net: speed up skb_rbtree_purge()
authorEric Dumazet <edumazet@google.com>
Sat, 23 Sep 2017 19:39:12 +0000 (12:39 -0700)
committerDavid S. Miller <davem@davemloft.net>
Tue, 26 Sep 2017 03:35:11 +0000 (20:35 -0700)
commit7c90584c66cc4b033a3b684b0e0950f79e7b7166
tree884ffbcadfd487468650145f79ab702716c4a7d4
parent3aa605f28b0d004a640a826380b39c7dcf70195d
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 <edumazet@google.com>

Signed-off-by: David S. Miller <davem@davemloft.net>
net/core/skbuff.c