp_unhash(struct sock *sk)
         inet_unhash(&tcp_hashinfo, sk);
 }
 
-/* Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
- * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM
- *
- * Local BH must be disabled here.
- */
-
-static inline struct sock *__tcp_v4_lookup_established(const u32 saddr,
-                                                       const u16 sport,
-                                                       const u32 daddr,
-                                                       const u16 hnum,
-                                                       const int dif)
-{
-        struct inet_ehash_bucket *head;
-        INET_ADDR_COOKIE(acookie, saddr, daddr)
-        const __u32 ports = INET_COMBINED_PORTS(sport, hnum);
-        struct sock *sk;
-        const struct hlist_node *node;
-        /* Optimize here for direct hit, only listening connections can
-         * have wildcards anyways.
-         */
-        const int hash = inet_ehashfn(daddr, hnum, saddr, sport, tcp_hashinfo.ehash_size);
-        head = &tcp_hashinfo.ehash[hash];
-        read_lock(&head->lock);
-        sk_for_each(sk, node, &head->chain) {
-                if (INET_MATCH(sk, acookie, saddr, daddr, ports, dif))
-                        goto hit; /* You sunk my battleship! */
-        }
-
-        /* Must check for a TIME_WAIT'er before going to listener hash. */
-        sk_for_each(sk, node, &(head + tcp_hashinfo.ehash_size)->chain) {
-                if (INET_TW_MATCH(sk, acookie, saddr, daddr, ports, dif))
-                        goto hit;
-        }
-        sk = NULL;
-out:
-        read_unlock(&head->lock);
-        return sk;
-hit:
-        sock_hold(sk);
-        goto out;
-}
-
-static inline struct sock *__tcp_v4_lookup(u32 saddr, u16 sport,
-                                           u32 daddr, u16 hnum, int dif)
-{
-        struct sock *sk = __tcp_v4_lookup_established(saddr, sport,
-                                                      daddr, hnum, dif);
-
-        return sk ? : inet_lookup_listener(&tcp_hashinfo, daddr, hnum, dif);
-}
-
-inline struct sock *tcp_v4_lookup(u32 saddr, u16 sport, u32 daddr,
-                                  u16 dport, int dif)
-{
-        struct sock *sk;
-
-        local_bh_disable();
-        sk = __tcp_v4_lookup(saddr, sport, daddr, ntohs(dport), dif);
-        local_bh_enable();
-
-        return sk;
-}
-
-EXPORT_SYMBOL_GPL(tcp_v4_lookup);
-
 static inline __u32 tcp_v4_init_sequence(struct sock *sk, struct sk_buff *skb)
 {
         return secure_tcp_sequence_number(skb->nh.iph->daddr,
@@ -751,8 +686,8 @@ void tcp_v4_err(struct sk_buff *skb, u32 info)
                 return;
         }
 
-        sk = tcp_v4_lookup(iph->daddr, th->dest, iph->saddr,
-                           th->source, tcp_v4_iif(skb));
+        sk = inet_lookup(&tcp_hashinfo, iph->daddr, th->dest, iph->saddr,
+                         th->source, tcp_v4_iif(skb));
         if (!sk) {
                 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
                 return;
@@ -1359,11 +1294,9 @@ static struct sock *tcp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
         if (req)
                 return tcp_check_req(sk, skb, req, prev);
 
-        nsk = __tcp_v4_lookup_established(skb->nh.iph->saddr,
-                                          th->source,
-                                          skb->nh.iph->daddr,
-                                          ntohs(th->dest),
-                                          tcp_v4_iif(skb));
+        nsk = __inet_lookup_established(&tcp_hashinfo, skb->nh.iph->saddr,
+                                        th->source, skb->nh.iph->daddr,
+                                        ntohs(th->dest), tcp_v4_iif(skb));
 
         if (nsk) {
                 if (nsk->sk_state != TCP_TIME_WAIT) {
@@ -1505,9 +1438,9 @@ int tcp_v4_rcv(struct sk_buff *skb)
         TCP_SKB_CB(skb)->flags   = skb->nh.iph->tos;
         TCP_SKB_CB(skb)->sacked  = 0;
 
-        sk = __tcp_v4_lookup(skb->nh.iph->saddr, th->source,
-                             skb->nh.iph->daddr, ntohs(th->dest),
-                             tcp_v4_iif(skb));
+        sk = __inet_lookup(&tcp_hashinfo, skb->nh.iph->saddr, th->source,
+                           skb->nh.iph->daddr, ntohs(th->dest),
+                           tcp_v4_iif(skb));
 
         if (!sk)
                 goto no_tcp_socket;
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index 5b5a49335fbb..4112f7a6d108 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -56,42 +56,6 @@ static __inline__ int tcp_in_window(u32 seq, u32 end_seq, u32 s_win, u32 e_win)
 
 int tcp_tw_count;
 
-
-/* Must be called with locally disabled BHs. */
-static void tcp_timewait_kill(struct inet_timewait_sock *tw)
-{
-        struct inet_bind_hashbucket *bhead;
-        struct inet_bind_bucket *tb;
-        /* Unlink from established hashes. */
-        struct inet_ehash_bucket *ehead = &tcp_hashinfo.ehash[tw->tw_hashent];
-
-        write_lock(&ehead->lock);
-        if (hlist_unhashed(&tw->tw_node)) {
-                write_unlock(&ehead->lock);
-                return;
-        }
-        __hlist_del(&tw->tw_node);
-        sk_node_init(&tw->tw_node);
-        write_unlock(&ehead->lock);
-
-        /* Disassociate with bind bucket. */
-        bhead = &tcp_hashinfo.bhash[inet_bhashfn(tw->tw_num, tcp_hashinfo.bhash_size)];
-        spin_lock(&bhead->lock);
-        tb = tw->tw_tb;
-        __hlist_del(&tw->tw_bind_node);
-        tw->tw_tb = NULL;
-        inet_bind_bucket_destroy(tcp_hashinfo.bind_bucket_cachep, tb);
-        spin_unlock(&bhead->lock);
-
-#ifdef SOCK_REFCNT_DEBUG
-        if (atomic_read(&tw->tw_refcnt) != 1) {
-                printk(KERN_DEBUG "%s timewait_sock %p refcnt=%d\n",
-                       tw->tw_prot->name, tw, atomic_read(&tw->tw_refcnt));
-        }
-#endif
-        inet_twsk_put(tw);
-}
-
 /* 
  * * Main purpose of TIME-WAIT state is to close connection gracefully,
  *   when one of ends sits in LAST-ACK or CLOSING retransmitting FIN
@@ -290,40 +254,6 @@ kill:
         return TCP_TW_SUCCESS;
 }
 
-/* Enter the time wait state.  This is called with locally disabled BH.
- * Essentially we whip up a timewait bucket, copy the
- * relevant info into it from the SK, and mess with hash chains
- * and list linkage.
- */
-static void __tcp_tw_hashdance(struct sock *sk, struct inet_timewait_sock *tw)
-{
-        const struct inet_sock *inet = inet_sk(sk);
-        struct inet_ehash_bucket *ehead = &tcp_hashinfo.ehash[sk->sk_hashent];
-        struct inet_bind_hashbucket *bhead;
-        /* Step 1: Put TW into bind hash. Original socket stays there too.
-           Note, that any socket with inet->num != 0 MUST be bound in
-           binding cache, even if it is closed.
-         */
-        bhead = &tcp_hashinfo.bhash[inet_bhashfn(inet->num, tcp_hashinfo.bhash_size)];
-        spin_lock(&bhead->lock);
-        tw->tw_tb = inet->bind_hash;
-        BUG_TRAP(inet->bind_hash);
-        inet_twsk_add_bind_node(tw, &tw->tw_tb->owners);
-        spin_unlock(&bhead->lock);
-
-        write_lock(&ehead->lock);
-
-        /* Step 2: Remove SK from established hash. */
-        if (__sk_del_node_init(sk))
-                sock_prot_dec_use(sk->sk_prot);
-
-        /* Step 3: Hash TW into TIMEWAIT half of established hash table. */
-        inet_twsk_add_node(tw, &(ehead + tcp_hashinfo.ehash_size)->chain);
-        atomic_inc(&tw->tw_refcnt);
-
-        write_unlock(&ehead->lock);
-}
-
 /* 
  * Move a socket to time-wait or dead fin-wait-2 state.
  */ 
@@ -381,7 +311,7 @@ void tcp_time_wait(struct sock *sk, int state, int timeo)
                         tw->tw_ipv6only = 0;
 #endif
                 /* Linkage updates. */
-                __tcp_tw_hashdance(sk, tw);
+                __inet_twsk_hashdance(tw, sk, &tcp_hashinfo);
 
                 /* Get the TIME_WAIT timeout firing. */
                 if (timeo < rto)
@@ -448,7 +378,7 @@ rescan:
         inet_twsk_for_each_inmate(tw, node, &tcp_tw_death_row[slot]) {
                 __inet_twsk_del_dead_node(tw);
                 spin_unlock(&tw_death_lock);
-                tcp_timewait_kill(tw);
+                __inet_twsk_kill(tw, &tcp_hashinfo);
                 inet_twsk_put(tw);
                 killed++;
                 spin_lock(&tw_death_lock);
@@ -544,7 +474,7 @@ void tcp_tw_deschedule(struct inet_timewait_sock *tw)
                         del_timer(&tcp_tw_timer);
         }
         spin_unlock(&tw_death_lock);
-        tcp_timewait_kill(tw);
+        __inet_twsk_kill(tw, &tcp_hashinfo);
 }
 
 /* Short-time timewait calendar */
@@ -653,7 +583,7 @@ void tcp_twcal_tick(unsigned long dummy)
                         inet_twsk_for_each_inmate_safe(tw, node, safe,
                                                        &tcp_twcal_row[slot]) {
                                 __inet_twsk_del_dead_node(tw);
-                                tcp_timewait_kill(tw);
+                                __inet_twsk_kill(tw, &tcp_hashinfo);
                                 inet_twsk_put(tw);
                                 killed++;
                         }