[Dev] Tizen use of FIFO & Nice

Clark, Joel joel.clark at intel.com
Thu Dec 12 20:01:24 GMT 2013


For IVI, we are expecting several thousand sensor updates per second, with nearly 200 different types of sensor data.  Think about data on the engine, transmission, wheels, brakes, windows, doors, seats, radar updates on proximity, etc. 

Regards
Joel


-----Original Message-----
From: Kok, Auke-jan H [mailto:auke-jan.h.kok at intel.com] 
Sent: Thursday, December 12, 2013 11:35 AM
To: Clark, Joel
Cc: dev at lists.tizen.org
Subject: Re: [Dev] Tizen use of FIFO & Nice

On Thu, Dec 12, 2013 at 9:38 AM, Clark, Joel <joel.clark at intel.com> wrote:
> Why does Tizen use FIFO and NICE?  There are more than 500 threads 
> with FIFO and NICE affecting the performance of critical elements for 
> reading sensor data and updating location etc.

Mostly to prioritize screen update refresh rates. Do you really need your GPS location to update within a 20ms interval?

Humans can see a single frame drop, easily. Audio is critical too.
Sensor data (apart from touch) is almost irrelevant at the scale that humans can detect.

Also, even with Nice values set high, applications can still be low latency. They do not necessarily conflict.

Auke


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