net: fix napi_reuse_skb() skb reserve
napi->skb is allocated in napi_get_frags() using
netdev_alloc_skb_ip_align(), with a reserve of NET_SKB_PAD +
NET_IP_ALIGN bytes.
However, when such skb is recycled in napi_reuse_skb(), it ends with a
reserve of NET_IP_ALIGN which is suboptimal.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index 0f3eb7d..452db70 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3560,7 +3560,8 @@
static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb)
{
__skb_pull(skb, skb_headlen(skb));
- skb_reserve(skb, NET_IP_ALIGN - skb_headroom(skb));
+ /* restore the reserve we had after netdev_alloc_skb_ip_align() */
+ skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN - skb_headroom(skb));
skb->vlan_tci = 0;
skb->dev = napi->dev;
skb->skb_iif = 0;