net: add skb_recycle_check() to enable netdriver skb recycling
This patch adds skb_recycle_check(), which can be used by a network
driver after transmitting an skb to check whether this skb can be
recycled as a receive buffer.
skb_recycle_check() checks that the skb is not shared or cloned, and
that it is linear and its head portion large enough (as determined by
the driver) to be recycled as a receive buffer. If these conditions
are met, it does any necessary reference count dropping and cleans
up the skbuff as if it just came from __alloc_skb().
Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index a19ea43..720b688 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -383,6 +383,8 @@
return __alloc_skb(size, priority, 1, -1);
}
+extern int skb_recycle_check(struct sk_buff *skb, int skb_size);
+
extern struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
extern struct sk_buff *skb_clone(struct sk_buff *skb,
gfp_t priority);