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. When I tested this, a pacing shift of 8 was quite close to optimal as well for ath10k. Why are you getting different results? > 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 Your tests do not include latency values; please try running a test that also measures latency. The tcp_nup test in Flent (https://flent.org) will do that, for instance. Also, is this a single TCP flow? -Toke
