Re: [ath5k-devel] Performance regression between Madwifi/net80211 and ath5k/mac80211
On Wed, Oct 19, 2011 at 8:55 AM, Pavel Roskin pro...@gnu.org wrote: On Wed, 19 Oct 2011 19:33:53 +0800 Adrian Chadd adr...@freebsd.org wrote: .. does madwifi have that net80211 aggressive mode by default, where it overrides the best-effort WME queue parameters to allow for bursting? I tried madwifi-0.9.4 snapshot on a CM9 card, and I got: # iwpriv ath0 get_abolt ath0 get_abolt:218 218 is 0xda, which means that the following capabilities are enabled: IEEE80211_ABOLT_TURBO_PRIME IEEE80211_ABOLT_FAST_FRAME IEEE80211_ABOLT_BURST IEEE80211_ABOLT_XR IEEE80211_ABOLT_AR And those are not enabled: IEEE80211_ABOLT_TURBO_G IEEE80211_ABOLT_COMPRESSION IEEE80211_ABOLT_WME_ELE I would just unset all capabilities and retry. I see exactly that difference in FreeBSD (33mbit vs 22mbit) when I disable that aggressive mode code. Bursting will get you to ~28 and FF's are likely the reset (no dynamic turbo on freebsd). It would be nice to have control in linux to explicitly turn on/off bursting but the usual way people do it is to negotiate wmm and force the txop limit. BTW whenever you see a performance difference the first thing to look at is packets/sec. I've not found any linux tools that give me this a la athstats/wlanstats on freebsd. -Sam ___ ath5k-devel mailing list ath5k-devel@lists.ath5k.org https://lists.ath5k.org/mailman/listinfo/ath5k-devel
Re: [ath5k-devel] Performance regression between Madwifi/net80211 and ath5k/mac80211
Bob, real world work interfered back in June but now I have a few more data points. I made a cross test with ath5k on Fedora 2.6.40 (e.g. 3.0) and Madwifi-0.9.4 on 2.6.23. The interesting observation is, that the ath5k bottleneck seems to be on the transmission end, e.g if the iperf client is attached to ath5k, the performance is consistently lower. Here is a table: ath5k-ath5k = iperf server attached to ath5k, iperf client attached to ath5k madwifi-ath5k = iperf server attached to madwifi, iperf client attached to ath5k ath5k-madwifi = iperf server attached to ath5k, iperf client attached to madwifi madwifi-madwifi = iperf server attached to madwifi, iperf client attached to madwifi Note that on iperf the server is the traffic sink (and the measurement point) and the client is the traffic source. Measured traffic was UDP as generated by iperf -c ip of server -u -b 54M -t 15 The test setup was as followed: * 59db attenuation between the two boxes (calibrated HF cable) * Frequency 5200MHz (eg. 802.11a channel 40) * txpower 10dBm on both sides * ANI disabled on Madwifi *SLOW* *SLOW* *FAST* *FAST* ath5k-ath5k madwifi-ath5k ath5k-madwifi madwifi-madwifi 2755368027553680 7426440 33998160 28082880 28135800 24866520 33851160 28212240 28212240 32281200 33615960 28323960 28112280 33033840 34027560 28300440 28259280 32363520 34303920 28088760 28276920 34739040 34021680 28112280 28212240 34874280 34415640 28247520 28088760 34298040 33886440 28247520 28235760 34004040 34292160 28176960 28141680 34944840 34409760 2793 28224000 35015400 34174560 28206360 28159320 35085960 34403880 28135800 28082880 33574800 33951120 28135800 28041720 34986000 34045200 28147560 27965280 35133000 34174560 I will run with tcpdump on a monitoring interface for the combination ath5k sender and madwifi sender shortly. Where should I capture the trace? -- Regards Joerg - Ursprüngliche Message - Von: Bob Copeland m...@bobcopeland.com An: Joerg Pommnitz pommn...@yahoo.com Cc: linux-wirel...@vger.kernel.org; ath5k-devel@lists.ath5k.org Gesendet: 13:02 Donnerstag, 30.Juni 2011 Betreff: Re: [ath5k-devel] Performance regression between Madwifi/net80211 and ath5k/mac80211 On Wed, Jun 22, 2011 at 11:07 AM, Joerg Pommnitz pommn...@yahoo.com wrote: I guess you'll need more help from the HW people here. Bob, Bruno, Felix, Luis, Nick: Do you read? I guess I would be interested to know if there are any obvious differences in the streams. E.g. taking a monitor mode capture near the receiver should show whether the received power is similar, whether the # of retransmissions is significantly higher in ath5k vs madwifi, whether packets are sent at the same bitrates, if there are any pauses where ath5k doesn't seem to be doing anything, etc. Would it be possible to do a few captures with your setup? -- Bob Copeland %% www.bobcopeland.com ___ ath5k-devel mailing list ath5k-devel@lists.ath5k.org https://lists.ath5k.org/mailman/listinfo/ath5k-devel
Re: [ath5k-devel] Performance regression between Madwifi/net80211 and ath5k/mac80211
.. does madwifi have that net80211 aggressive mode by default, where it overrides the best-effort WME queue parameters to allow for bursting? I see exactly that difference in FreeBSD (33mbit vs 22mbit) when I disable that aggressive mode code. Thanks, Adrian ___ ath5k-devel mailing list ath5k-devel@lists.ath5k.org https://lists.ath5k.org/mailman/listinfo/ath5k-devel
Re: [ath5k-devel] Performance regression between Madwifi/net80211 and ath5k/mac80211
On Wed, 19 Oct 2011 19:33:53 +0800 Adrian Chadd adr...@freebsd.org wrote: .. does madwifi have that net80211 aggressive mode by default, where it overrides the best-effort WME queue parameters to allow for bursting? I tried madwifi-0.9.4 snapshot on a CM9 card, and I got: # iwpriv ath0 get_abolt ath0 get_abolt:218 218 is 0xda, which means that the following capabilities are enabled: IEEE80211_ABOLT_TURBO_PRIME IEEE80211_ABOLT_FAST_FRAME IEEE80211_ABOLT_BURST IEEE80211_ABOLT_XR IEEE80211_ABOLT_AR And those are not enabled: IEEE80211_ABOLT_TURBO_G IEEE80211_ABOLT_COMPRESSION IEEE80211_ABOLT_WME_ELE I would just unset all capabilities and retry. I see exactly that difference in FreeBSD (33mbit vs 22mbit) when I disable that aggressive mode code. -- Regards, Pavel Roskin ___ ath5k-devel mailing list ath5k-devel@lists.ath5k.org https://lists.ath5k.org/mailman/listinfo/ath5k-devel
Re: [ath5k-devel] Performance regression between Madwifi/net80211 and ath5k/mac80211
Felix, thanks for taking an interest in this. To answer your questions: Originally I ran the stock Fedora 15 wireless modules from kernel 2.6.38.8-32.fc15.i686. Today I reran the test with the wireless modules from compat-wireless-3.0-rc4-1. Unfortunately there doesn't seem to be any difference. Attached are the summary lines from a 100secon TCP iperf run: ath5k from kernel 2.6.38.8-32.fc15: [ 4] 0.0-100.7 sec 265 MBytes 22.1 Mbits/sec ath5k from compat-wireless-3.0-rc4-1: [ 4] 0.0-100.9 sec 268 MBytes 22.2 Mbits/sec madwifi-0.9.4-r4144-20110602: [ 4] 0.0-100.4 sec 306 MBytes 25.6 Mbits/sec There is obviously little performance change from 2.6.38 to the current 3.0 version of ath5k. And there is a significant performance loss relative to Madwifi. The iperf tests were run in 802.11a (channel 40) in IBSS mode. Similar performance differences were previously observed in AP mode as well. -- Thanks and kind regards Joerg - Original Mail Von: Felix Fietkau n...@openwrt.org An: Joerg Pommnitz pommn...@yahoo.com CC: linux-wirel...@vger.kernel.org; ath5k-devel@lists.ath5k.org Gesendet: Sonntag, den 26. Juni 2011, 16:45:29 Uhr Betreff: Re: [ath5k-devel] Performance regression between Madwifi/net80211 and ath5k/mac80211 On 2011-06-22 5:07 PM, Joerg Pommnitz wrote: I guess you'll need more help from the HW people here. Bob, Bruno, Felix, Luis, Nick: Do you read? What mac80211/ath5k version did you use? If you're using the in-kernel ath5k from 2.6.38, then I'd suggest testing with a recent compat-wireless version. I made some bug fixes and performance improvements in April - and I think those went into 2.6.39. - Felix ___ ath5k-devel mailing list ath5k-devel@lists.ath5k.org https://lists.ath5k.org/mailman/listinfo/ath5k-devel
Re: [ath5k-devel] Performance regression between Madwifi/net80211 and ath5k/mac80211
On 2011-06-22 5:07 PM, Joerg Pommnitz wrote: I guess you'll need more help from the HW people here. Bob, Bruno, Felix, Luis, Nick: Do you read? What mac80211/ath5k version did you use? If you're using the in-kernel ath5k from 2.6.38, then I'd suggest testing with a recent compat-wireless version. I made some bug fixes and performance improvements in April - and I think those went into 2.6.39. - Felix ___ ath5k-devel mailing list ath5k-devel@lists.ath5k.org https://lists.ath5k.org/mailman/listinfo/ath5k-devel
Re: [ath5k-devel] Performance regression between Madwifi/net80211 and ath5k/mac80211
On Wed, 2011-06-22 at 06:41 -0700, Joerg Pommnitz wrote: Adrian, thanks for taking an interest. Today I built the current Madwifi driver for Fedora Kernel 2.6.38.8-32.fc15.i686. The ath5k problem seems to be at the tx side. If I run the iperf server on the ath5k node and the iperf client at the madwifi node (identical hardware config), I consistently get a significant speedup compared to ath5k-ath5k. The only difference is, which module is blacklisted. I have experimented with the RTS and fragmentation threshold setting without success. Now I'm somewhat lost. The problem is either ath5k or mac80211. Do you see different CPU usage? Does it max out? If so can you profile it? johannes ___ ath5k-devel mailing list ath5k-devel@lists.ath5k.org https://lists.ath5k.org/mailman/listinfo/ath5k-devel
Re: [ath5k-devel] Performance regression between Madwifi/net80211 and ath5k/mac80211
I guess you'll need more help from the HW people here. Bob, Bruno, Felix, Luis, Nick: Do you read? -- Regards Joerg ___ ath5k-devel mailing list ath5k-devel@lists.ath5k.org https://lists.ath5k.org/mailman/listinfo/ath5k-devel
Re: [ath5k-devel] Performance regression between Madwifi/net80211 and ath5k/mac80211
On Wed, 22 Jun 2011 08:02:38 -0700 (PDT) Joerg Pommnitz pommn...@yahoo.com wrote: I guess you'll need more help from the HW people here. Unless the delay is somewhere in the generic mac80211 stack. The older Atheros hardware is unique, because it has not just two hardware drivers but also two 802.11 stacks. It would be nice if somebody could do a similar test with two different 802.11 stacks and drivers. Comparing the performance between libertas and libertas_tf might provide an interesting data point. I can confirm the performance loss. I tested three madwifi versions with open hal and the openwrt binary hal version. ath5k has worst performance. Simple ftp file transfer was used as a test. And I used AP - station case. ath5k as AP, ath9k as station. Results are: ~2.7 Mb/s for open hal madwifi 3 Mb/s for binary hal madwifi 2 Mb/s for ath5k If I have some time, I will try to investigate the problem. -- Best regards, Nikolay Ledovskikh. ___ ath5k-devel mailing list ath5k-devel@lists.ath5k.org https://lists.ath5k.org/mailman/listinfo/ath5k-devel
Re: [ath5k-devel] Performance regression between Madwifi/net80211 and ath5k/mac80211
2011/6/22 jpo pommn...@yahoo.com: Hello all, there seems to be a significant performance loss when moving from Madwifi to ath5k. For an embedded project we have been using Madwifi with Linux kernel 2.6.23. We have tested ath5k for some time and by now it seems to be stable enough for production use. Unfortunately it doesn't match Madwifi's performance. Running iperf (both, UDP and TCP) between two machines equipped with an AR5413 with the Fedora 15 kernel and the stock Fedora 15 wireless subsystem shows a performance loss of about 10% relative to 2.6.23 and Madwifi-0.9.4. The tests where done under close to ideal lab conditions (cards connected with an antenna cable) running an IBSS network on channel 40 (5200MHz). Can anybody confirm this observation? Is there an explanation? Are there some tuning knobs I could try to improve the performance with mac80211/ath5k? Is the problem outside the wireless subsystem (Maybe it's the TCP/IP stack or something Fedora specific)? Thanks in advance. Joerg I can confirm the performance loss. I tested three madwifi versions with open hal and the openwrt binary hal version. ath5k has worst performance. Simple ftp file transfer was used as a test. And I used AP - station case. ath5k as AP, ath9k as station. Results are: ~2.7 Mb/s for open hal madwifi 3 Mb/s for binary hal madwifi 2 Mb/s for ath5k If I have some time, I will help to investigate the problem. -- Best regards, Nikolay Ledovskikh. ___ ath5k-devel mailing list ath5k-devel@lists.ath5k.org https://lists.ath5k.org/mailman/listinfo/ath5k-devel
