[PATCH v2 0/7] ath10k: add copy engine fast path support

[Roman Yeryomin]

On 1 February 2016 at 11:54, Roman Yeryomin <leroi.lists at gmail.com> wrote:
> On 31 January 2016 at 16:23, Manoharan, Rajkumar
> <rmanohar at qti.qualcomm.com> wrote:
>>>On 31 January 2016 at 08:31, Manoharan, Rajkumar
>>><rmanohar at qti.qualcomm.com> wrote:
>>>>>> Below patchset adds fast path support for uplink traffic by bypassing
>>>>>> HTC layer processing. This is enabled by making use of unused copy
>>>>>> engine 5 to receive HTT messages directly from HIF layer. From initial
>>>>>> validation in VHT80/5G mode TCP UL is improved to 900Mbps from ~840Mbps
>>>>>> in conducted test.
>>>>>>
>>>>>
>>>>>Hi Rajkumar,
>>>>>
>>>>>I'm very curious what hardware did you use to do the tests?
>>>>>Because with Dragonfly+Peregrine 3x3 I'm able to get only ~550Mbps :(
>>>>>
>>>>
>>>> Roman,
>>>>
>>>> It is verified in AP148 platform which IPQ8064 (1.4GHz dual core) platform.
>>>> Throughput will be lower in low end systems like AP135 (unicore processor).
>>>
>>> OK, but QSDK built with proprietary driver can reach 800Mbps at least.
>>> 900/800 Mbps difference is fine (ethernet software bridging is >900,
>>> e.g.) but 900/550 Mbps difference is not fine, there must be something
>>> ath10k is not doing or doing in a wrong way.
>>
>> While ago, Michal did an experiments to improve performance by offloading
>> encap/decap to firmware. Can you try with below patch set? I hope there might
>> be some conflicts since the change is outdated. Please make sure to enable
>> CONFIG_ATH10K_802_3_FORMAT switch.
>>
>> http://lists.infradead.org/pipermail/ath10k/2014-December/003935.html
>>
>> In one of my experiments, replacing netif_receive_skb to netif_rx in mac80211/rx.c
>> had improved rx performance in AP135. I dont have data right now. Can you give a try?
>
> After quick testing with 2x2 system I didn't see any significant improvement.
> Will test on 3x3 little bit later.

3x3 didn't perform better either. That's with 4.4 and backports from 2016-01-10.
One weird thing I see is about 15% idle cpu.
Any ideas?

Regards,
Roman