[Avrora] Avrora does not run in Real-Time

[Paul J. Shin]

Hi Rodolfo,

I couldn't solve the problem. Thus, I just try to upgrade the memory of 
my machine from 4GB to 8GB. I am ordering some memories from Amazon..

But, my colleague found an interesting fact. When he ran a simple blink 
application on the motes on the Avorora, then the CPU usage went up to 
100% with faster operation. But, if he ran some other apps that requires 
serial monitor, then the CPU went only up to 50~70% as what I got 
before. So, we are suspecting that serial monitor is one of the major 
cause of slowing down Avrora.

But unfortunately, serial monitor is an essential block of our simulator 
to hook up with Avrora. So, now only thing that I can do is just to slow 
down my simulator so that it runs as slowly as Avrora does, that is, 
time synchronization. It is not the ultimate solution, but it somehow 
works in that way. :(

If you have better ideas, then please let me know.

Thanks,
Paul



rodolfo de paz wrote:
> Hi Paul,
>
> Did you finally get any solution to improve Avrora performance? 
>
> Thanks,
>
> Rodolfo.
>
> -----Original Message-----
> From: avrora-bounces at lists.ucla.edu on behalf of Paul J. Shin
> Sent: Wed 28/01/2009 6:30 AM
> To: Zainul Charbiwala
> Cc: Mailing list for Avrora simulator users and developers.
> Subject: Re: [Avrora] Avrora does not run in Real-Time
>  
>
> Hi Zainul,
>
> I just tested my simulator again with 120 nodes on my machine.
> All of the four cores run at averagely 50% rate (per core), and the 
> memory usage was 80% of total 4 GB.
> It seems that insufficient memory may be one reason that slows down 
> Avrora. However, since it didn't go up to 100%, it may not be the main 
> reason. This is the biggest headache to me in these days.
>
> Is there anybody who can help me? Could you help me out, Ben?
>
> Thanks,
> Paul
>
>
>
> Zainul Charbiwala wrote:
>   
>> Hi Paul,
>>
>> I'm adding the thread back to the mailing list. I'm not sure how many 
>> users have actually gone to a 100 nodes but I do remember that Ben had 
>> tested Avrora on a beefy Sun machine with up to 1000 nodes (please 
>> correct me, Ben).
>>
>> As far as I know, Avrora's current design does not handle multiple 
>> CPUs or cores. The 20% utilization that you see might be because on 
>> your quad core, one core is doing all the heavy lifting. Try running 
>> top and then pressing '1' to get the per core CPU usage.
>>
>> Zainul.
>>
>>
>> On Tue, Jan 27, 2009 at 4:43 PM, Paul J. Shin <paulshin at purdue.edu 
>> <mailto:paulshin at purdue.edu>> wrote:
>>
>>
>>     Hi Zainul,
>>
>>     Thank you for your suggestion.
>>     Right now my machine has 4GB of memory and the CPU is 3GHz
>>     Quad-core. Do you think the reason is still on the memory? Do you
>>     think it would get better if I increase the memory?
>>
>>     Thanks,
>>     Paul
>>
>>
>>
>>
>>     Zainul Charbiwala wrote:
>>
>>         Hi Paul,
>>
>>         With a 100 node simulation, your bottleneck is memory (or
>>         memory bandwidth) and not CPU.
>>
>>         I would suggest that your external simulator slow itself down,
>>         if you can't reduce the number of nodes.
>>
>>         Zainul.
>>
>>         On Tue, Jan 27, 2009 at 2:24 PM, Paul J. Shin
>>         <paulshin at purdue.edu <mailto:paulshin at purdue.edu>
>>         <mailto:paulshin at purdue.edu <mailto:paulshin at purdue.edu>>> wrote:
>>
>>
>>
>>         Hi,
>>
>>         I got a weired case when I run Avrora.
>>
>>         It makes sense that Avrora does not run in real-time if my
>>         machine is
>>         not fast enough so the CPU rate goes upto 100% when I run Avrora.
>>         But, for me it doesn't make sense that Avrora does not run in
>>         real-time
>>         with 20% of CPU occupancy. It always happens regardless of whether
>>         I put
>>         -real-time flag or not.
>>
>>         Why I say that Avrora does not run in real-time is because
>>         although I
>>         have run Avrora for about 2 hours, the elapsed time in Avrora
>>         is only
>>         about 5 minutes with 100 nodes.
>>
>>         I have made some other simulator that communicate with Avrora
>>         through
>>         serial ports using TCP communication. But, due to the time
>>         discrepancy
>>         between Avrora and PC-clock, I cannot perform any real-time
>>         simulation.
>>
>>         Could you guys let me know why it is and how to solve it?
>>
>>         Thanks,
>>         Paul
>>
>>
>>         _______________________________________________
>>         Avrora mailing list
>>         Avrora at lists.ucla.edu <mailto:Avrora at lists.ucla.edu>
>>         <mailto:Avrora at lists.ucla.edu <mailto:Avrora at lists.ucla.edu>>
>>
>>         http://lists.ucla.edu/cgi-bin/mailman/listinfo/avrora
>>
>>
>>
>>     -- 
>>     ==================================
>>     Paul J. Shin (Joonhwa Shin)
>>     Graduate Research Assistant
>>     Robot Vision Lab
>>     School of Electrical and Computer Engineering
>>     Purdue University
>>     "Those who are wise will shine like the brightness of the heavens,
>>     and those who lead many to righteousness like the stars for ever
>>     and ever." - DAN 12:3
>>     ==============================================
>>
>>     ?
>>
>>     ?
>>
>>
>>     
>
>