W dniu 2010-11-19 00:24, Stuart Henderson pisze:
On 2010-11-18, RLW<seran...@o2.pl> wrote:
W dniu 2010-11-18 17:41, Claudio Jeker pisze:
No the problem is altq. Altq(4) was written when 100Mbps was common and
people shaped traffic in the low megabit range. It seems to hit a wall when
doing hundreds of megabits. Guess someone needs to run a profiling kernel
and see where all that time is spent and then optimize altq(4).
Its nice to hear from OpenBSD developer on this matter.
I am wondering who is gonna be that "someone"? ;) and when it could happen?
The "someone" running a profiling kernel to identify the hot spots could be you.
cd /sys/arch/<arch>/config
config -p<kernelname>
build a kernel from the ../compile/<kernelname>.PROF directory in the usual way
kgmon -b to start profiling
(generate some traffic)
kgmon -h to stop profiling
kgmon -p to dump stats
gprof /bsd gmon.out to read stats...
Assuming you're interested in routed traffic (rather than queuing traffic
generated on a box itself), make sure you run the traffic source and sink
on other machines routing through the altq box, don't source/sink traffic
on the altq box itself.
Hello again ;)
I finaly had time to do kernel profiling.
So we have:
- default OpenBSD 4.8 install
- em0 nic (at pci express slot)
- default sysctl
- definition of queue in pf.conf:
altq on em0 cbq bandwidth 1Gb queue { q_lan }
queue q_lan bandwidth 950Mb cbq (default)
- low speed between Linux Debian box (as iperf server) and OpenBSD box
(as iperf client):
[ ID] Interval Transfer Bandwidth
[ 3] 41.0-42.0 sec 17.1 MBytes 144 Mbits/sec
[ ID] Interval Transfer Bandwidth
[ 3] 42.0-43.0 sec 17.2 MBytes 144 Mbits/sec
[ ID] Interval Transfer Bandwidth
[ 3] 43.0-44.0 sec 17.1 MBytes 144 Mbits/sec
[ ID] Interval Transfer Bandwidth
[ 3] 44.0-45.0 sec 17.2 MBytes 144 Mbits/sec
[ ID] Interval Transfer Bandwidth
[ 3] 45.0-46.0 sec 17.2 MBytes 144 Mbits/sec
[ ID] Interval Transfer Bandwidth
[ 3] 46.0-47.0 sec 17.1 MBytes 143 Mbits/sec
[ ID] Interval Transfer Bandwidth
[ 3] 47.0-48.0 sec 17.2 MBytes 144 Mbits/sec
[ ID] Interval Transfer Bandwidth
[ 3] 48.0-49.0 sec 17.1 MBytes 144 Mbits/sec
[ ID] Interval Transfer Bandwidth
[ 3] 49.0-50.0 sec 17.1 MBytes 144 Mbits/sec
[ ID] Interval Transfer Bandwidth
[ 3] 0.0-50.0 sec 858 MBytes 144 Mbits/sec
- stats from kernel profiling at:
http://erydium.pl/upload/20101230_profiling.txt
best regards,
RLW
