performance in adhoc mode
Johann Hugo
jhugo at meraka.csir.co.za
Tue Mar 6 11:09:15 UTC 2012
On Wednesday 29 February 2012 19:48:53 you wrote:
> Ok, long_retry means that the hardware had to try more times to get
> the frame out.
>
> Either it's picking too high a rate, or the ACKs can't be heard.
Should be ok, they are one meter apart.
>
> I wonder what changes in the MAC and driver when we flip on adhoc
> mode. I know it changes how the beacon queue is handled, I didn't
> think anything else changed..
>
> Can you try forcing a lower rate on both ends (ifconfig wlanX
> ucastrate Y) and do your tests?
Are the parameters that one get with (ifconfig -m wlanX) still valid ?
See attached for tests.
B.t.w. I get better performance with our old FreeBSD-7.2 distro in adhoc mode
than with our new FreeBSD-9.0 distro on the same hardware.
FreeBSD-7.2
NodeA: iperf = 25.1 Mbits/sec
NodeB: iperf = 25.2 Mbits/sec
FreeBSD-9.0
NodeA: iperf = 20.5 Mbits/sec
NodeB: iperf =20.8 Mbits/sec
>
> Please file a PR with this. :)
Will do so.
Regards
Johann
>
> Thanks!
>
>
> Adrian
>
> On 29 February 2012 01:51, Johann Hugo <jhugo at meraka.csir.co.za> wrote:
> > On Tuesday 28 February 2012 17:50:39 Adrian Chadd wrote:
> >> I've not looked into adhoc _at all_.
> >
> > please_do
> >
> >> I'd start by looking at the behaviour of the rate control code - do
> >>
> >> 'sysctl dev.ath.X sample_stats=1' after you've done some traffic and
> >>
> >> check dmesg.
> >>
> >>
> >>
> >> Just ensure that the same rates are being used and the error rate is
> >> low.
> >
> > The rates differ a bit and also some of the dev.ath.0 sysctl's.
> > dev.ath.0.stats.ast_tx_longretry is more than double in adhoc mode.
> >
> >
> >
> > Johann
-------------- next part --------------
ifconfig wlan0 ucastrate 54Mbps
NodeA:
iperf = 21.3 Mbits/sec
mesh-2893:~ # sysctl dev.ath.0.sample_stats=1
dev.ath.0.sample_stats: 0
[00:80:48:4f:28:93] refcnt 4 static_rix 0 ratemask 0x0
[ 250] cur rix 0 (6 Mb ) since switch: packets 0 ticks 0
[ 250] last sample 0 cur sample 0 packets sent 0
[ 250] packets since sample 0 sample tt 0
[1600] cur rix 0 (6 Mb ) since switch: packets 0 ticks 0
[1600] last sample 0 cur sample 0 packets sent 0
[1600] packets since sample 0 sample tt 0
[00:80:48:4f:28:70] refcnt 3 static_rix 7 ratemask 0xff
[ 250] cur rix 0 (6 Mb ) since switch: packets 0 ticks 0
[ 250] last sample 0 cur sample -1 packets sent 13008
[ 250] packets since sample 0 sample tt 0
[1600] cur rix 0 (6 Mb ) since switch: packets 0 ticks 0
[1600] last sample 0 cur sample -1 packets sent 0
[1600] packets since sample 0 sample tt 0
[54 Mb : 250] 13007:13006 ( 99%) T 14574 F 0 avg 463 last 1491
[54 Mb :1600] 1:0 ( 0%) T 12 F 1 avg 644 last 1712
mesh-2893:~ # sysctl dev.ath.0.stats.ast_tx_longretry
dev.ath.0.stats.ast_tx_longretry: 1567
NodeB:
iperf = 21.7 Mbits/sec
mesh-2870:~ # sysctl dev.ath.0.sample_stats=1
dev.ath.0.sample_stats: 0
[00:80:48:4f:28:70] refcnt 4 static_rix 0 ratemask 0x0
[ 250] cur rix 0 (6 Mb ) since switch: packets 0 ticks 0
[ 250] last sample 0 cur sample 0 packets sent 0
[ 250] packets since sample 0 sample tt 0
[1600] cur rix 0 (6 Mb ) since switch: packets 0 ticks 0
[1600] last sample 0 cur sample 0 packets sent 0
[1600] packets since sample 0 sample tt 0
[00:80:48:4f:28:93] refcnt 3 static_rix 7 ratemask 0xff
[ 250] cur rix 0 (6 Mb ) since switch: packets 0 ticks 0
[ 250] last sample 0 cur sample -1 packets sent 13
[ 250] packets since sample 0 sample tt 0
[1600] cur rix 0 (6 Mb ) since switch: packets 0 ticks 0
[1600] last sample 0 cur sample -1 packets sent 18967
[1600] packets since sample 0 sample tt 0
[54 Mb : 250] 13:13 (100%) T 13 F 0 avg 444 last 2039
[54 Mb :1600] 18831:18830 ( 99%) T 20559 F 0 avg 681 last 2040
mesh-2870:~ # sysctl dev.ath.0.stats.ast_tx_longretry
dev.ath.0.stats.ast_tx_longretry: 1728
---------------------------------------------------------------------------------------
ifconfig wlan0 ucastrate 48Mbps
NodeA:
iperf = 21.1 Mbits/sec
dev.ath.0.sample_stats: 0
[00:80:48:4f:28:93] refcnt 4 static_rix 0 ratemask 0x0
[ 250] cur rix 0 (6 Mb ) since switch: packets 0 ticks 0
[ 250] last sample 0 cur sample 0 packets sent 0
[ 250] packets since sample 0 sample tt 0
[1600] cur rix 0 (6 Mb ) since switch: packets 0 ticks 0
[1600] last sample 0 cur sample 0 packets sent 0
[1600] packets since sample 0 sample tt 0
[00:80:48:4f:28:70] refcnt 3 static_rix 6 ratemask 0xff
[ 250] cur rix 0 (6 Mb ) since switch: packets 0 ticks 0
[ 250] last sample 0 cur sample -1 packets sent 12522
[ 250] packets since sample 0 sample tt 0
[1600] cur rix 0 (6 Mb ) since switch: packets 0 ticks 0
[1600] last sample 0 cur sample -1 packets sent 0
[1600] packets since sample 0 sample tt 0
[48 Mb : 250] 12522:12522 (100%) T 13980 F 0 avg 695 last 16081
mesh-2893:~ # sysctl dev.ath.0.stats.ast_tx_longretry
dev.ath.0.stats.ast_tx_longretry: 1476
NodeB:
iperf = 21.4 Mbits/sec
dev.ath.0.sample_stats: 0
[00:80:48:4f:28:93] refcnt 4 static_rix 0 ratemask 0x0
[ 250] cur rix 0 (6 Mb ) since switch: packets 0 ticks 0
[ 250] last sample 0 cur sample 0 packets sent 0
[ 250] packets since sample 0 sample tt 0
[1600] cur rix 0 (6 Mb ) since switch: packets 0 ticks 0
[1600] last sample 0 cur sample 0 packets sent 0
[1600] packets since sample 0 sample tt 0
[00:80:48:4f:28:70] refcnt 3 static_rix 6 ratemask 0xff
[ 250] cur rix 0 (6 Mb ) since switch: packets 0 ticks 0
[ 250] last sample 0 cur sample -1 packets sent 12522
[ 250] packets since sample 0 sample tt 0
[1600] cur rix 0 (6 Mb ) since switch: packets 0 ticks 0
[1600] last sample 0 cur sample -1 packets sent 0
[1600] packets since sample 0 sample tt 0
[48 Mb : 250] 12522:12522 (100%) T 13980 F 0 avg 695 last 16081
mesh-2870:~ # sysctl dev.ath.0.stats.ast_tx_longretry
dev.ath.0.stats.ast_tx_longretry: 1516
---------------------------------------------------------------------------------------
ifconfig wlan0 ucastrate 36Mbps
NodeA:
iperf = 18.0 Mbits/sec
^Cmesh-2893:~ # sysctl dev.ath.0.sample_stats=1
dev.ath.0.sample_stats: 0
[00:80:48:4f:28:93] refcnt 4 static_rix 0 ratemask 0x0
[ 250] cur rix 0 (6 Mb ) since switch: packets 0 ticks 0
[ 250] last sample 0 cur sample 0 packets sent 0
[ 250] packets since sample 0 sample tt 0
[1600] cur rix 0 (6 Mb ) since switch: packets 0 ticks 0
[1600] last sample 0 cur sample 0 packets sent 0
[1600] packets since sample 0 sample tt 0
[00:80:48:4f:28:70] refcnt 3 static_rix 5 ratemask 0xff
[ 250] cur rix 0 (6 Mb ) since switch: packets 0 ticks 0
[ 250] last sample 0 cur sample -1 packets sent 10664
[ 250] packets since sample 0 sample tt 0
[1600] cur rix 0 (6 Mb ) since switch: packets 0 ticks 0
[1600] last sample 0 cur sample -1 packets sent 0
[1600] packets since sample 0 sample tt 0
[36 Mb : 250] 10664:10664 (100%) T 11876 F 0 avg 548 last 1505
mesh-2893:~ # sysctl dev.ath.0.stats.ast_tx_longretry
dev.ath.0.stats.ast_tx_longretry: 1240
NodeB:
iperf = 18.3 Mbits/sec
mesh-2870:~ # sysctl dev.ath.0.sample_stats=1
dev.ath.0.sample_stats: 0
[00:80:48:4f:28:70] refcnt 4 static_rix 0 ratemask 0x0
[ 250] cur rix 0 (6 Mb ) since switch: packets 0 ticks 0
[ 250] last sample 0 cur sample 0 packets sent 0
[ 250] packets since sample 0 sample tt 0
[1600] cur rix 0 (6 Mb ) since switch: packets 0 ticks 0
[1600] last sample 0 cur sample 0 packets sent 0
[1600] packets since sample 0 sample tt 0
[00:80:48:4f:28:93] refcnt 3 static_rix 5 ratemask 0xff
[ 250] cur rix 0 (6 Mb ) since switch: packets 0 ticks 0
[ 250] last sample 0 cur sample -1 packets sent 5
[ 250] packets since sample 0 sample tt 0
[1600] cur rix 0 (6 Mb ) since switch: packets 0 ticks 0
[1600] last sample 0 cur sample -1 packets sent 15841
[1600] packets since sample 0 sample tt 0
[36 Mb : 250] 5:5 (100%) T 5 F 0 avg 464 last 1679
[36 Mb :1600] 15841:15841 (100%) T 17056 F 0 avg 878 last 1682
mesh-2870:~ # sysctl dev.ath.0.stats.ast_tx_longretry
dev.ath.0.stats.ast_tx_longretry: 1223
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