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kadionik
Posts: 10
Registered: ‎06-02-2008
0

Re: Linux boot problem (xilinx ml403, linux-2.6-xlnx.git)

[ Edited ]

Hi,

 

Some very simple measurements on processing time (not on latency time) by using a H.263 decoder (tmndec) applied to an H.263 encoded file (51 H.263 frames).

For stressing the system, I've used stress tool: http://weather.ou.edu/~apw/projects/stress/

 

With standard Linux kernel for PowerPC/Xilinx (version 2.6.35):

Without CPU loading:

# cat godec                                                                
./tmndec -o5 stream.263 miss_dec.qcif

/bin # ./godec                                                                  
0.63 seconds, 51 frames, 80.95 fps

 

With CPU loading:

/bin # stress -i 20 -c 20 &                                                     
/bin # stress: info: [799] dispatching hogs: 20 cpu, 20 io, 0 vm, 0 hdd   
/bin # ./godec                                                                  
17.57 seconds, 51 frames, 2.90 fps  

 

With Xenomai Linux kernel for PowerPC/Xilinx (version 2.6.35 with Xenomai):

Without CPU loading:

/bin # ./godec                                                                  
0.65 seconds, 51 frames, 78.46 fps

 

With CPU loading:

/bin # stress -i 20 -c 20 &                                                     
/bin # stress: info: [799] dispatching hogs: 20 cpu, 20 io, 0 vm, 0 hdd  

/bin # ./godec                                                                  
19.20 seconds, 51 frames, 2.66 fps

Program executed as a POSIX RT thread with sched tool (SCHED_FIFO scheduling used by Xenomai for POSIX RT threads http://xenomai.org/index.php/Porting_POSIX_applications_to_Xenomai#Real-time_priorities):

/bin # sched -f 99 ./godec                                                      
0.65 seconds, 51 frames, 78.46 fps

 

With Xenomai extension, processing time for decoder as a Xenomai RT thread (SCHED_FIFO, priority 99) is bounded even with CPU loading...

 

Pat.