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Re: Phone performance

 

On Sun, Aug 16, 2015 at 8:17 PM, Chunsang Jeong <
chunsang.jeong@xxxxxxxxxxxxx> wrote:

>
>
> On Sat, Aug 15, 2015 at 12:32 AM, Alberto Aguirre <
> alberto.aguirre@xxxxxxxxxxxxx> wrote:
>
>> That will also be the result of the scaling governor. I was surprised too
>> that arale (Meizu) only has an interactive governor available.
>> It's quite hard to measure performance consistently and effectively with
>> such a governor (specially for comparison purposes).
>>
>> >I'm more concerned about how can we keep phone graphics performing as
>> well as they do during touches, even when we're not touching them?
>> I don't think there's escaping the fact that we will need to tune the
>> governor to match the Ubuntu workload.
>>
>>
>>
>>
>> On Fri, Aug 14, 2015 at 3:55 AM, Daniel van Vugt <
>> daniel.van.vugt@xxxxxxxxxxxxx> wrote:
>>
>>> It's not just frequency either. On arale (Meizu) for example, smoothness
>>> correlates directly with whether multiple CPU cores are online or not:
>>>
>>>   cat /sys/devices/system/cpu/online
>>>
>>> Usually the kernel only keeps one core online, which makes Unity8
>>> stutter. But if you touch it enough then the second core (out of eight)
>>> comes online and everything is smooth. I wonder if more aggressive use of
>>> threads might help...
>>>
>>>
>>>
>>> On 14/08/15 16:48, Daniel van Vugt wrote:
>>>
>>>> Hi all,
>>>>
>>>> In testing performance optimisations on various phones, I keep running
>>>> into an annoying hurdle.
>>>>
>>>> Although you can optimise your Mir server/clients in such a way that
>>>> they're smoother more often, there's an additional variable outside of
>>>> Mir and Unity that gets in the way. That seems to be frequency scaling
>>>> done by the kernel. Sometimes on desktops too, but I'm mostly concerned
>>>> about phones here.
>>>>
>>>> I find it suspicious that on some devices you can turn stuttering into
>>>> smoothness just but touching the screen a lot. But the smoothness soon
>>>> goes away when you're not touching the screen. In the extreme case, if
>>>> you're logged into the phone remotely you will also notice the system
>>>> can become unusably slow when the screen has turned off. That's useful
>>>> for a real phone's battery life, but it serves to illustrate that the
>>>> kernel is doing a lot behind the scenes. I'm more concerned about how
>>>> can we keep phone graphics performing as well as they do during touches,
>>>> even when we're not touching them?
>>>>
>>>>
> I'm not sure these are what you want to, but if you're testing on Arale,
> you can enable cpus by
>  /proc/hps/num_base_perf_serv [# of little] [# of bigs]
>    ex) sudo /proc/hps/num_base_perf_serv 2 2 (2 littles and 2 bigs)
>
sorry, it works as;
sudo echo [# of little] [# of bigs]  > /proc/hps/num_base_perf_serv
      ex) sudo echo 2 2 /proc/hps/hum_base_perf_serv (2 littles and 2 bigs)

> and also can set gpu with the max freq by
>   echo 0 > /sys/module/pvrsrvkm/parameters/gpu_dvfs_enable
> (though I'm recommending this only for testing.)
>
> - Daniel
>>>>
>>>>
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>>>
>>
>>
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>>
>
>
> --
> Chunsang(Paul) Jeong
>



-- 
Chunsang(Paul) Jeong

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