gro: Remember number of held packets instead of counting every time

This patch prepares for the move of the same_flow checks out of
dev_gro_receive.  As such we need to remember the number of held
packets since doing a loop just to count them every time is silly.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 10 insertions, 5 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 864519e585fc..9ee344bc6c13 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -314,6 +314,9 @@ struct napi_struct {
         spinlock_t              poll_lock;
         int                     poll_owner;
 #endif
+
+        unsigned int            gro_count;
+
         struct net_device       *dev;
         struct list_head        dev_list;
         struct sk_buff          *gro_list;
diff --git a/net/core/dev.c b/net/core/dev.c
index 709a9a922258..ae0b66936abe 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2372,6 +2372,7 @@ void napi_gro_flush(struct napi_struct *napi)
                 napi_gro_complete(skb);
         }
 
+        napi->gro_count = 0;
         napi->gro_list = NULL;
 }
 EXPORT_SYMBOL(napi_gro_flush);
@@ -2402,7 +2403,6 @@ int dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
         struct packet_type *ptype;
         __be16 type = skb->protocol;
         struct list_head *head = &ptype_base[ntohs(type) & PTYPE_HASH_MASK];
-        int count = 0;
         int same_flow;
         int mac_len;
         int ret;
@@ -2430,8 +2430,6 @@ int dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
                 NAPI_GRO_CB(skb)->free = 0;
 
                 for (p = napi->gro_list; p; p = p->next) {
-                        count++;
-
                         if (!NAPI_GRO_CB(p)->same_flow)
                                 continue;
 
@@ -2457,15 +2455,16 @@ int dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
                 *pp = nskb->next;
                 nskb->next = NULL;
                 napi_gro_complete(nskb);
-                count--;
+                napi->gro_count--;
         }
 
         if (same_flow)
                 goto ok;
 
-        if (NAPI_GRO_CB(skb)->flush || count >= MAX_GRO_SKBS)
+        if (NAPI_GRO_CB(skb)->flush || napi->gro_count >= MAX_GRO_SKBS)
                 goto normal;
 
+        napi->gro_count++;
         NAPI_GRO_CB(skb)->count = 1;
         skb_shinfo(skb)->gso_size = skb_gro_len(skb);
         skb->next = napi->gro_list;
@@ -2713,6 +2712,7 @@ void netif_napi_add(struct net_device *dev, struct napi_struct *napi,
                     int (*poll)(struct napi_struct *, int), int weight)
 {
         INIT_LIST_HEAD(&napi->poll_list);
+        napi->gro_count = 0;
         napi->gro_list = NULL;
         napi->skb = NULL;
         napi->poll = poll;
@@ -2741,6 +2741,7 @@ void netif_napi_del(struct napi_struct *napi)
         }
 
         napi->gro_list = NULL;
+        napi->gro_count = 0;
 }
 EXPORT_SYMBOL(netif_napi_del);
 
@@ -5246,6 +5247,7 @@ static int __init net_dev_init(void)
                 queue->backlog.poll = process_backlog;
                 queue->backlog.weight = weight_p;
                 queue->backlog.gro_list = NULL;
+                queue->backlog.gro_count = 0;
         }
 
         dev_boot_phase = 0;