[v2] ath10k: snoc: enable threaded napi on WCN3990

  NAPI poll can be done in threaded context along with soft irq
context. Threaded context can be scheduled efficiently, thus
creating less of bottleneck during Rx processing. This patch is
to enable threaded NAPI on ath10k driver.

Based on testing, it was observed that on WCN3990, the CPU0 reaches
100% utilization when napi runs in softirq context. At the same
time the other CPUs are at low consumption percentage. This
does not allow device to reach its maximum throughput potential.
After enabling threaded napi, CPU load is balanced across all CPUs
and following improvments were observed:
- UDP_RX increase by ~22-25%
- TCP_RX increase by ~15%

Here are some of the additional raw data with and without threaded napi:
==================================================
udp_rx(Without threaded NAPI)
435.98+-5.16 : Channel 44
439.06+-0.66 : Channel 157

udp_rx(With threaded NAPI)
509.73+-41.03 : Channel 44
549.97+-7.62 : Channel 157
===================================================
udp_tx(Without threaded NAPI)
461.31+-0.69  : Channel 44
461.46+-0.78 : Channel 157

udp_tx(With threaded NAPI)
459.20+-0.77 : Channel 44
459.78+-1.08 : Channel 157
===================================================
tcp_rx(Without threaded NAPI)
472.63+-2.35 : Channel 44
469.29+-6.31 : Channel 157

tcp_rx(With threaded NAPI)
498.49+-2.44 : Channel 44
541.14+-40.65 : Channel 157
===================================================
tcp_tx(Without threaded NAPI)
317.34+-2.37 : Channel 44
317.01+-2.56 : Channel 157

tcp_tx(With threaded NAPI)
371.34+-2.36 : Channel 44
376.95+-9.40 : Channel 157
===================================================

Tested-on: WCN3990 hw1.0 SNOC WLAN.HL.3.2.2-00696-QCAHLSWMTPL-1
Signed-off-by: Abhishek Kumar <kuabhs@chromium.org>
---

Changes in v2:
- Removed the hw param checks to add dev_set_threaded() to snoc.c
- Added some more test data in the commit message.

 drivers/net/wireless/ath/ath10k/snoc.c | 1 +
 1 file changed, 1 insertion(+)
  

Hi Kale,

Gentle reminder for your comments.

Thanks
Abhishek

On Thu, Feb 2, 2023 at 4:02 PM Abhishek Kumar <kuabhs@chromium.org> wrote:
>
> NAPI poll can be done in threaded context along with soft irq
> context. Threaded context can be scheduled efficiently, thus
> creating less of bottleneck during Rx processing. This patch is
> to enable threaded NAPI on ath10k driver.
>
> Based on testing, it was observed that on WCN3990, the CPU0 reaches
> 100% utilization when napi runs in softirq context. At the same
> time the other CPUs are at low consumption percentage. This
> does not allow device to reach its maximum throughput potential.
> After enabling threaded napi, CPU load is balanced across all CPUs
> and following improvments were observed:
> - UDP_RX increase by ~22-25%
> - TCP_RX increase by ~15%
>
> Here are some of the additional raw data with and without threaded napi:
> ==================================================
> udp_rx(Without threaded NAPI)
> 435.98+-5.16 : Channel 44
> 439.06+-0.66 : Channel 157
>
> udp_rx(With threaded NAPI)
> 509.73+-41.03 : Channel 44
> 549.97+-7.62 : Channel 157
> ===================================================
> udp_tx(Without threaded NAPI)
> 461.31+-0.69  : Channel 44
> 461.46+-0.78 : Channel 157
>
> udp_tx(With threaded NAPI)
> 459.20+-0.77 : Channel 44
> 459.78+-1.08 : Channel 157
> ===================================================
> tcp_rx(Without threaded NAPI)
> 472.63+-2.35 : Channel 44
> 469.29+-6.31 : Channel 157
>
> tcp_rx(With threaded NAPI)
> 498.49+-2.44 : Channel 44
> 541.14+-40.65 : Channel 157
> ===================================================
> tcp_tx(Without threaded NAPI)
> 317.34+-2.37 : Channel 44
> 317.01+-2.56 : Channel 157
>
> tcp_tx(With threaded NAPI)
> 371.34+-2.36 : Channel 44
> 376.95+-9.40 : Channel 157
> ===================================================
>
> Tested-on: WCN3990 hw1.0 SNOC WLAN.HL.3.2.2-00696-QCAHLSWMTPL-1
> Signed-off-by: Abhishek Kumar <kuabhs@chromium.org>
> ---
>
> Changes in v2:
> - Removed the hw param checks to add dev_set_threaded() to snoc.c
> - Added some more test data in the commit message.
>
>  drivers/net/wireless/ath/ath10k/snoc.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/net/wireless/ath/ath10k/snoc.c b/drivers/net/wireless/ath/ath10k/snoc.c
> index cfcb759a87de..0f6d2f67ff6b 100644
> --- a/drivers/net/wireless/ath/ath10k/snoc.c
> +++ b/drivers/net/wireless/ath/ath10k/snoc.c
> @@ -927,6 +927,7 @@ static int ath10k_snoc_hif_start(struct ath10k *ar)
>
>         bitmap_clear(ar_snoc->pending_ce_irqs, 0, CE_COUNT_MAX);
>
> +       dev_set_threaded(&ar->napi_dev, true);
>         ath10k_core_napi_enable(ar);
>         ath10k_snoc_irq_enable(ar);
>         ath10k_snoc_rx_post(ar);
> --
> 2.39.1.519.gcb327c4b5f-goog
>
  

Abhishek Kumar <kuabhs@chromium.org> writes:

> Gentle reminder for your comments.

A gentle reminder to avoid sending gentle reminders :) For example, I
currently have 103 patches in patchwork and if everyone send gentle
reminders that's a lot of unnecessary email. So please avoid sending
unnecessary emails. "gentle reminders" don't help, quite the opposite.

Unfortunately sometimes it takes time before I'm able to look at
patches, but if the patch is in patchwork in an active state I will look
at them eventually. More info here:

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches#checking_state_of_patches_from_patchwork
  

Abhishek Kumar <kuabhs@chromium.org> wrote:

> NAPI poll can be done in threaded context along with soft irq
> context. Threaded context can be scheduled efficiently, thus
> creating less of bottleneck during Rx processing. This patch is
> to enable threaded NAPI on ath10k driver.
> 
> Based on testing, it was observed that on WCN3990, the CPU0 reaches
> 100% utilization when napi runs in softirq context. At the same
> time the other CPUs are at low consumption percentage. This
> does not allow device to reach its maximum throughput potential.
> After enabling threaded napi, CPU load is balanced across all CPUs
> and following improvments were observed:
> - UDP_RX increase by ~22-25%
> - TCP_RX increase by ~15%
> 
> Here are some of the additional raw data with and without threaded napi:
> ==================================================
> udp_rx(Without threaded NAPI)
> 435.98+-5.16 : Channel 44
> 439.06+-0.66 : Channel 157
> 
> udp_rx(With threaded NAPI)
> 509.73+-41.03 : Channel 44
> 549.97+-7.62 : Channel 157
> ===================================================
> udp_tx(Without threaded NAPI)
> 461.31+-0.69  : Channel 44
> 461.46+-0.78 : Channel 157
> 
> udp_tx(With threaded NAPI)
> 459.20+-0.77 : Channel 44
> 459.78+-1.08 : Channel 157
> ===================================================
> tcp_rx(Without threaded NAPI)
> 472.63+-2.35 : Channel 44
> 469.29+-6.31 : Channel 157
> 
> tcp_rx(With threaded NAPI)
> 498.49+-2.44 : Channel 44
> 541.14+-40.65 : Channel 157
> ===================================================
> tcp_tx(Without threaded NAPI)
> 317.34+-2.37 : Channel 44
> 317.01+-2.56 : Channel 157
> 
> tcp_tx(With threaded NAPI)
> 371.34+-2.36 : Channel 44
> 376.95+-9.40 : Channel 157
> ===================================================
> 
> Tested-on: WCN3990 hw1.0 SNOC WLAN.HL.3.2.2-00696-QCAHLSWMTPL-1
> Signed-off-by: Abhishek Kumar <kuabhs@chromium.org>
> Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>

Patch applied to ath-next branch of ath.git, thanks.

8c68fe00344c wifi: ath10k: snoc: enable threaded napi on WCN3990