net: modify skb_rbtree_purge to return the truesize of all purged skbs.

Tested: see the next patch is the series.

Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Peter Oskolkov <posk@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 385114dec8a49b5e5945e77ba7de6356106713f4)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index c7cca35..724c6ab 100644 (file)
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -2418,7 +2418,7 @@ static inline void __skb_queue_purge(struct sk_buff_head *list)
                kfree_skb(skb);
 }
 
-void skb_rbtree_purge(struct rb_root *root);
+unsigned int skb_rbtree_purge(struct rb_root *root);
 
 void *netdev_alloc_frag(unsigned int fragsz);
 

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 96a553d..4e545e4 100644 (file)
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -2425,23 +2425,27 @@ EXPORT_SYMBOL(skb_queue_purge);
 /**
  *     skb_rbtree_purge - empty a skb rbtree
  *     @root: root of the rbtree to empty
+ *     Return value: the sum of truesizes of all purged skbs.
  *
  *     Delete all buffers on an &sk_buff rbtree. Each buffer is removed from
  *     the list and one reference dropped. This function does not take
  *     any lock. Synchronization should be handled by the caller (e.g., TCP
  *     out-of-order queue is protected by the socket lock).
  */
-void skb_rbtree_purge(struct rb_root *root)
+unsigned int skb_rbtree_purge(struct rb_root *root)
 {
        struct rb_node *p = rb_first(root);
+       unsigned int sum = 0;
 
        while (p) {
                struct sk_buff *skb = rb_entry(p, struct sk_buff, rbnode);
 
                p = rb_next(p);
                rb_erase(&skb->rbnode, root);
+               sum += skb->truesize;
                kfree_skb(skb);
        }
+       return sum;
 }
 
 /**