net: add documentation for skb recycling
Commit 04a4bb55bcf35b63d40fd2725e58599ff8310dd7 ("net: add
skb_recycle_check() to enable netdriver skb recycling") added a
method for network drivers to recycle skbuffs, but while use of
this mechanism was documented in the commit message, it should
really have been added as a docbook comment as well -- this
patch does that.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 4e22e3a..ebb6b94 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -449,6 +449,18 @@
__kfree_skb(skb);
}
+/**
+ * skb_recycle_check - check if skb can be reused for receive
+ * @skb: buffer
+ * @skb_size: minimum receive buffer size
+ *
+ * Checks that the skb passed in is not shared or cloned, and
+ * that it is linear and its head portion at least as large as
+ * skb_size so that it can be recycled as a receive buffer.
+ * If these conditions are met, this function does any necessary
+ * reference count dropping and cleans up the skbuff as if it
+ * just came from __alloc_skb().
+ */
int skb_recycle_check(struct sk_buff *skb, int skb_size)
{
struct skb_shared_info *shinfo;