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.
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
Signed-off-by: Wen Gong <wgong@xxxxxxxxxxxxxx>
---
drivers/net/wireless/ath/ath10k/mac.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c
index f31ae3b..40d24c1 100644
--- a/drivers/net/wireless/ath/ath10k/mac.c
+++ b/drivers/net/wireless/ath/ath10k/mac.c
@@ -8348,6 +8348,8 @@ int ath10k_mac_register(struct ath10k *ar)
ar->hw->wiphy->max_scan_ssids = WLAN_SCAN_PARAMS_MAX_SSID;
ar->hw->wiphy->max_scan_ie_len = WLAN_SCAN_PARAMS_MAX_IE_LEN;
+ ar->hw->tx_sk_pacing_shift = 6;
+
ar->hw->vif_data_size = sizeof(struct ath10k_vif);
ar->hw->sta_data_size = sizeof(struct ath10k_sta);
ar->hw->txq_data_size = sizeof(struct ath10k_txq);
--
1.9.1
