[PATCH net-next 4/4] net: prefetch the next skb in napi_skb_cache_get()

[Jason Xing <kerneljasonxing@gmail.com>]

From: Jason Xing <kernelxing@tencent.com>

After getting the current skb in napi_skb_cache_get(), the next skb in
cache is highly likely to be used soon, so prefetch would be helpful.

Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jason Xing <kernelxing@tencent.com>
---
 net/core/skbuff.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index d81ac78c32ff..5a1d123e7ef7 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -299,6 +299,8 @@ static struct sk_buff *napi_skb_cache_get(bool alloc)
 	}
 
 	skb = nc->skb_cache[--nc->skb_count];
+	if (nc->skb_count)
+		prefetch(nc->skb_cache[nc->skb_count - 1]);
 	local_unlock_nested_bh(&napi_alloc_cache.bh_lock);
 	kasan_mempool_unpoison_object(skb, skbuff_cache_size);
 
-- 
2.41.3