[NET]: Store skb->timestamp as offset to a base timestamp

Reduces skb size by 8 bytes on 64-bit.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 29 insertions, 14 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 9d153eb1e8cf..a3ed53cc4af8 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1009,13 +1009,22 @@ void net_disable_timestamp(void)
         atomic_dec(&netstamp_needed);
 }
 
-static inline void net_timestamp(struct timeval *stamp)
+void __net_timestamp(struct sk_buff *skb)
+{
+        struct timeval tv;
+
+        do_gettimeofday(&tv);
+        skb_set_timestamp(skb, &tv);
+}
+EXPORT_SYMBOL(__net_timestamp);
+
+static inline void net_timestamp(struct sk_buff *skb)
 {
         if (atomic_read(&netstamp_needed))
-                do_gettimeofday(stamp);
+                __net_timestamp(skb);
         else {
-                stamp->tv_sec = 0;
-                stamp->tv_usec = 0;
+                skb->tstamp.off_sec = 0;
+                skb->tstamp.off_usec = 0;
         }
 }
 
@@ -1027,7 +1036,8 @@ static inline void net_timestamp(struct timeval *stamp)
 void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
 {
         struct packet_type *ptype;
-        net_timestamp(&skb->stamp);
+
+        net_timestamp(skb);
 
         rcu_read_lock();
         list_for_each_entry_rcu(ptype, &ptype_all, list) {
@@ -1379,8 +1389,8 @@ int netif_rx(struct sk_buff *skb)
         if (netpoll_rx(skb))
                 return NET_RX_DROP;
 
-        if (!skb->stamp.tv_sec)
-                net_timestamp(&skb->stamp);
+        if (!skb->tstamp.off_sec)
+                net_timestamp(skb);
 
         /*
          * The code is rearranged so that the path is the most
@@ -1566,8 +1576,8 @@ int netif_receive_skb(struct sk_buff *skb)
         if (skb->dev->poll && netpoll_rx(skb))
                 return NET_RX_DROP;
 
-        if (!skb->stamp.tv_sec)
-                net_timestamp(&skb->stamp);
+        if (!skb->tstamp.off_sec)
+                net_timestamp(skb);
 
         if (!skb->input_dev)
                 skb->input_dev = skb->dev;
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 1beb782ac41b..72ee00f7b30c 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -1217,7 +1217,7 @@ static void neigh_proxy_process(unsigned long arg)
 
         while (skb != (struct sk_buff *)&tbl->proxy_queue) {
                 struct sk_buff *back = skb;
-                long tdif = back->stamp.tv_usec - now;
+                long tdif = NEIGH_CB(back)->sched_next - now;
 
                 skb = skb->next;
                 if (tdif <= 0) {
@@ -1248,8 +1248,9 @@ void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
                 kfree_skb(skb);
                 return;
         }
-        skb->stamp.tv_sec  = LOCALLY_ENQUEUED;
-        skb->stamp.tv_usec = sched_next;
+
+        NEIGH_CB(skb)->sched_next = sched_next;
+        NEIGH_CB(skb)->flags |= LOCALLY_ENQUEUED;
 
         spin_lock(&tbl->proxy_queue.lock);
         if (del_timer(&tbl->proxy_timer)) {
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index ef498cb9f786..39a161dbc16d 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -70,6 +70,8 @@
 
 static kmem_cache_t *skbuff_head_cache;
 
+struct timeval __read_mostly skb_tv_base;
+
 /*
  *      Keep out-of-line to prevent kernel bloat.
  *      __builtin_return_address is not used because it is not always
@@ -331,7 +333,7 @@ struct sk_buff *skb_clone(struct sk_buff *skb, unsigned int __nocast gfp_mask)
 
         n->next = n->prev = NULL;
         n->sk = NULL;
-        C(stamp);
+        C(tstamp);
         C(dev);
         C(h);
         C(nh);
@@ -408,7 +410,7 @@ static void copy_skb_header(struct sk_buff *new, const struct sk_buff *old)
         memcpy(new->cb, old->cb, sizeof(old->cb));
         new->local_df   = old->local_df;
         new->pkt_type   = old->pkt_type;
-        new->stamp      = old->stamp;
+        new->tstamp     = old->tstamp;
         new->destructor = NULL;
 #ifdef CONFIG_NETFILTER
         new->nfmark     = old->nfmark;
@@ -1645,6 +1647,7 @@ void __init skb_init(void)
                                               NULL, NULL);
         if (!skbuff_head_cache)
                 panic("cannot create skbuff cache");
+        do_gettimeofday(&skb_tv_base);
 }
 
 EXPORT_SYMBOL(___pskb_trim);
@@ -1678,3 +1681,4 @@ EXPORT_SYMBOL(skb_prepare_seq_read);
 EXPORT_SYMBOL(skb_seq_read);
 EXPORT_SYMBOL(skb_abort_seq_read);
 EXPORT_SYMBOL(skb_find_text);
+EXPORT_SYMBOL(skb_tv_base);