TxOP 0 has a special meaning in the standard. For HT/VHT it means the it is actually limited to 5484us (mixed-mode) or 10000us (greenfield). I suspect the BK/BE latency difference has to do with the fact that there's bulk traffic going on BE queues (this isn't reflected explicitly in the plots). The `bursts` flent test includes short bursts of traffic on tid0 (BE) which is shared with ICMP and BE UDP_RR (seen as green and blue lines on the plot). Due to (intended) limited outflow (6mbps) BE queues build up and don't drain for the duration of the entire test creating more opportunities for aggregating BE traffic while other queues are near-empty and very short (time wise as well). If you consider Wi-Fi is half-duplex and latency in the entire stack (for processing ICMP and UDP_RR) is greater than 11e contention window timings you can get your BE flow responses with extra delay (since other queues might have responses ready quicker). I've modified traffic-gen and re-run tests with bursts on all tested tids/ACs (tid0, tid1, tid5). I'm attaching the results. With bursts on all tids you can clearly see BK has much higher latency than BE. (Note, I've changed my AP to QCA988X with oldie firmware 10.1.467 for this test; it doesn't have the weird hiccups I was seeing on QCA99X0 and newer QCA988X firmware reports bogus expected throughput which is most likely a result of my sloppy proof-of-concept change in ath10k). Michał On 16 March 2016 at 20:48, Jasmine Strong <jas@xxxxxxxx> wrote: > BK usually has 0 txop, so it doesn't do aggregation. > > On Wed, Mar 16, 2016 at 11:55 AM, Bob Copeland <me@xxxxxxxxxxxxxxx> wrote: >> >> On Wed, Mar 16, 2016 at 11:36:31AM -0700, Dave Taht wrote: >> > That is the sanest 802.11e queue behavior I have ever seen! (at both >> > 6 and 300mbit! in the ath10k patched mac test) >> >> Out of curiosity, why does BE have larger latency than BK in that chart? >> I'd have expected the opposite. >> >> -- >> Bob Copeland %% http://bobcopeland.com/ >> >> _______________________________________________ >> ath10k mailing list >> ath10k@xxxxxxxxxxxxxxxxxxx >> http://lists.infradead.org/mailman/listinfo/ath10k > >
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