Re: [PATCH net-next] net: use skb_unref() in napi_consume_skb()

[David Miller]

From: Paolo Abeni 
Date: Wed, 14 Jun 2017 11:48:48 +0200

> The commit 83ada39bb79d ("net: factor out a helper to decrement the
> skb refcount") provided and used a helper for decrementing skb usage,
> but I missed at least a spot for it.
> 
> This change remove some more duplicated code reusing skb_unref() in
> napi_consume_skb(), too. The helper uses an additional, unneeded
> unlikely(!skb) test - napi_consume_skb() already check it a few lines
> above - but the compiler is smart enough to optimize the duplicated
> test out.
> 
> Signed-off-by: Paolo Abeni 

Applied.

[PATCH net-next] net: use skb_unref() in napi_consume_skb()

[Paolo Abeni]

The commit 83ada39bb79d ("net: factor out a helper to decrement the
skb refcount") provided and used a helper for decrementing skb usage,
but I missed at least a spot for it.

This change remove some more duplicated code reusing skb_unref() in
napi_consume_skb(), too. The helper uses an additional, unneeded
unlikely(!skb) test - napi_consume_skb() already check it a few lines
above - but the compiler is smart enough to optimize the duplicated
test out.

Signed-off-by: Paolo Abeni 
---
 net/core/skbuff.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 3046027..c4d2c1f 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -817,10 +817,9 @@ void napi_consume_skb(struct sk_buff *skb, int budget)
return;
}
 
-   if (likely(atomic_read(>users) == 1))
-   smp_rmb();
-   else if (likely(!atomic_dec_and_test(>users)))
+   if (!skb_unref(skb))
return;
+
/* if reaching here SKB is ready to free */
trace_consume_skb(skb);
 
-- 
2.9.4