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Hi,
Thanks for the different answers I got concerning my problem of
allocating a huge 2d space 5000x5000 + a big population of agents
750000.
At the moment, I am running my Swarm model under winXP, 2.66Ghz P4, 512
MB RAM.
I have done some tests and I managed to instantiate a world of 3000x2700
2D grid + 2 Discrete2D planes + 1 million agents ! The simulation was
running slow but was running without crash or noticeable memory leaks.
But as soon as I wanted to have a 3000x2800 2D grid + (same parameters
as before), I had a crash. Here is a copy of the Dump I got:
------------------------------------------------------------------------
---------------------------
198 [sig] cart 1000 handle_exceptions: Exception:
STATUS_ACCESS_VIOLATION
Exception: STATUS_ACCESS_VIOLATION at eip=61009ACE
eax=00000000 ebx=0000065C ecx=0000065C edx=00000007 esi=04F8FE9C
edi=00000000
ebp=04F8FE84 esp=04F8FE6C
program=c:\Swarm-2.1.1\CartSimu\myCart190804\cart.exe
cs=001B ds=0023 es=0023 fs=0038 gs=0000 ss=0023
Stack trace:
Frame Function Args
04F8FE84 61009F35 (00000000, 00000000, 00000000, 0000073C)
04F8FEB4 61009F35 (00000000, 00000000, 00000000, 00000000)
04F8FF04 6100B3C7 (00000006, 00000000, 00000000, 000001F4)
04F8FF64 6103E747 (00000000, 00000001, 04F8FFB4, 6100324C)
04F8FFB4 61003252 (61080890, 00000001, 02A40003, 61080890)
990132 [sig] cart 1000 handle_exceptions: Exception:
STATUS_ACCESS_VIOLATION
1013736 [sig] cart 1000 handle_exceptions: Error while dumping state
(probably corrupted stack)
------------------------------------------------------------------------
--------------------------
To me, these results look quite promessing.
Thanks for the comments I got, I will also have a look at EcoLab and try
to have a comparative study on Swarm and Ecolab concerning the behaviour
of my model, robustness and speed.
Regards,
Vincent.
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Today's Topics:
1. huge memory allocation (Rouilly, Vincent)
2. Re: infinite loop (address@hidden)
3. Re: huge memory allocation (Bill Northcott)
4. Re: huge memory allocation (Ken Cline)
----------------------------------------------------------------------
Message: 1
Date: Fri, 20 Aug 2004 18:14:32 +0100
From: "Rouilly, Vincent" <address@hidden>
Subject: [Swarm-Support] huge memory allocation
To: <address@hidden>
Message-ID: <address@hidden>
Content-Type: text/plain; charset="us-ascii"
Hi,
First I would like to thank the people who are involved in Swarm for the
work that has been done. The platform is great and it is really helpful
in my research.
My question:
For my perfect simulation, I would like to create a 5000x5000 Grid2d
space + 3 Discrete2D planes.
Within this space, I would like to insert up to 750000 agents .... (huge
I know, and all as to be instantiated at the same time and for the same
amount of time).
Of course I have memory allocation problems at the moment.
How could I handle such a simulation ? Is there a way to increase the
memory allocation capacity of Swarm (or my computer) ? Are they any
limitations within swarm I should be aware of ? Using a cluster with
Swarm is possible ?
Many thanks,
Vincent
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Message: 3
Date: Sat, 21 Aug 2004 08:30:16 +1000
From: Bill Northcott <address@hidden>
Subject: Re: [Swarm-Support] huge memory allocation
To: Swarm Support <address@hidden>
Message-ID: <address@hidden>
Content-Type: text/plain; charset="us-ascii"
On 21/08/2004, at 3:14 AM, Rouilly, Vincent wrote:
My question:
For my perfect simulation, I would like to create a 5000x5000 Grid2d
space + 3 Discrete2D planes.
Within this space, I would like to insert up to 750000 agents ....
(huge I know, and all as to be instantiated at the same time and for
the same amount of time).
Of course I have memory allocation problems at the moment.
How could I handle such a simulation ? Is there a way to increase the
memory allocation capacity of Swarm (or my computer) ? Are they any
limitations within swarm I should be aware of ? Using a cluster with
Swarm is possible ?
Some more information would be helpful:
What is you current system? - CPU/RAM/OS etc
How big can you go? - Does 500x500x3 with 75000 agents work?
That way you can see the scale of your problem. My back of the
envelope feel is that there is no way you will get all that in VM on a
32 bit machine. Your talking 100 simultaneous HDTV displays with
every pixel calculated!
Maybe it work on a 64 bit platform, but you might need truckloads of
DRAM to stop the paging making everything horribly slow, and of course
there is the small issue of cost. It may still be horribly slow.
Otherwise, you try to box clever and see if you can break it into
subproblems with looser coupling. That is also what you would need to
do to run on a cluster. Swarm has no builtin cluster support, but
maybe you could help add it.
Finally you just might have to lower your expectations.
Bill Northcott
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Message: 4
Date: Fri, 20 Aug 2004 16:19:20 -0700 (PDT)
From: Ken Cline <address@hidden>
Subject: Re: [Swarm-Support] huge memory allocation
To: Swarm Support <address@hidden>
Message-ID: <address@hidden>
Content-Type: text/plain; charset=us-ascii
--- Bill Northcott <address@hidden> wrote:
On 21/08/2004, at 3:14 AM, Rouilly, Vincent wrote:
My question:
For my perfect simulation, I would like to create a 5000x5000 Grid2d
space + 3 Discrete2D planes.
Within this space, I would like to insert up to 750000 agents ....
(huge I know, and all as to be instantiated at the same time and for
the same amount of time).
Of course I have memory allocation problems at the moment.
How could I handle such a simulation ? Is there a way to increase
the
memory allocation capacity of Swarm (or my computer) ? Are they any
limitations within swarm I should be aware of ? Using a cluster with
Swarm is possible ?
Some more information would be helpful:
What is you current system? - CPU/RAM/OS etc
How big can you go? - Does 500x500x3 with 75000 agents work?
That way you can see the scale of your problem. My back of the
envelope feel is that there is no way you will get all that in VM on a
32 bit machine. Your talking 100 simultaneous HDTV displays with
every pixel calculated!
Maybe it work on a 64 bit platform, but you might need truckloads of
DRAM to stop the paging making everything horribly slow, and of course
there is the small issue of cost. It may still be horribly slow.
Otherwise, you try to box clever and see if you can break it into
subproblems with looser coupling. That is also what you would need to
do to run on a cluster. Swarm has no builtin cluster support, but
maybe you could help add it.
Finally you just might have to lower your expectations.
Bill Northcott
Another thought (which you've probably already considered)...
If your agents exist in only a fixed number of possible states[1] then
you could possibly minimize the memory consumption by following the
state machine design pattern. You'd still need at least one pointer per
agent, ie the handle to its current state, and hence you'll still likely
need to lower those expectations a bit. =:-(
Are you convinced that qualitatively different dynamics will emerge at
the 10^5 scale which don't exist with fewer agents? If not, then perhaps
a semantics-based solution will work, eg rename the Agent class as
"100Agents". Just a joke, but if your model has some type of agent
(affiliation) hierarchy then that a natural place to begin cutting it
up. (See previous discussions on this list related to clustering and
parallelization of models.)
Ken.
________
[1] Of course, any program (that terminates) has a finite number
of states... the tricky part is enumerating them. =8-]
=====
_________________________________________________________
Ken Cline W: (443) 287-2636
address@hidden
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