35-40% performance drop releng9 vs releng10 openvpn

[Mike Tancsa]

On 3/18/2015 5:14 PM, John-Mark Gurney wrote:
> # dtrace -x stackframes=100 -n 'profile-997 /arg0/ { @[stack()] = count(); } tick-60s { exit(0); }' -o out.kern_stacks
>
> Also, another thing you can do is to compare the two using differential
> flame graphs:
> http://www.brendangregg.com/blog/2014-11-09/differential-flame-graphs.html
>
> Which will highlight where the performances differ...

OK, some more data points.  It seems a performance regression happened 
in RELENG_10 somewhere between r277684 (late January 2015) and now. 
Using r277684 on RELENG_10, I can get about 75Mb/s of throughput on 
OpenVPN. Still not as good as the 83-85Mb on RELENG_9, but much better 
than the 61Mb using RELENG_10 from the start of this week,

For the differential graph, see

http://tancsa.com/diffgraph.svg

and

http://tancsa.com/10-r277684.svg
http://tancsa.com/10-r277684-kern.svg

	---Mike




-- 
-------------------
Mike Tancsa, tel +1 519 651 3400
Sentex Communications, mike at sentex.net
Providing Internet services since 1994 www.sentex.net
Cambridge, Ontario Canada   http://www.tancsa.com/