Wen Gong <wgong@xxxxxxxxxxxxxxxx> writes: >> -----Original Message----- >> From: ath10k <ath10k-bounces@xxxxxxxxxxxxxxxxxxx> On Behalf Of Toke >> Høiland-Jørgensen >> Sent: Wednesday, August 8, 2018 6:44 PM >> To: Wen Gong <wgong@xxxxxxxxxxxxxx>; ath10k@xxxxxxxxxxxxxxxxxxx; >> johannes@xxxxxxxxxxxxxxxx >> Cc: linux-wireless@xxxxxxxxxxxxxxx >> Subject: Re: [PATCH v2 2/2] ath10k: Set sk_pacing_shift to 6 for 11AC WiFi >> chips >> >> Wen Gong <wgong@xxxxxxxxxxxxxx> writes: >> >> > Upstream kernel has an interface to help adjust sk_pacing_shift to >> > help improve TCP UL throughput. >> > The sk_pacing_shift is 8 in mac80211, this is based on test with 11N >> > WiFi chips with ath9k. For QCA6174/QCA9377 PCI 11AC chips, the 11AC >> > VHT80 TCP UL throughput testing result shows 6 is the optimal. >> > Overwrite the sk_pacing_shift to 6 in ath10k driver for QCA6174/9377 PCI. >> > >> > Tested with QCA6174 PCI with firmware >> > WLAN.RM.4.4.1-00109-QCARMSWPZ-1, but this will also affect QCA9377 >> PCI. >> > It's not a regression with new firmware releases. >> > >> > There have 2 test result of different settings: >> > >> > ARM CPU based device with QCA6174A PCI with different >> > sk_pacing_shift: >> > >> > sk_pacing_shift throughput(Mbps) CPU utilization >> > 6 500(-P5) ~75% idle, Focus on CPU1: ~14%idle >> > 7 454(-P5) ~80% idle, Focus on CPU1: ~4%idle >> > 8 288 ~90% idle, Focus on CPU1: ~35%idle >> > 9 ~200 ~92% idle, Focus on CPU1: ~50%idle >> > >> > 5G TCP UL VTH80 on X86 platform with QCA6174A PCI with >> > sk_packing_shift set to 6: >> > >> > tcp_limit_output_bytes throughput(Mbps) >> > default(262144)+1 Stream 336 >> > default(262144)+2 Streams 558 >> > default(262144)+3 Streams 584 >> > default(262144)+4 Streams 602 >> > default(262144)+5 Streams 598 >> > changed(2621440)+1 Stream 598 >> > changed(2621440)+2 Streams 601 >> >> You still haven't provided any latency numbers for these tests, which makes >> it impossible to verify that setting sk_pacing_shift to 6 is the right tradeoff. >> >> As I said before, from your numbers I suspect the right setting is actually 7, >> which would be 10-20ms less latency under load; way more important than >> ~50 Mbps... >> > Hi Toke, > Could you give the command line for the latency test? > https://flent.org/intro.html#quick-start > I used the command but test failed: > flent tcp_download -p 1 -l 60 -H 192.168.1.5 -t text-to-be-included-in-plot -o file1.png > error loading plotter: unable to find plot configuration "1" Try something like: flent -H 192.168.1.5 -t "sk_pacing_shift 7" tcp_nup --test-parameter upload_streams=1 This will note the value of sk_pacing_shift you are testing in the data file (so change that as appropriate), and you can vary the number of TCP streams by changing the upload_streams parameter. Note that in this case I'm assuming you are running Flent on the device with the kernel you are trying to test, so you want a TCP transfer going *from* the device. If not, change "tcp_nup" to "tcp_ndown" and "upload_streams" to "download_streams". Upload is netperf TCP_STREAM test, and download is TCP_MAERTS. When running the above command you'll get a summary output on the terminal that you can paste on the list; and also a data file to plot things form. For instance, you can do something like 'flent -p ping_cdf *.flent.gz' to get a CDF plot of all your test results afterwards. You are also very welcome to send me the .flent.gz data files and I'll take a look to make sure everything looks reasonable :) -Toke
