[Avrora] Avrora does not run in Real-Time
rodolfo de paz
rodolfo.depaz at cit.ie
Wed Jan 28 03:51:14 PST 2009
My experience is that Avrora cannot run more that 50 nodes in my Dell Latitude D630. Being always the problem running out of memory. Increasing the heap space with java -Xms<initial heap size> -Xmx<maximum heap size> commands improves that a bit but certainly not up to 100nodes.
I think it would be a good idea to allow the connection of emulated/real nodes through TCP sockets to increase the number of nodes in the network. This would follow somehow the freemote emulator (http://unine08.iraph.net/IMG/pdf/article_wip.pdf)
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
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?
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.
> 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?
> 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.
> 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:
> 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
> 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
> serial ports using TCP communication. But, due to the time
> between Avrora and PC-clock, I cannot perform any real-time
> Could you guys let me know why it is and how to solve it?
> 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>>
> 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
Paul J. Shin (Joonhwa Shin)
Graduate Research Assistant
Robot Vision Lab
School of Electrical and Computer Engineering
"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
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