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

On Mon, 2017-09-25 at 10:14 -0600, David Ahern wrote:

Thanks for the test.

I made a simple program this morning and ran it under perf. With the
above suggestion the rb_erase has a high cost because it always deletes
the root node. Your method 1 has a high cost on rb_first which is
expected given its definition and it is run on each removal. Both
options increase in time with the number of entries in the tree.

Your method 2 is fairly constant from 10,000 entries to 10M entries
which makes sense: a one time cost at finding rb_first and then always
removing a bottom node so rb_erase is light.

As for the change:

Acked-by: David Ahern <redacted>

Thanks a lot for double checking !