Re: [PATCH net-next] sch_netem: faster rb tree removal

From: Eric Dumazet <redacted>
Date: Sat, 23 Sep 2017 11:07:28 -0700

From: Eric Dumazet <edumazet@google.com>

While running TCP tests involving netem storing millions of packets,
I had the idea to speed up tfifo_reset() and did experiments.

I tried the rbtree_postorder_for_each_entry_safe() method that is
used in skb_rbtree_purge() but discovered it was slower than the
current tfifo_reset() method.

I measured time taken to release skbs with three occupation levels :
10^4, 10^5 and 10^6 skbs with three methods :

 ...

Results :

 ...

I will also change skb_rbtree_purge() in a second patch.

Signed-off-by: Eric Dumazet <edumazet@google.com>

Applied, thanks Eric.