W dniu 2010-11-16 16:14, Joel Sing pisze:
On Tuesday 16 November 2010, Robert Lewandowski wrote:
Hello,

PROBLEM: transfer speed is ONLY HALF if queue is defined in pf.conf
although queue is 950Mbit (1000Mbit-5%)
pf disabled: 768 Mbits/sec
pf enabled, queue 950Mbit: 337 Mbits/sec

ANALYSIS:

- OpenBSD 4.8 default intallation.
- Test made between OpenBSD 4.8 and Debian Linux.
(between two Debian systems speed is more than 900Mbit/s)

*********************************************************
LAN interface: Intel PRO/1000 PT Desktop Adapter (PCIe, model:
EXPI9300PTBLK)
DMESG: em0 at pci1 dev 0 function 0 "Intel PRO/1000 PT (82572EI)" rev
0x06: apic 1 int 16 (irq 5), address 00:1b:21:05:1f:39
*********************************************************
Default settings of TCP window size:
net.inet.tcp.recvspace=16384
net.inet.tcp.sendspace=16384
*********************************************************

1a) pf disabled

r...@router-test (/root)# iperf -i 1 -t 3 -c 10.0.0.6
------------------------------------------------------------
Client connecting to 10.0.0.6, TCP port 5001
TCP window size: 16.0 KByte (default)
------------------------------------------------------------
[  3] local 10.0.0.8 port 27600 connected with 10.0.0.6 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0- 1.0 sec  54.7 MBytes    459 Mbits/sec
[ ID] Interval       Transfer     Bandwidth
[  3]  1.0- 2.0 sec  54.7 MBytes    458 Mbits/sec
[ ID] Interval       Transfer     Bandwidth
[  3]  2.0- 3.0 sec  54.7 MBytes    459 Mbits/sec

1b) pf enabled, no queue

r...@router-test (/root)# iperf -i 1 -t 3 -c 10.0.0.6
------------------------------------------------------------
Client connecting to 10.0.0.6, TCP port 5001
TCP window size: 16.0 KByte (default)
------------------------------------------------------------
[  3] local 10.0.0.8 port 46912 connected with 10.0.0.6 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0- 1.0 sec  53.9 MBytes    452 Mbits/sec
[ ID] Interval       Transfer     Bandwidth
[  3]  1.0- 2.0 sec  52.6 MBytes    441 Mbits/sec
[ ID] Interval       Transfer     Bandwidth
[  3]  2.0- 3.0 sec  54.1 MBytes    454 Mbits/sec

1c) pf enabled, added queue to default pf.conf:

altq on em0 cbq bandwidth 1Gb queue { q_lan }
queue q_lan bandwidth 950Mb cbq (default)

r...@router-test (/root)# iperf -i 1 -t 3 -c 10.0.0.6
------------------------------------------------------------
Client connecting to 10.0.0.6, TCP port 5001
TCP window size: 16.0 KByte (default)
------------------------------------------------------------
[  3] local 10.0.0.8 port 38266 connected with 10.0.0.6 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0- 1.0 sec  33.9 MBytes    284 Mbits/sec
[ ID] Interval       Transfer     Bandwidth
[  3]  1.0- 2.0 sec  35.0 MBytes    294 Mbits/sec
[ ID] Interval       Transfer     Bandwidth
[  3]  2.0- 3.0 sec  35.8 MBytes    300 Mbits/sec


*********************************************************
TCP window size changed to 131072.
net.inet.tcp.recvspace: 16384 ->  131072
net.inet.tcp.sendspace: 16384 ->  131072
*********************************************************

1a) pf disabled

r...@router-test (/root)# iperf -i 1 -t 3 -c 10.0.0.6
------------------------------------------------------------
Client connecting to 10.0.0.6, TCP port 5001
TCP window size:   128 KByte (default)
------------------------------------------------------------
[  3] local 10.0.0.8 port 32680 connected with 10.0.0.6 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0- 1.0 sec  91.5 MBytes    768 Mbits/sec
[ ID] Interval       Transfer     Bandwidth
[  3]  1.0- 2.0 sec  92.1 MBytes    773 Mbits/sec
[ ID] Interval       Transfer     Bandwidth
[  3]  2.0- 3.0 sec  91.2 MBytes    765 Mbits/sec

1b) pf enabled, no queue

r...@router-test (/root)# iperf -i 1 -t 3 -c 10.0.0.6
------------------------------------------------------------
Client connecting to 10.0.0.6, TCP port 5001
TCP window size:   128 KByte (default)
------------------------------------------------------------
[  3] local 10.0.0.8 port 41092 connected with 10.0.0.6 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0- 1.0 sec  80.5 MBytes    675 Mbits/sec
[ ID] Interval       Transfer     Bandwidth
[  3]  1.0- 2.0 sec  80.1 MBytes    672 Mbits/sec
[ ID] Interval       Transfer     Bandwidth
[  3]  2.0- 3.0 sec  80.2 MBytes    673 Mbits/sec

1c) pf enabled, added queue to default pf.conf:

altq on em0 cbq bandwidth 1Gb queue { q_lan }
queue q_lan bandwidth 950Mb cbq (default)

r...@router-test (/root)# iperf -i 1 -t 3 -c 10.0.0.6
------------------------------------------------------------
Client connecting to 10.0.0.6, TCP port 5001
TCP window size:   128 KByte (default)
------------------------------------------------------------
[  3] local 10.0.0.8 port 12499 connected with 10.0.0.6 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0- 1.0 sec  40.1 MBytes    337 Mbits/sec
[ ID] Interval       Transfer     Bandwidth
[  3]  1.0- 2.0 sec  40.1 MBytes    336 Mbits/sec
[ ID] Interval       Transfer     Bandwidth
[  3]  2.0- 3.0 sec  40.0 MBytes    335 Mbits/sec

*********************************************************

any ideas, suggestions about this situation?

The default length for a queue is 50 packets - this only allows you to queue
around 75,000 bytes and the burstiness of TCP slow-start is likely to well
exceed this in your configuration (due to the BDP). I'd suggest increasing
the queue length - also run 'pfctl -vvs queue' or 'systat queue' and see
what's happening with regards to packets drops.

ok, a set qlimit to 200 and then 500, no difference

queue root_em0 on em0 bandwidth 1Gb priority 0 qlimit 500 cbq( wrr root ) {q_lan} [ pkts: 858820 bytes: 1300055838 dropped pkts: 0 bytes: 0 ]
  [ qlength:   0/500  borrows:      0  suspends:      0 ]
  [ measured: 29222.9 packets/s, 353.90Mb/s ]
queue  q_lan on em0 bandwidth 950Mb qlimit 500 cbq( borrow default )
[ pkts: 858820 bytes: 1300055838 dropped pkts: 0 bytes: 0 ]
  [ qlength:   0/500  borrows:      0  suspends:      0 ]
  [ measured: 29222.9 packets/s, 353.90Mb/s ]


best regards,
RLW

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