Network Drop Monitor: Adding kfree_skb_clean for non-drops and modifying end-of-line...
Neil Horman [Wed, 11 Mar 2009 09:49:55 +0000 (09:49 +0000)]
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>

 include/linux/skbuff.h |    4 +++-
 net/core/datagram.c    |    2 +-
 net/core/skbuff.c      |   22 ++++++++++++++++++++++
 net/ipv4/arp.c         |    2 +-
 net/ipv4/udp.c         |    2 +-
 net/packet/af_packet.c |    2 +-
 6 files changed, 29 insertions(+), 5 deletions(-)
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/skbuff.h
net/core/datagram.c
net/core/skbuff.c
net/ipv4/arp.c
net/ipv4/udp.c
net/packet/af_packet.c

index 1f659e8..1fbab2a 100644 (file)
@@ -421,6 +421,7 @@ extern void skb_dma_unmap(struct device *dev, struct sk_buff *skb,
 #endif
 
 extern void kfree_skb(struct sk_buff *skb);
+extern void consume_skb(struct sk_buff *skb);
 extern void           __kfree_skb(struct sk_buff *skb);
 extern struct sk_buff *__alloc_skb(unsigned int size,
                                   gfp_t priority, int fclone, int node);
@@ -459,7 +460,8 @@ extern int         skb_to_sgvec(struct sk_buff *skb,
 extern int            skb_cow_data(struct sk_buff *skb, int tailbits,
                                    struct sk_buff **trailer);
 extern int            skb_pad(struct sk_buff *skb, int pad);
-#define dev_kfree_skb(a)       kfree_skb(a)
+#define dev_kfree_skb(a)       consume_skb(a)
+#define dev_consume_skb(a)     kfree_skb_clean(a)
 extern void          skb_over_panic(struct sk_buff *skb, int len,
                                     void *here);
 extern void          skb_under_panic(struct sk_buff *skb, int len,
index 5e2ac0c..d0de644 100644 (file)
@@ -208,7 +208,7 @@ struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags,
 
 void skb_free_datagram(struct sock *sk, struct sk_buff *skb)
 {
-       kfree_skb(skb);
+       consume_skb(skb);
        sk_mem_reclaim_partial(sk);
 }
 
index e5e2111..6acbf9e 100644 (file)
@@ -65,6 +65,7 @@
 
 #include <asm/uaccess.h>
 #include <asm/system.h>
+#include <trace/skb.h>
 
 #include "kmap_skb.h"
 
@@ -442,11 +443,32 @@ void kfree_skb(struct sk_buff *skb)
                smp_rmb();
        else if (likely(!atomic_dec_and_test(&skb->users)))
                return;
+       trace_kfree_skb(skb, __builtin_return_address(0));
        __kfree_skb(skb);
 }
 EXPORT_SYMBOL(kfree_skb);
 
 /**
+ *     consume_skb - free an skbuff
+ *     @skb: buffer to free
+ *
+ *     Drop a ref to the buffer and free it if the usage count has hit zero
+ *     Functions identically to kfree_skb, but kfree_skb assumes that the frame
+ *     is being dropped after a failure and notes that
+ */
+void consume_skb(struct sk_buff *skb)
+{
+       if (unlikely(!skb))
+               return;
+       if (likely(atomic_read(&skb->users) == 1))
+               smp_rmb();
+       else if (likely(!atomic_dec_and_test(&skb->users)))
+               return;
+       __kfree_skb(skb);
+}
+EXPORT_SYMBOL(consume_skb);
+
+/**
  *     skb_recycle_check - check if skb can be reused for receive
  *     @skb: buffer
  *     @skb_size: minimum receive buffer size
index 3d67d1f..9c22032 100644 (file)
@@ -892,7 +892,7 @@ static int arp_process(struct sk_buff *skb)
 out:
        if (in_dev)
                in_dev_put(in_dev);
-       kfree_skb(skb);
+       consume_skb(skb);
        return 0;
 }
 
index 4bd178a..05b7abb 100644 (file)
@@ -1184,7 +1184,7 @@ static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
                        sk = sknext;
                } while (sknext);
        } else
-               kfree_skb(skb);
+               consume_skb(skb);
        spin_unlock(&hslot->lock);
        return 0;
 }
index d8cc006..74776de 100644 (file)
@@ -584,7 +584,7 @@ drop_n_restore:
                skb->len = skb_len;
        }
 drop:
-       kfree_skb(skb);
+       consume_skb(skb);
        return 0;
 }