* [ath9k-devel] How to lock AMPDU length at a specific value? @ 2014-01-22 5:19 Shinnazar 2014-01-22 7:08 ` Kamran Nishat 0 siblings, 1 reply; 13+ messages in thread From: Shinnazar @ 2014-01-22 5:19 UTC (permalink / raw) To: ath9k-devel An HTML attachment was scrubbed... URL: http://lists.ath9k.org/pipermail/ath9k-devel/attachments/20140122/1a0cbe6d/attachment.htm ^ permalink raw reply [flat|nested] 13+ messages in thread
* [ath9k-devel] How to lock AMPDU length at a specific value? 2014-01-22 5:19 [ath9k-devel] How to lock AMPDU length at a specific value? Shinnazar @ 2014-01-22 7:08 ` Kamran Nishat 2014-01-22 15:51 ` Ali Abedi 0 siblings, 1 reply; 13+ messages in thread From: Kamran Nishat @ 2014-01-22 7:08 UTC (permalink / raw) To: ath9k-devel Yeah, My initial premise was that u have saturated traffic from upper layers. But now I think u have some application level requirements (data rate is less than max PHY rate). In this case I would advise you to add wait in mac80211. Because as far as I know ath9k driven by its calls and calls by driver. Regards, kamran On Wed, Jan 22, 2014 at 10:19 AM, Shinnazar <seytnazarovsho@ynu.ac.kr>wrote: > Hi Ali, > > If I were you, I would try to make the Software queue always full of > frames and then specify ampdu lenfth in ath_tx_form_aggr(). > > BR, > Shinnazar > > --- Original Message --- > *From : *Ali Abedi< a2abedi@uwaterloo.ca > > *To : *ath9k-devel at venema.h4ckr.net > *CC : * > *Sent : *2014-01-22 06:40:18 > *Subject : *Re: [ath9k-devel] Fwd: How to lock AMPDU length at a specific > value? > > > _______________________________________________ > ath9k-devel mailing listath9k-devel at lists.ath9k.orghttps://lists.ath9k.org/mailman/listinfo/ath9k-devel > > Using a constant rate does not help (I am already doing this). When I set > the limit to 20 for example, I get any number between > 1 to 20 for the number of aggregated frames. This is probably because when > we want to start the transmission > we don't always have 20 frames to aggregate so the card aggregates all it > already has > in the queue ready for transmission. So how can we wait to have 20 frames > ready for transmission so that > all aggregate frames carry exactly 20 frames (constant rate)? > > Thank you, > Ali > > > On 21/01/2014 15:59, Kamran Nishat wrote: > > > > > > do it at a fix rate (1st check if duration of packet is less tahn 4ms for > ur MCS) and with nearly zero noise losses. > > Kamran > > > On Wed, Jan 22, 2014 at 1:54 AM, Ali Abedi <a2abedi@uwaterloo.ca> wrote: > >> These mostly determine the MAX AMPDU length. I also want to determine >> the minimum length, so >> that I can set min=max and lock the AMPDU length. >> >> Thank you, >> Ali >> >> On 21/01/2014 15:07, Kamran Nishat wrote: >> >> As far as i know AMPDU length is determined by 3 constraints. Firs maximum >> AMPDU length. second blockAck window (if there were losses then this will >> play a role). Third is Max air time of the AMPDU which is 4ms for some >> domain constraints. this comes into play MCS is low and packet duration >> gets more than 4ms. See following function in xmit.c for details >> >> ath_tx_form_aggr <http://lxr.free-electrons.com/ident?i=ath_tx_form_aggr> >> >> >> >> On Tue, Jan 21, 2014 at 11:49 PM, Ali Abedi <a2abedi@uwaterloo.ca> wrote: >> >>> Hello, >>> >>> I have seen questions regarding the length of an AMPDU and how to change >>> the maximum AMPDU length. >>> However, I require to lock the AMPDU length at a specific value. >>> Changing the max length does not guarantee >>> that all AMPDUs have a fixed length, it can be anything between 1 to max >>> based on the rate of arrival of new frames. >>> Is there a mechanism to force the card to wait to have enough frames so >>> that all AMPDUs have a fixed length that we specify? In other words, I >>> need all AMPDUs to aggregate X full length frames. >>> >>> Thank you, >>> Ali >>> >>> _______________________________________________ >>> ath9k-devel mailing list >>> ath9k-devel at lists.ath9k.org >>> https://lists.ath9k.org/mailman/listinfo/ath9k-devel >>> >> >> >> > > > > _______________________________________________ > ath9k-devel mailing listath9k-devel at lists.ath9k.orghttps://lists.ath9k.org/mailman/listinfo/ath9k-devel > > > > > > > > > _______________________________________________ > ath9k-devel mailing list > ath9k-devel at lists.ath9k.org > https://lists.ath9k.org/mailman/listinfo/ath9k-devel > > -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.ath9k.org/pipermail/ath9k-devel/attachments/20140122/e8417ceb/attachment.htm ^ permalink raw reply [flat|nested] 13+ messages in thread
* [ath9k-devel] How to lock AMPDU length at a specific value? 2014-01-22 7:08 ` Kamran Nishat @ 2014-01-22 15:51 ` Ali Abedi 2014-01-22 16:02 ` Kamran Nishat 0 siblings, 1 reply; 13+ messages in thread From: Ali Abedi @ 2014-01-22 15:51 UTC (permalink / raw) To: ath9k-devel Thanks for all the replies. Sorry for not mentioning that I actually saturate the link. I use iperf and I set the application data rate to something way more that the mac throughput. The strange thing is that not all A-MPDUs are at the maximum size. Here is some results I got from the driver for different max A-MPDU sizes (High app data rate). left column is #frames and the column is #bad-frames Mac data rate = 65 Mbps fixed. App data rate = 100 Mbps I directly print these stats from xmit.c in ath_tx_complete_agg(), after the call to function ath_tx_count_frames(). I print nframes and nbad variables. max A-mpdu size = 10 * 1550 B 10 0 10 0 10 0 10 0 10 0 10 0 10 0 10 0 10 0 Everything is fine all A-MPDUs have 10 frames ----------------------- max A-mpdu size = 20 * 1550 B 20 0 20 0 20 0 9 0 20 0 20 0 1 0 20 0 20 0 8 0 20 0 Sometimes a-mpdus with fewer frames than 20 ----------------------- Max A-mpdu size = 32 * 1550 B 8 0 32 0 2 0 32 32 3 0 32 0 1 0 32 0 4 4 1 0 32 32 It happens even more frequently. Is there a solution to this problem? Thank you, Ali On 14-01-22 02:08 AM, Kamran Nishat wrote: > Yeah, > My initial premise was that u have saturated traffic from upper > layers. But now I think u have some application level requirements > (data rate is less than max PHY rate). > In this case I would advise you to add wait in mac80211. Because as > far as I know ath9k driven by its calls and calls by driver. > > Regards, > kamran > > > On Wed, Jan 22, 2014 at 10:19 AM, Shinnazar <seytnazarovsho@ynu.ac.kr > <mailto:seytnazarovsho@ynu.ac.kr>> wrote: > > Hi Ali, > > If I were you, I would try to make the Software queue always full > of frames and then specify ampdu lenfth in ath_tx_form_aggr(). > > BR, > Shinnazar > > --- Original Message --- > *From : *Ali Abedi< a2abedi@uwaterloo.ca > <mailto:a2abedi@uwaterloo.ca> > > *To : *ath9k-devel at venema.h4ckr.net > <mailto:ath9k-devel@venema.h4ckr.net> > *CC : * > *Sent : *2014-01-22 06:40:18 > *Subject : *Re: [ath9k-devel] Fwd: How to lock AMPDU length at > a specific value? > > > _______________________________________________ > ath9k-devel mailing list > ath9k-devel at lists.ath9k.org <mailto:ath9k-devel@lists.ath9k.org> > https://lists.ath9k.org/mailman/listinfo/ath9k-devel > > Using a constant rate does not help (I am already doing this). > When I set the limit to 20 for example, I get any number between > 1 to 20 for the number of aggregated frames. This is probably > because when we want to start the transmission > we don't always have 20 frames to aggregate so the card > aggregates all it already has > in the queue ready for transmission. So how can we wait to > have 20 frames ready for transmission so that > all aggregate frames carry exactly 20 frames (constant rate)? > > Thank you, > Ali > > > On 21/01/2014 15:59, Kamran Nishat wrote: >> >> >> >> >> do it at a fix rate (1st check if duration of packet is less >> tahn 4ms for ur MCS) and with nearly zero noise losses. >> >> Kamran >> >> >> On Wed, Jan 22, 2014 at 1:54 AM, Ali Abedi >> <a2abedi at uwaterloo.ca <mailto:a2abedi@uwaterloo.ca>> wrote: >> >> These mostly determine the MAX AMPDU length. I also want >> to determine the minimum length, so >> that I can set min=max and lock the AMPDU length. >> >> Thank you, >> Ali >> >> On 21/01/2014 15:07, Kamran Nishat wrote: >>> As far as i know AMPDU length is determined by 3 >>> constraints. Firs maximum AMPDU length. second blockAck >>> window (if there were losses then this will play a >>> role). Third is Max air time of the AMPDU which is 4ms >>> for some domain constraints. this comes into play MCS is >>> low and packet duration gets more than 4ms. See >>> following function in xmit.c for details >>> ath_tx_form_aggr <http://lxr.free-electrons.com/ident?i=ath_tx_form_aggr> >>> >>> >>> On Tue, Jan 21, 2014 at 11:49 PM, Ali Abedi >>> <a2abedi at uwaterloo.ca <mailto:a2abedi@uwaterloo.ca>> wrote: >>> >>> Hello, >>> >>> I have seen questions regarding the length of an >>> AMPDU and how to change >>> the maximum AMPDU length. >>> However, I require to lock the AMPDU length at a >>> specific value. >>> Changing the max length does not guarantee >>> that all AMPDUs have a fixed length, it can be >>> anything between 1 to max >>> based on the rate of arrival of new frames. >>> Is there a mechanism to force the card to wait to >>> have enough frames so >>> that all AMPDUs have a fixed length that we specify? >>> In other words, I >>> need all AMPDUs to aggregate X full length frames. >>> >>> Thank you, >>> Ali >>> >>> _______________________________________________ >>> ath9k-devel mailing list >>> ath9k-devel at lists.ath9k.org >>> <mailto:ath9k-devel@lists.ath9k.org> >>> https://lists.ath9k.org/mailman/listinfo/ath9k-devel >>> >>> >> >> >> >> >> >> _______________________________________________ >> ath9k-devel mailing list >> ath9k-devel at lists.ath9k.org <mailto:ath9k-devel@lists.ath9k.org> >> https://lists.ath9k.org/mailman/listinfo/ath9k-devel > > > > > > > > _______________________________________________ > ath9k-devel mailing list > ath9k-devel at lists.ath9k.org <mailto:ath9k-devel@lists.ath9k.org> > https://lists.ath9k.org/mailman/listinfo/ath9k-devel > > -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.ath9k.org/pipermail/ath9k-devel/attachments/20140122/e9b7b211/attachment.htm ^ permalink raw reply [flat|nested] 13+ messages in thread
* [ath9k-devel] How to lock AMPDU length at a specific value? 2014-01-22 15:51 ` Ali Abedi @ 2014-01-22 16:02 ` Kamran Nishat 2014-01-22 16:35 ` Ruwaifa Anwar 2014-01-26 16:25 ` Ali Abedi 0 siblings, 2 replies; 13+ messages in thread From: Kamran Nishat @ 2014-01-22 16:02 UTC (permalink / raw) To: ath9k-devel Check if they are probe or not. Probes can have different size. other thing but prints in ath_tx_form_aggr() as i mentioned before check which condition is stopping the loop. One more thing there are some losses. In case of losses BlockAck window BAW will stop aggregate from growing. kamran On Wed, Jan 22, 2014 at 8:51 PM, Ali Abedi <a2abedi@uwaterloo.ca> wrote: > Thanks for all the replies. > Sorry for not mentioning that I actually saturate the link. I use iperf > and I set the application data rate > to something way more that the mac throughput. The strange thing is that > not all A-MPDUs are at the maximum size. > > Here is some results I got from the driver for different max A-MPDU sizes > (High app data rate). > > left column is #frames and the column is #bad-frames > Mac data rate = 65 Mbps fixed. > App data rate = 100 Mbps > > I directly print these stats from xmit.c in ath_tx_complete_agg(), after > the call to function ath_tx_count_frames(). > I print nframes and nbad variables. > > max A-mpdu size = 10 * 1550 B > 10 0 > 10 0 > 10 0 > 10 0 > 10 0 > 10 0 > 10 0 > 10 0 > 10 0 > > Everything is fine all A-MPDUs have 10 frames > ----------------------- > max A-mpdu size = 20 * 1550 B > 20 0 > 20 0 > 20 0 > 9 0 > 20 0 > 20 0 > 1 0 > 20 0 > 20 0 > 8 0 > 20 0 > > Sometimes a-mpdus with fewer frames than 20 > ----------------------- > Max A-mpdu size = 32 * 1550 B > 8 0 > 32 0 > 2 0 > 32 32 > 3 0 > 32 0 > 1 0 > 32 0 > 4 4 > 1 0 > 32 32 > > It happens even more frequently. > > Is there a solution to this problem? > > Thank you, > Ali > > > > On 14-01-22 02:08 AM, Kamran Nishat wrote: > > Yeah, > My initial premise was that u have saturated traffic from upper layers. > But now I think u have some application level requirements (data rate is > less than max PHY rate). > In this case I would advise you to add wait in mac80211. Because as far as > I know ath9k driven by its calls and calls by driver. > > Regards, > kamran > > > On Wed, Jan 22, 2014 at 10:19 AM, Shinnazar <seytnazarovsho@ynu.ac.kr>wrote: > >> Hi Ali, >> >> If I were you, I would try to make the Software queue always full of >> frames and then specify ampdu lenfth in ath_tx_form_aggr(). >> >> BR, >> Shinnazar >> >> --- Original Message --- >> *From : *Ali Abedi< a2abedi@uwaterloo.ca > >> *To : *ath9k-devel at venema.h4ckr.net >> *CC : * >> *Sent : *2014-01-22 06:40:18 >> *Subject : *Re: [ath9k-devel] Fwd: How to lock AMPDU length at a >> specific value? >> >> >> _______________________________________________ >> ath9k-devel mailing listath9k-devel at lists.ath9k.orghttps://lists.ath9k.org/mailman/listinfo/ath9k-devel >> >> Using a constant rate does not help (I am already doing this). When I set >> the limit to 20 for example, I get any number between >> 1 to 20 for the number of aggregated frames. This is probably because >> when we want to start the transmission >> we don't always have 20 frames to aggregate so the card aggregates all it >> already has >> in the queue ready for transmission. So how can we wait to have 20 frames >> ready for transmission so that >> all aggregate frames carry exactly 20 frames (constant rate)? >> >> Thank you, >> Ali >> >> >> On 21/01/2014 15:59, Kamran Nishat wrote: >> >> >> >> >> >> do it at a fix rate (1st check if duration of packet is less tahn 4ms >> for ur MCS) and with nearly zero noise losses. >> >> Kamran >> >> >> On Wed, Jan 22, 2014 at 1:54 AM, Ali Abedi <a2abedi@uwaterloo.ca> wrote: >> >>> These mostly determine the MAX AMPDU length. I also want to determine >>> the minimum length, so >>> that I can set min=max and lock the AMPDU length. >>> >>> Thank you, >>> Ali >>> >>> On 21/01/2014 15:07, Kamran Nishat wrote: >>> >>> As far as i know AMPDU length is determined by 3 constraints. Firs maximum >>> AMPDU length. second blockAck window (if there were losses then this will >>> play a role). Third is Max air time of the AMPDU which is 4ms for some >>> domain constraints. this comes into play MCS is low and packet duration >>> gets more than 4ms. See following function in xmit.c for details >>> >>> ath_tx_form_aggr <http://lxr.free-electrons.com/ident?i=ath_tx_form_aggr> >>> >>> >>> >>> On Tue, Jan 21, 2014 at 11:49 PM, Ali Abedi <a2abedi@uwaterloo.ca>wrote: >>> >>>> Hello, >>>> >>>> I have seen questions regarding the length of an AMPDU and how to change >>>> the maximum AMPDU length. >>>> However, I require to lock the AMPDU length at a specific value. >>>> Changing the max length does not guarantee >>>> that all AMPDUs have a fixed length, it can be anything between 1 to max >>>> based on the rate of arrival of new frames. >>>> Is there a mechanism to force the card to wait to have enough frames so >>>> that all AMPDUs have a fixed length that we specify? In other words, I >>>> need all AMPDUs to aggregate X full length frames. >>>> >>>> Thank you, >>>> Ali >>>> >>>> _______________________________________________ >>>> ath9k-devel mailing list >>>> ath9k-devel at lists.ath9k.org >>>> https://lists.ath9k.org/mailman/listinfo/ath9k-devel >>>> >>> >>> >>> >> >> >> >> _______________________________________________ >> ath9k-devel mailing listath9k-devel at lists.ath9k.orghttps://lists.ath9k.org/mailman/listinfo/ath9k-devel >> >> >> >> >> >> >> >> >> _______________________________________________ >> ath9k-devel mailing list >> ath9k-devel at lists.ath9k.org >> https://lists.ath9k.org/mailman/listinfo/ath9k-devel >> >> > > -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.ath9k.org/pipermail/ath9k-devel/attachments/20140122/8bbca2af/attachment-0001.htm ^ permalink raw reply [flat|nested] 13+ messages in thread
* [ath9k-devel] How to lock AMPDU length at a specific value? 2014-01-22 16:02 ` Kamran Nishat @ 2014-01-22 16:35 ` Ruwaifa Anwar 2014-01-26 16:25 ` Ali Abedi 1 sibling, 0 replies; 13+ messages in thread From: Ruwaifa Anwar @ 2014-01-22 16:35 UTC (permalink / raw) To: ath9k-devel yup, block-ack window limit appears to be the main culprit behind your reduced ampdu lengths. Check ath_tx_form_aggr, there is an if-condition specifically checking whether your are exceeding block-ack window or not. If your sending rate is quite high then increased lossess might trigger this condition quite frequently ^ permalink raw reply [flat|nested] 13+ messages in thread
* [ath9k-devel] How to lock AMPDU length at a specific value? 2014-01-22 16:02 ` Kamran Nishat 2014-01-22 16:35 ` Ruwaifa Anwar @ 2014-01-26 16:25 ` Ali Abedi 2014-01-26 18:55 ` Kamran Nishat 1 sibling, 1 reply; 13+ messages in thread From: Ali Abedi @ 2014-01-26 16:25 UTC (permalink / raw) To: ath9k-devel Thank you. I checked ath_tx_form_aggr() and the condition that checks: do not step over block-ack window causes the A-MPDU length limitation. So is there anything to do to force max A-MPDU length? Does setting retry to 1 solves this problem? My understanding is that if retry is 1 then we move the BA window anyway (regardless of frame error) by 32 each time. Is this right? Thanks, Ali On 22/01/2014 11:02, Kamran Nishat wrote: > Check if they are probe or not. Probes can have different size. other > thing but prints in ath_tx_form_aggr() as i mentioned before check > which condition is stopping the loop. > One more thing there are some losses. In case of losses BlockAck > window BAW will stop aggregate from growing. > kamran > > > On Wed, Jan 22, 2014 at 8:51 PM, Ali Abedi <a2abedi@uwaterloo.ca > <mailto:a2abedi@uwaterloo.ca>> wrote: > > Thanks for all the replies. > Sorry for not mentioning that I actually saturate the link. I use > iperf and I set the application data rate > to something way more that the mac throughput. The strange thing > is that not all A-MPDUs are at the maximum size. > > Here is some results I got from the driver for different max > A-MPDU sizes (High app data rate). > > left column is #frames and the column is #bad-frames > Mac data rate = 65 Mbps fixed. > App data rate = 100 Mbps > > I directly print these stats from xmit.c in ath_tx_complete_agg(), > after the call to function ath_tx_count_frames(). > I print nframes and nbad variables. > > max A-mpdu size = 10 * 1550 B > 10 0 > 10 0 > 10 0 > 10 0 > 10 0 > 10 0 > 10 0 > 10 0 > 10 0 > > Everything is fine all A-MPDUs have 10 frames > ----------------------- > max A-mpdu size = 20 * 1550 B > 20 0 > 20 0 > 20 0 > 9 0 > 20 0 > 20 0 > 1 0 > 20 0 > 20 0 > 8 0 > 20 0 > > Sometimes a-mpdus with fewer frames than 20 > ----------------------- > Max A-mpdu size = 32 * 1550 B > 8 0 > 32 0 > 2 0 > 32 32 > 3 0 > 32 0 > 1 0 > 32 0 > 4 4 > 1 0 > 32 32 > > It happens even more frequently. > > Is there a solution to this problem? > > Thank you, > Ali > > > > On 14-01-22 02:08 AM, Kamran Nishat wrote: >> Yeah, >> My initial premise was that u have saturated traffic from upper >> layers. But now I think u have some application level >> requirements (data rate is less than max PHY rate). >> In this case I would advise you to add wait in mac80211. Because >> as far as I know ath9k driven by its calls and calls by driver. >> >> Regards, >> kamran >> >> >> On Wed, Jan 22, 2014 at 10:19 AM, Shinnazar >> <seytnazarovsho at ynu.ac.kr <mailto:seytnazarovsho@ynu.ac.kr>> wrote: >> >> Hi Ali, >> >> If I were you, I would try to make the Software queue always >> full of frames and then specify ampdu lenfth in >> ath_tx_form_aggr(). >> >> BR, >> Shinnazar >> >> --- Original Message --- >> *From : *Ali Abedi< a2abedi@uwaterloo.ca >> <mailto:a2abedi@uwaterloo.ca> > >> *To : *ath9k-devel at venema.h4ckr.net >> <mailto:ath9k-devel@venema.h4ckr.net> >> *CC : * >> *Sent : *2014-01-22 06:40:18 >> *Subject : *Re: [ath9k-devel] Fwd: How to lock AMPDU >> length at a specific value? >> >> >> _______________________________________________ >> ath9k-devel mailing list >> ath9k-devel at lists.ath9k.org <mailto:ath9k-devel@lists.ath9k.org> >> https://lists.ath9k.org/mailman/listinfo/ath9k-devel >> >> Using a constant rate does not help (I am already doing >> this). When I set the limit to 20 for example, I get any >> number between >> 1 to 20 for the number of aggregated frames. This is >> probably because when we want to start the transmission >> we don't always have 20 frames to aggregate so the card >> aggregates all it already has >> in the queue ready for transmission. So how can we wait >> to have 20 frames ready for transmission so that >> all aggregate frames carry exactly 20 frames (constant rate)? >> >> Thank you, >> Ali >> >> >> On 21/01/2014 15:59, Kamran Nishat wrote: >>> >>> >>> >>> >>> do it at a fix rate (1st check if duration of packet is >>> less tahn 4ms for ur MCS) and with nearly zero noise losses. >>> >>> Kamran >>> >>> >>> On Wed, Jan 22, 2014 at 1:54 AM, Ali Abedi >>> <a2abedi at uwaterloo.ca <mailto:a2abedi@uwaterloo.ca>> wrote: >>> >>> These mostly determine the MAX AMPDU length. I also >>> want to determine the minimum length, so >>> that I can set min=max and lock the AMPDU length. >>> >>> Thank you, >>> Ali >>> >>> On 21/01/2014 15:07, Kamran Nishat wrote: >>>> As far as i know AMPDU length is determined by 3 >>>> constraints. Firs maximum AMPDU length. second >>>> blockAck window (if there were losses then this >>>> will play a role). Third is Max air time of the >>>> AMPDU which is 4ms for some domain constraints. >>>> this comes into play MCS is low and packet duration >>>> gets more than 4ms. See following function in >>>> xmit.c for details >>>> ath_tx_form_aggr <http://lxr.free-electrons.com/ident?i=ath_tx_form_aggr> >>>> >>>> >>>> On Tue, Jan 21, 2014 at 11:49 PM, Ali Abedi >>>> <a2abedi@uwaterloo.ca >>>> <mailto:a2abedi@uwaterloo.ca>> wrote: >>>> >>>> Hello, >>>> >>>> I have seen questions regarding the length of >>>> an AMPDU and how to change >>>> the maximum AMPDU length. >>>> However, I require to lock the AMPDU length at >>>> a specific value. >>>> Changing the max length does not guarantee >>>> that all AMPDUs have a fixed length, it can be >>>> anything between 1 to max >>>> based on the rate of arrival of new frames. >>>> Is there a mechanism to force the card to wait >>>> to have enough frames so >>>> that all AMPDUs have a fixed length that we >>>> specify? In other words, I >>>> need all AMPDUs to aggregate X full length frames. >>>> >>>> Thank you, >>>> Ali >>>> >>>> _______________________________________________ >>>> ath9k-devel mailing list >>>> ath9k-devel at lists.ath9k.org >>>> <mailto:ath9k-devel@lists.ath9k.org> >>>> https://lists.ath9k.org/mailman/listinfo/ath9k-devel >>>> >>>> >>> >>> >>> >>> >>> >>> _______________________________________________ >>> ath9k-devel mailing list >>> ath9k-devel at lists.ath9k.org <mailto:ath9k-devel@lists.ath9k.org> >>> https://lists.ath9k.org/mailman/listinfo/ath9k-devel >> >> >> >> >> >> >> >> _______________________________________________ >> ath9k-devel mailing list >> ath9k-devel at lists.ath9k.org <mailto:ath9k-devel@lists.ath9k.org> >> https://lists.ath9k.org/mailman/listinfo/ath9k-devel >> >> > > -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.ath9k.org/pipermail/ath9k-devel/attachments/20140126/879ea50c/attachment-0001.htm ^ permalink raw reply [flat|nested] 13+ messages in thread
* [ath9k-devel] How to lock AMPDU length at a specific value? 2014-01-26 16:25 ` Ali Abedi @ 2014-01-26 18:55 ` Kamran Nishat 0 siblings, 0 replies; 13+ messages in thread From: Kamran Nishat @ 2014-01-26 18:55 UTC (permalink / raw) To: ath9k-devel Thank you. I checked ath_tx_form_aggr() and the condition that checks: do not step over block-ack window causes the A-MPDU length limitation. So is there anything to do to force max A-MPDU length? *YES! we told you earlier if link is lossy then this limit will not let AMPDU to increase.* Does setting retry to 1 solves this problem? My understanding is that if retry is 1 then we move the BA window anyway (regardless of frame error) by 32 each time. Is this right? *As far as we know HW does the AMPDU retries. while SW retries are done if **ATH_MAX_SW_RETRIES is not achieved( ath_tx_complete_aggr in xmit.c**) * On Sun, Jan 26, 2014 at 9:25 PM, Ali Abedi <a2abedi@uwaterloo.ca> wrote: > Thank you. I checked ath_tx_form_aggr() and the condition that checks: > do not step over block-ack window > causes the A-MPDU length limitation. So is there anything to do to force > max A-MPDU length? > Does setting retry to 1 solves this problem? My understanding is that if > retry is 1 then we move the BA window > anyway (regardless of frame error) by 32 each time. Is this right? > > Thanks, > Ali > > > On 22/01/2014 11:02, Kamran Nishat wrote: > > Check if they are probe or not. Probes can have different size. other > thing but prints in ath_tx_form_aggr() as i mentioned before check which > condition is stopping the loop. > One more thing there are some losses. In case of losses BlockAck window > BAW will stop aggregate from growing. > kamran > > > On Wed, Jan 22, 2014 at 8:51 PM, Ali Abedi <a2abedi@uwaterloo.ca> wrote: > >> Thanks for all the replies. >> Sorry for not mentioning that I actually saturate the link. I use iperf >> and I set the application data rate >> to something way more that the mac throughput. The strange thing is that >> not all A-MPDUs are at the maximum size. >> >> Here is some results I got from the driver for different max A-MPDU sizes >> (High app data rate). >> >> left column is #frames and the column is #bad-frames >> Mac data rate = 65 Mbps fixed. >> App data rate = 100 Mbps >> >> I directly print these stats from xmit.c in ath_tx_complete_agg(), after >> the call to function ath_tx_count_frames(). >> I print nframes and nbad variables. >> >> max A-mpdu size = 10 * 1550 B >> 10 0 >> 10 0 >> 10 0 >> 10 0 >> 10 0 >> 10 0 >> 10 0 >> 10 0 >> 10 0 >> >> Everything is fine all A-MPDUs have 10 frames >> ----------------------- >> max A-mpdu size = 20 * 1550 B >> 20 0 >> 20 0 >> 20 0 >> 9 0 >> 20 0 >> 20 0 >> 1 0 >> 20 0 >> 20 0 >> 8 0 >> 20 0 >> >> Sometimes a-mpdus with fewer frames than 20 >> ----------------------- >> Max A-mpdu size = 32 * 1550 B >> 8 0 >> 32 0 >> 2 0 >> 32 32 >> 3 0 >> 32 0 >> 1 0 >> 32 0 >> 4 4 >> 1 0 >> 32 32 >> >> It happens even more frequently. >> >> Is there a solution to this problem? >> >> Thank you, >> Ali >> >> >> >> On 14-01-22 02:08 AM, Kamran Nishat wrote: >> >> Yeah, >> My initial premise was that u have saturated traffic from upper layers. >> But now I think u have some application level requirements (data rate is >> less than max PHY rate). >> In this case I would advise you to add wait in mac80211. Because as far >> as I know ath9k driven by its calls and calls by driver. >> >> Regards, >> kamran >> >> >> On Wed, Jan 22, 2014 at 10:19 AM, Shinnazar <seytnazarovsho@ynu.ac.kr>wrote: >> >>> Hi Ali, >>> >>> If I were you, I would try to make the Software queue always full of >>> frames and then specify ampdu lenfth in ath_tx_form_aggr(). >>> >>> BR, >>> Shinnazar >>> >>> --- Original Message --- >>> *From : *Ali Abedi< a2abedi@uwaterloo.ca > >>> *To : *ath9k-devel at venema.h4ckr.net >>> *CC : * >>> *Sent : *2014-01-22 06:40:18 >>> *Subject : *Re: [ath9k-devel] Fwd: How to lock AMPDU length at a >>> specific value? >>> >>> >>> _______________________________________________ >>> ath9k-devel mailing listath9k-devel at lists.ath9k.orghttps://lists.ath9k.org/mailman/listinfo/ath9k-devel >>> >>> Using a constant rate does not help (I am already doing this). When I >>> set the limit to 20 for example, I get any number between >>> 1 to 20 for the number of aggregated frames. This is probably because >>> when we want to start the transmission >>> we don't always have 20 frames to aggregate so the card aggregates all >>> it already has >>> in the queue ready for transmission. So how can we wait to have 20 >>> frames ready for transmission so that >>> all aggregate frames carry exactly 20 frames (constant rate)? >>> >>> Thank you, >>> Ali >>> >>> >>> On 21/01/2014 15:59, Kamran Nishat wrote: >>> >>> >>> >>> >>> >>> do it at a fix rate (1st check if duration of packet is less tahn 4ms >>> for ur MCS) and with nearly zero noise losses. >>> >>> Kamran >>> >>> >>> On Wed, Jan 22, 2014 at 1:54 AM, Ali Abedi <a2abedi@uwaterloo.ca>wrote: >>> >>>> These mostly determine the MAX AMPDU length. I also want to determine >>>> the minimum length, so >>>> that I can set min=max and lock the AMPDU length. >>>> >>>> Thank you, >>>> Ali >>>> >>>> On 21/01/2014 15:07, Kamran Nishat wrote: >>>> >>>> As far as i know AMPDU length is determined by 3 constraints. Firs maximum >>>> AMPDU length. second blockAck window (if there were losses then this will >>>> play a role). Third is Max air time of the AMPDU which is 4ms for some >>>> domain constraints. this comes into play MCS is low and packet duration >>>> gets more than 4ms. See following function in xmit.c for details >>>> >>>> ath_tx_form_aggr <http://lxr.free-electrons.com/ident?i=ath_tx_form_aggr> >>>> >>>> >>>> >>>> On Tue, Jan 21, 2014 at 11:49 PM, Ali Abedi <a2abedi@uwaterloo.ca>wrote: >>>> >>>>> Hello, >>>>> >>>>> I have seen questions regarding the length of an AMPDU and how to >>>>> change >>>>> the maximum AMPDU length. >>>>> However, I require to lock the AMPDU length at a specific value. >>>>> Changing the max length does not guarantee >>>>> that all AMPDUs have a fixed length, it can be anything between 1 to >>>>> max >>>>> based on the rate of arrival of new frames. >>>>> Is there a mechanism to force the card to wait to have enough frames so >>>>> that all AMPDUs have a fixed length that we specify? In other words, I >>>>> need all AMPDUs to aggregate X full length frames. >>>>> >>>>> Thank you, >>>>> Ali >>>>> >>>>> _______________________________________________ >>>>> ath9k-devel mailing list >>>>> ath9k-devel at lists.ath9k.org >>>>> https://lists.ath9k.org/mailman/listinfo/ath9k-devel >>>>> >>>> >>>> >>>> >>> >>> >>> >>> _______________________________________________ >>> ath9k-devel mailing listath9k-devel at lists.ath9k.orghttps://lists.ath9k.org/mailman/listinfo/ath9k-devel >>> >>> >>> >>> >>> >>> >>> >>> >>> _______________________________________________ >>> ath9k-devel mailing list >>> ath9k-devel at lists.ath9k.org >>> https://lists.ath9k.org/mailman/listinfo/ath9k-devel >>> >>> >> >> > > -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.ath9k.org/pipermail/ath9k-devel/attachments/20140126/94f3d57f/attachment-0001.htm ^ permalink raw reply [flat|nested] 13+ messages in thread
* [ath9k-devel] How to lock AMPDU length at a specific value? @ 2014-01-23 5:19 Shinnazar 0 siblings, 0 replies; 13+ messages in thread From: Shinnazar @ 2014-01-23 5:19 UTC (permalink / raw) To: ath9k-devel An HTML attachment was scrubbed... URL: http://lists.ath9k.org/pipermail/ath9k-devel/attachments/20140123/3ce3c180/attachment-0001.htm ^ permalink raw reply [flat|nested] 13+ messages in thread
* [ath9k-devel] How to lock AMPDU length at a specific value? @ 2014-01-23 5:06 Shinnazar 2014-01-26 15:12 ` Ali Abedi 0 siblings, 1 reply; 13+ messages in thread From: Shinnazar @ 2014-01-23 5:06 UTC (permalink / raw) To: ath9k-devel An HTML attachment was scrubbed... URL: http://lists.ath9k.org/pipermail/ath9k-devel/attachments/20140123/261381a5/attachment.htm ^ permalink raw reply [flat|nested] 13+ messages in thread
* [ath9k-devel] How to lock AMPDU length at a specific value? 2014-01-23 5:06 Shinnazar @ 2014-01-26 15:12 ` Ali Abedi 0 siblings, 0 replies; 13+ messages in thread From: Ali Abedi @ 2014-01-26 15:12 UTC (permalink / raw) To: ath9k-devel Hi, Thank you for your reply. This fixed half of the problem. If the link quality is good all A-MPDUs are at the maximum length, however if the link quality is not good (high error) many A-MPDUs are smaller than the maximum A-MPDU length. As mentioned before it has something to do with the block ack window. If I set retry limit to 1 shouldn't this fix the problem? This way we don't care what happens to the frame, as we wont retransmit anyways. I have modified the minstrel_ht to lock the retry at 1 (i.e., ar[0].count = 1, and ar[1].idx=-1 ar[1].count=0). However the printk in tx_status sometimes shows attempts higher than 1. Why is that? Thank you, Ali On 23/01/2014 00:06, Shinnazar wrote: > Hi Ali, > > Iperf has some strange behavior like this. Now you try to run 2 or 3 > parallel iperf threads, for example smth like this: iperf -c "Receiver > address" -u -t 10 -i 1 -b 50m -p 2. Hope this will help. > > BE, > Shinnazar > > --- Original Message --- > *From : *Ali Abedi< a2abedi@uwaterloo.ca > > *To : *ath9k-devel< ath9k-devel@venema.h4ckr.net > > *CC : *Kamran Nishat< kamran.nishat@gmail.com >,Shinnazar< > seytnazarovsho at ynu.ac.kr > > *Sent : *2014-01-23 00:51:23 > *Subject : *Re: [ath9k-devel] How to lock AMPDU length at a > specific value? > > Thanks for all the replies. > Sorry for not mentioning that I actually saturate the link. I use > iperf and I set the application data rate > to something way more that the mac throughput. The strange thing > is that not all A-MPDUs are at the maximum size. > > Here is some results I got from the driver for different max > A-MPDU sizes (High app data rate). > > left column is #frames and the column is #bad-frames > Mac data rate = 65 Mbps fixed. > App data rate = 100 Mbps > > I directly print these stats from xmit.c in ath_tx_complete_agg(), > after the call to function ath_tx_count_frames(). > I print nframes and nbad variables. > > max A-mpdu size = 10 * 1550 B > 10 0 > 10 0 > 10 0 > 10 0 > 10 0 > 10 0 > 10 0 > 10 0 > 10 0 > > Everything is fine all A-MPDUs have 10 frames > ----------------------- > max A-mpdu size = 20 * 1550 B > 20 0 > 20 0 > 20 0 > 9 0 > 20 0 > 20 0 > 1 0 > 20 0 > 20 0 > 8 0 > 20 0 > > Sometimes a-mpdus with fewer frames than 20 > ----------------------- > Max A-mpdu size = 32 * 1550 B > 8 0 > 32 0 > 2 0 > 32 32 > 3 0 > 32 0 > 1 0 > 32 0 > 4 4 > 1 0 > 32 32 > > It happens even more frequently. > > Is there a solution to this problem? > > Thank you, > Ali > > > On 14-01-22 02:08 AM, Kamran Nishat wrote: >> Yeah, >> My initial premise was that u have saturated traffic from upper >> layers. But now I think u have some application level >> requirements (data rate is less than max PHY rate). >> In this case I would advise you to add wait in mac80211. Because >> as far as I know ath9k driven by its calls and calls by driver. >> >> Regards, >> kamran >> >> >> On Wed, Jan 22, 2014 at 10:19 AM, Shinnazar >> <seytnazarovsho at ynu.ac.kr <mailto:seytnazarovsho@ynu.ac.kr>> wrote: >> >> Hi Ali, >> >> If I were you, I would try to make the Software queue always >> full of frames and then specify ampdu lenfth in >> ath_tx_form_aggr(). >> >> BR, >> Shinnazar >> >> --- Original Message --- >> *From : *Ali Abedi< a2abedi@uwaterloo.ca >> <mailto:a2abedi@uwaterloo.ca> > >> *To : *ath9k-devel at venema.h4ckr.net >> <mailto:ath9k-devel@venema.h4ckr.net> >> *CC : * >> *Sent : *2014-01-22 06:40:18 >> *Subject : *Re: [ath9k-devel] Fwd: How to lock AMPDU >> length at a specific value? >> >> >> _______________________________________________ >> ath9k-devel mailing list >> ath9k-devel at lists.ath9k.org <mailto:ath9k-devel@lists.ath9k.org> >> https://lists.ath9k.org/mailman/listinfo/ath9k-devel >> >> Using a constant rate does not help (I am already doing >> this). When I set the limit to 20 for example, I get any >> number between >> 1 to 20 for the number of aggregated frames. This is >> probably because when we want to start the transmission >> we don't always have 20 frames to aggregate so the card >> aggregates all it already has >> in the queue ready for transmission. So how can we wait >> to have 20 frames ready for transmission so that >> all aggregate frames carry exactly 20 frames (constant rate)? >> >> Thank you, >> Ali >> >> >> On 21/01/2014 15:59, Kamran Nishat wrote: >>> >>> >>> >>> >>> do it at a fix rate (1st check if duration of packet is >>> less tahn 4ms for ur MCS) and with nearly zero noise losses. >>> >>> Kamran >>> >>> >>> On Wed, Jan 22, 2014 at 1:54 AM, Ali Abedi >>> <a2abedi at uwaterloo.ca <mailto:a2abedi@uwaterloo.ca>> wrote: >>> >>> These mostly determine the MAX AMPDU length. I also >>> want to determine the minimum length, so >>> that I can set min=max and lock the AMPDU length. >>> >>> Thank you, >>> Ali >>> >>> On 21/01/2014 15:07, Kamran Nishat wrote: >>>> As far as i know AMPDU length is determined by 3 >>>> constraints. Firs maximum AMPDU length. second >>>> blockAck window (if there were losses then this >>>> will play a role). Third is Max air time of the >>>> AMPDU which is 4ms for some domain constraints. >>>> this comes into play MCS is low and packet duration >>>> gets more than 4ms. See following function in >>>> xmit.c for details >>>> ath_tx_form_aggr <http://lxr.free-electrons.com/ident?i=ath_tx_form_aggr> >>>> >>>> >>>> On Tue, Jan 21, 2014 at 11:49 PM, Ali Abedi >>>> <a2abedi@uwaterloo.ca >>>> <mailto:a2abedi@uwaterloo.ca>> wrote: >>>> >>>> Hello, >>>> >>>> I have seen questions regarding the length of >>>> an AMPDU and how to change >>>> the maximum AMPDU length. >>>> However, I require to lock the AMPDU length at >>>> a specific value. >>>> Changing the max length does not guarantee >>>> that all AMPDUs have a fixed length, it can be >>>> anything between 1 to max >>>> based on the rate of arrival of new frames. >>>> Is there a mechanism to force the card to wait >>>> to have enough frames so >>>> that all AMPDUs have a fixed length that we >>>> specify? In other words, I >>>> need all AMPDUs to aggregate X full length frames. >>>> >>>> Thank you, >>>> Ali >>>> >>>> _______________________________________________ >>>> ath9k-devel mailing list >>>> ath9k-devel at lists.ath9k.org >>>> <mailto:ath9k-devel@lists.ath9k.org> >>>> https://lists.ath9k.org/mailman/listinfo/ath9k-devel >>>> >>>> >>> >>> >>> >>> >>> >>> _______________________________________________ >>> ath9k-devel mailing list >>> ath9k-devel at lists.ath9k.org <mailto:ath9k-devel@lists.ath9k.org> >>> https://lists.ath9k.org/mailman/listinfo/ath9k-devel >> >> >> >> >> >> >> >> _______________________________________________ >> ath9k-devel mailing list >> ath9k-devel at lists.ath9k.org <mailto:ath9k-devel@lists.ath9k.org> >> https://lists.ath9k.org/mailman/listinfo/ath9k-devel >> >> > > > > > > -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.ath9k.org/pipermail/ath9k-devel/attachments/20140126/08a61217/attachment-0001.htm ^ permalink raw reply [flat|nested] 13+ messages in thread
* [ath9k-devel] How to lock AMPDU length at a specific value? @ 2014-01-21 18:49 Ali Abedi 2014-01-21 20:07 ` Kamran Nishat 0 siblings, 1 reply; 13+ messages in thread From: Ali Abedi @ 2014-01-21 18:49 UTC (permalink / raw) To: ath9k-devel Hello, I have seen questions regarding the length of an AMPDU and how to change the maximum AMPDU length. However, I require to lock the AMPDU length at a specific value. Changing the max length does not guarantee that all AMPDUs have a fixed length, it can be anything between 1 to max based on the rate of arrival of new frames. Is there a mechanism to force the card to wait to have enough frames so that all AMPDUs have a fixed length that we specify? In other words, I need all AMPDUs to aggregate X full length frames. Thank you, Ali ^ permalink raw reply [flat|nested] 13+ messages in thread
* [ath9k-devel] How to lock AMPDU length at a specific value? 2014-01-21 18:49 Ali Abedi @ 2014-01-21 20:07 ` Kamran Nishat 2014-01-21 20:54 ` Ali Abedi 0 siblings, 1 reply; 13+ messages in thread From: Kamran Nishat @ 2014-01-21 20:07 UTC (permalink / raw) To: ath9k-devel As far as i know AMPDU length is determined by 3 constraints. Firs maximum AMPDU length. second blockAck window (if there were losses then this will play a role). Third is Max air time of the AMPDU which is 4ms for some domain constraints. this comes into play MCS is low and packet duration gets more than 4ms. See following function in xmit.c for details ath_tx_form_aggr <http://lxr.free-electrons.com/ident?i=ath_tx_form_aggr> On Tue, Jan 21, 2014 at 11:49 PM, Ali Abedi <a2abedi@uwaterloo.ca> wrote: > Hello, > > I have seen questions regarding the length of an AMPDU and how to change > the maximum AMPDU length. > However, I require to lock the AMPDU length at a specific value. > Changing the max length does not guarantee > that all AMPDUs have a fixed length, it can be anything between 1 to max > based on the rate of arrival of new frames. > Is there a mechanism to force the card to wait to have enough frames so > that all AMPDUs have a fixed length that we specify? In other words, I > need all AMPDUs to aggregate X full length frames. > > Thank you, > Ali > > _______________________________________________ > ath9k-devel mailing list > ath9k-devel at lists.ath9k.org > https://lists.ath9k.org/mailman/listinfo/ath9k-devel > -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.ath9k.org/pipermail/ath9k-devel/attachments/20140122/78970f47/attachment.htm ^ permalink raw reply [flat|nested] 13+ messages in thread
* [ath9k-devel] How to lock AMPDU length at a specific value? 2014-01-21 20:07 ` Kamran Nishat @ 2014-01-21 20:54 ` Ali Abedi 0 siblings, 0 replies; 13+ messages in thread From: Ali Abedi @ 2014-01-21 20:54 UTC (permalink / raw) To: ath9k-devel These mostly determine the MAX AMPDU length. I also want to determine the minimum length, so that I can set min=max and lock the AMPDU length. Thank you, Ali On 21/01/2014 15:07, Kamran Nishat wrote: > As far as i know AMPDU length is determined by 3 constraints. Firs > maximum AMPDU length. second blockAck window (if there were losses > then this will play a role). Third is Max air time of the AMPDU which > is 4ms for some domain constraints. this comes into play MCS is low > and packet duration gets more than 4ms. See following function in > xmit.c for details > ath_tx_form_aggr <http://lxr.free-electrons.com/ident?i=ath_tx_form_aggr> > > > On Tue, Jan 21, 2014 at 11:49 PM, Ali Abedi <a2abedi@uwaterloo.ca > <mailto:a2abedi@uwaterloo.ca>> wrote: > > Hello, > > I have seen questions regarding the length of an AMPDU and how to > change > the maximum AMPDU length. > However, I require to lock the AMPDU length at a specific value. > Changing the max length does not guarantee > that all AMPDUs have a fixed length, it can be anything between 1 > to max > based on the rate of arrival of new frames. > Is there a mechanism to force the card to wait to have enough > frames so > that all AMPDUs have a fixed length that we specify? In other words, I > need all AMPDUs to aggregate X full length frames. > > Thank you, > Ali > > _______________________________________________ > ath9k-devel mailing list > ath9k-devel at lists.ath9k.org <mailto:ath9k-devel@lists.ath9k.org> > https://lists.ath9k.org/mailman/listinfo/ath9k-devel > > -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.ath9k.org/pipermail/ath9k-devel/attachments/20140121/e4153d00/attachment.htm ^ permalink raw reply [flat|nested] 13+ messages in thread
end of thread, other threads:[~2014-01-26 18:55 UTC | newest] Thread overview: 13+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2014-01-22 5:19 [ath9k-devel] How to lock AMPDU length at a specific value? Shinnazar 2014-01-22 7:08 ` Kamran Nishat 2014-01-22 15:51 ` Ali Abedi 2014-01-22 16:02 ` Kamran Nishat 2014-01-22 16:35 ` Ruwaifa Anwar 2014-01-26 16:25 ` Ali Abedi 2014-01-26 18:55 ` Kamran Nishat -- strict thread matches above, loose matches on Subject: below -- 2014-01-23 5:19 Shinnazar 2014-01-23 5:06 Shinnazar 2014-01-26 15:12 ` Ali Abedi 2014-01-21 18:49 Ali Abedi 2014-01-21 20:07 ` Kamran Nishat 2014-01-21 20:54 ` Ali Abedi
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