[PATCH v3 22/30] net: modify skb_rbtree_purge to return the truesize of all purged skbs.

Stephen Hemminger
2018-09-13T14:58:54Z

From: Peter Oskolkov <posk@google.com>

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)
---
include/linux/skbuff.h | 2 +-
net/core/skbuff.c | 6 +++++-
2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index f4749678b7ee..9c8457375aee 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -2581,7 +2581,7 @@ 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 c7c5f05f2af1..8fd690def5c1 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -2842,23 +2842,27 @@ 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;
}

/**
--
2.18.0