From 7c90584c66cc4b033a3b684b0e0950f79e7b7166 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sat, 23 Sep 2017 12:39:12 -0700 Subject: [PATCH] net: speed up skb_rbtree_purge() As measured in my prior patch ("sch_netem: faster rb tree removal"), rbtree_postorder_for_each_entry_safe() is nice looking but much slower than using rb_next() directly, except when tree is small enough to fit in CPU caches (then the cost is the same) Also note that there is not even an increase of text size : $ size net/core/skbuff.o.before net/core/skbuff.o text data bss dec hex filename 40711 1298 0 42009 a419 net/core/skbuff.o.before 40711 1298 0 42009 a419 net/core/skbuff.o From: Eric Dumazet Signed-off-by: David S. Miller --- net/core/skbuff.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 16982de649b9..000ce735fa8d 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -2848,12 +2848,15 @@ EXPORT_SYMBOL(skb_queue_purge); */ void skb_rbtree_purge(struct rb_root *root) { - struct sk_buff *skb, *next; + struct rb_node *p = rb_first(root); - rbtree_postorder_for_each_entry_safe(skb, next, root, rbnode) + while (p) { + struct sk_buff *skb = rb_entry(p, struct sk_buff, rbnode); + + p = rb_next(p); + rb_erase(&skb->rbnode, root); kfree_skb(skb); - - *root = RB_ROOT; + } } /**