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From: Felix Fietkau <nbd@nbd.name>
To: Rakesh Pillai <pillair@codeaurora.org>,
	'Ben Greear' <greearb@candelatech.com>,
	'Brian Norris' <briannorris@chromium.org>
Cc: 'Johannes Berg' <johannes@sipsolutions.net>,
	'Rajkumar Manoharan' <rmanohar@codeaurora.org>,
	'ath10k' <ath10k@lists.infradead.org>,
	'linux-wireless' <linux-wireless@vger.kernel.org>,
	'Linux Kernel' <linux-kernel@vger.kernel.org>,
	'Kalle Valo' <kvalo@codeaurora.org>,
	"'David S. Miller'" <davem@davemloft.net>,
	'Jakub Kicinski' <kuba@kernel.org>,
	netdev@vger.kernel.org, 'Doug Anderson' <dianders@chromium.org>,
	'Evan Green' <evgreen@chromium.org>
Subject: Re: [RFC 2/7] ath10k: Add support to process rx packet in thread
Date: Thu, 25 Mar 2021 11:33:53 +0100	[thread overview]
Message-ID: <e7dc6d97-bab2-3bd4-685a-a8b5e25c18d9@nbd.name> (raw)
In-Reply-To: <003701d7215b$a44ae030$ece0a090$@codeaurora.org>


On 2021-03-25 10:45, Rakesh Pillai wrote:
> Hi Felix / Ben,
> 
> In case of ath10k (snoc based targets), we have a lot of processing in the NAPI context.
> Even moving this to threaded NAPI is not helping much due to the load.
> 
> Breaking the tasks into multiple context (with the patch series I posted) is helping in improving the throughput.
> With the current rx_thread based approach, the rx processing is broken into two parallel contexts
> 1) reaping the packets from the HW
> 2) processing these packets list and handing it over to mac80211 (and later to the network stack)
> 
> This is the primary reason for choosing the rx thread approach.
Have you considered the possibility that maybe the problem is that the
driver doing too much work?
One example is that you could take advantage of the new 802.3 decap
offload to simplify rx processing. Worked for me on mt76 where a
dual-core 1.3 GHz A64 can easily handle >1.8 Gbps local TCP rx on a
single card, without the rx NAPI thread being the biggest consumer of
CPU cycles.

And if you can't do that and still consider all of the metric tons of
processing work necessary, you could still do this:
On interrupts, spawn a processing thread that traverses the ring and
does the preparation work (instead of NAPI).
From that thread you schedule the threaded NAPI handler that processes
these packets further and hands them to mac80211.
To keep the load somewhat balanced, you can limit the number of
pre-processed packets in the ring.

- Felix

WARNING: multiple messages have this Message-ID
From: Felix Fietkau <nbd@nbd.name>
To: Rakesh Pillai <pillair@codeaurora.org>,
	'Ben Greear' <greearb@candelatech.com>,
	'Brian Norris' <briannorris@chromium.org>
Cc: 'Johannes Berg' <johannes@sipsolutions.net>,
	'Rajkumar Manoharan' <rmanohar@codeaurora.org>,
	'ath10k' <ath10k@lists.infradead.org>,
	'linux-wireless' <linux-wireless@vger.kernel.org>,
	'Linux Kernel' <linux-kernel@vger.kernel.org>,
	'Kalle Valo' <kvalo@codeaurora.org>,
	"'David S. Miller'" <davem@davemloft.net>,
	'Jakub Kicinski' <kuba@kernel.org>,
	netdev@vger.kernel.org, 'Doug Anderson' <dianders@chromium.org>,
	'Evan Green' <evgreen@chromium.org>
Subject: Re: [RFC 2/7] ath10k: Add support to process rx packet in thread
Date: Thu, 25 Mar 2021 11:33:53 +0100	[thread overview]
Message-ID: <e7dc6d97-bab2-3bd4-685a-a8b5e25c18d9@nbd.name> (raw)
In-Reply-To: <003701d7215b$a44ae030$ece0a090$@codeaurora.org>


On 2021-03-25 10:45, Rakesh Pillai wrote:
> Hi Felix / Ben,
> 
> In case of ath10k (snoc based targets), we have a lot of processing in the NAPI context.
> Even moving this to threaded NAPI is not helping much due to the load.
> 
> Breaking the tasks into multiple context (with the patch series I posted) is helping in improving the throughput.
> With the current rx_thread based approach, the rx processing is broken into two parallel contexts
> 1) reaping the packets from the HW
> 2) processing these packets list and handing it over to mac80211 (and later to the network stack)
> 
> This is the primary reason for choosing the rx thread approach.
Have you considered the possibility that maybe the problem is that the
driver doing too much work?
One example is that you could take advantage of the new 802.3 decap
offload to simplify rx processing. Worked for me on mt76 where a
dual-core 1.3 GHz A64 can easily handle >1.8 Gbps local TCP rx on a
single card, without the rx NAPI thread being the biggest consumer of
CPU cycles.

And if you can't do that and still consider all of the metric tons of
processing work necessary, you could still do this:
On interrupts, spawn a processing thread that traverses the ring and
does the preparation work (instead of NAPI).
From that thread you schedule the threaded NAPI handler that processes
these packets further and hands them to mac80211.
To keep the load somewhat balanced, you can limit the number of
pre-processed packets in the ring.

- Felix

_______________________________________________
ath10k mailing list
ath10k@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/ath10k

  reply	other threads:[~2021-03-25 10:34 UTC|newest]

Thread overview: 96+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-21 17:14 [RFC 0/7] Add support to process rx packets " Rakesh Pillai
2020-07-21 17:14 ` Rakesh Pillai
2020-07-21 17:14 ` [RFC 1/7] mac80211: Add check for napi handle before WARN_ON Rakesh Pillai
2020-07-21 17:14   ` Rakesh Pillai
2020-07-22 12:56   ` Johannes Berg
2020-07-22 12:56     ` Johannes Berg
2020-07-23 18:26     ` Rakesh Pillai
2020-07-23 18:26       ` Rakesh Pillai
2020-07-23 20:06       ` Johannes Berg
2020-07-23 20:06         ` Johannes Berg
2020-07-24  6:21         ` Rakesh Pillai
2020-07-24  6:21           ` Rakesh Pillai
2020-07-26 16:19         ` Rakesh Pillai
2020-07-26 16:19           ` Rakesh Pillai
2020-07-30 12:40           ` Johannes Berg
2020-07-30 12:40             ` Johannes Berg
2020-07-21 17:14 ` [RFC 2/7] ath10k: Add support to process rx packet in thread Rakesh Pillai
2020-07-21 17:14   ` Rakesh Pillai
2020-07-21 21:53   ` Rajkumar Manoharan
2020-07-21 21:53     ` Rajkumar Manoharan
2020-07-22 12:27     ` Felix Fietkau
2020-07-22 12:27       ` Felix Fietkau
2020-07-22 12:55       ` Johannes Berg
2020-07-22 12:55         ` Johannes Berg
2020-07-22 13:00         ` Felix Fietkau
2020-07-22 13:00           ` Felix Fietkau
2020-07-23  6:09           ` Rajkumar Manoharan
2020-07-23  6:09             ` Rajkumar Manoharan
2021-03-22 23:57           ` Ben Greear
2021-03-22 23:57             ` Ben Greear
2021-03-23  1:20             ` Brian Norris
2021-03-23  1:20               ` Brian Norris
2021-03-23  3:01               ` Ben Greear
2021-03-23  3:01                 ` Ben Greear
2021-03-23  7:45                 ` Felix Fietkau
2021-03-23  7:45                   ` Felix Fietkau
2021-03-25  9:45                   ` Rakesh Pillai
2021-03-25  9:45                     ` Rakesh Pillai
2021-03-25 10:33                     ` Felix Fietkau [this message]
2021-03-25 10:33                       ` Felix Fietkau
2020-07-23 18:25     ` Rakesh Pillai
2020-07-23 18:25       ` Rakesh Pillai
2020-07-24 23:11       ` Jacob Keller
2020-07-24 23:11         ` Jacob Keller
2020-07-21 17:14 ` [RFC 3/7] ath10k: Add module param to enable rx thread Rakesh Pillai
2020-07-21 17:14   ` Rakesh Pillai
2020-07-21 17:14 ` [RFC 4/7] ath10k: Do not exhaust budget on process tx completion Rakesh Pillai
2020-07-21 17:14   ` Rakesh Pillai
2020-07-21 17:14 ` [RFC 5/7] ath10k: Handle the rx packet processing in thread Rakesh Pillai
2020-07-21 17:14   ` Rakesh Pillai
2020-07-21 17:14 ` [RFC 6/7] ath10k: Add deliver to stack from thread context Rakesh Pillai
2020-07-21 17:14   ` Rakesh Pillai
2020-07-21 17:14 ` [RFC 7/7] ath10k: Handle rx thread suspend and resume Rakesh Pillai
2020-07-21 17:14   ` Rakesh Pillai
2020-07-23 23:06   ` Sebastian Gottschall
2020-07-23 23:06     ` Sebastian Gottschall
2020-07-24  6:19     ` Rakesh Pillai
2020-07-24  6:19       ` Rakesh Pillai
2020-07-21 17:25 ` [RFC 0/7] Add support to process rx packets in thread Andrew Lunn
2020-07-21 17:25   ` Andrew Lunn
2020-07-21 18:05   ` Florian Fainelli
2020-07-21 18:05     ` Florian Fainelli
2020-07-23 18:21     ` Rakesh Pillai
2020-07-23 18:21       ` Rakesh Pillai
2020-07-23 19:02       ` Florian Fainelli
2020-07-23 19:02         ` Florian Fainelli
2020-07-24  6:20         ` Rakesh Pillai
2020-07-24  6:20           ` Rakesh Pillai
2020-07-24 22:28           ` Florian Fainelli
2020-07-24 22:28             ` Florian Fainelli
2020-07-22  9:12   ` David Laight
2020-07-22  9:12     ` David Laight
2020-07-25  8:16     ` Hillf Danton
2020-07-25 10:38       ` Sebastian Gottschall
2020-07-25 10:38         ` Sebastian Gottschall
2020-07-25 12:25         ` Hillf Danton
2020-07-25 14:08         ` Sebastian Gottschall
2020-07-25 14:08           ` Sebastian Gottschall
2020-07-25 14:57           ` Hillf Danton
2020-07-25 15:41             ` Sebastian Gottschall
2020-07-25 15:41               ` Sebastian Gottschall
2020-07-26 11:16               ` David Laight
2020-07-26 11:16                 ` David Laight
2020-07-28 16:59                 ` Rakesh Pillai
2020-07-28 16:59                   ` Rakesh Pillai
2020-07-29  1:34                   ` Hillf Danton
2020-07-25 17:57       ` Felix Fietkau
2020-07-25 17:57         ` Felix Fietkau
2020-07-26  1:22         ` Hillf Danton
2020-07-26  8:10           ` Felix Fietkau
2020-07-26  8:10             ` Felix Fietkau
2020-07-26  8:32             ` Hillf Danton
2020-07-26  8:59               ` Felix Fietkau
2020-07-26  8:59                 ` Felix Fietkau
2020-07-22 16:20   ` Jakub Kicinski
2020-07-22 16:20     ` Jakub Kicinski

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