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Old 06-10-2010, 11:00 PM   #1
pratibhasri
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xenomai giving higher latencies


hii
i am still not sure which is better to get hard real time performance on linux.
theoretically looks xenomai/rtai is better than Preempt RT
but when i tried i found xenomai is giving higher and more frequent latencies compared to Preempt RT patch
may be i am missing someting during configuring xenomai
i have tried with linux 2.6.23
xenomai 2.4.1 and preempt rt-11 patch
can anybody guide what i am missing in xenomai installation
i made following conf edits for xenomai
enable smi workaround - y
globally disable smi -y
power management support - n
cpu freq scaling -n

is it possible to put both xenomai and preempt rt patch together
i tried the abice two but they are not going together
 
Old 06-14-2010, 03:04 PM   #2
nini09
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What's your testing tool, benchmark? Do you change xenomai configuration and compare them again?
 
Old 06-15-2010, 02:25 AM   #3
pratibhasri
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i am toggling one hardware output bit
and also comparing with gettimeofday function
 
Old 06-16-2010, 02:31 PM   #4
nini09
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The kernel response time is the sum of the following times :

Interrupt latency
Interrupt handler duration
Scheduler Latency
Scheduling Duration

What time do you talk about?
 
Old 06-21-2010, 03:11 AM   #5
pratibhasri
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i am talking of the total latency only
that is said to be reduced for xenomai linux
as setting and resetting one port bit in the application on each timer interrupt will involve all latencies.
 
Old 06-24-2010, 03:18 PM   #6
nini09
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What API in application do you use? Do you use real time API?
 
Old 06-28-2010, 02:43 AM   #7
pratibhasri
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yes,
i am using the RTDM only for xenomai.
 
  


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