Big Image Tests

> Today I tried to find out if it would be possible to allocate a large amount of memory in a VM.
>
> I used the official 32-bit VM (http://gforge.inria.fr/frs/download.php/29042/CogVM-Unix-13307.zip) and a Pharo 1.3 (http://gforge.inria.fr/frs/download.php/29273/Pharo-1.3-13315.zip) derived image on Ubuntu 11.04 (x86_64) Amazon AWS EC2 m1.large instance (about 8Gb RAM) and the following bash and Smalltalk scripts:
>
> run.sh
>
> #!/bin/bash
> script_home=$(dirname $0)
> script_home=$(cd $script_home&&  pwd)
> image=$script_home/pharo-t3.image
> script=$script_home/run.st
> args=$*
> vm=$script_home/bin/CogVM
> options="-mmap 1536m -vm-display-null -vm-sound-null"
> #echo $vm $options $image $script $args
> $vm $options $image $script $args
>
> run.st
>
> | args size monolithic object |
>
> FileStream stdout wantsLineEndConversion: true.
>
> Smalltalk garbageCollect.
>
> FileStream stdout
>    nextPutAll: 'Running run.st with args: ';
>    nextPutAll: Smalltalk commandLine arguments printString;
>    cr;
>    nextPutAll: Smalltalk vmStatisticsReportString.
>
> args := Smalltalk commandLine arguments.
> size := args first asInteger.
> monolithic := (args size>  1 and: [ args second = 'monolithic' ]).
>
> monolithic
>    ifTrue: [
>      object := ByteArray ofSize: size * 1024 * 1024 ]
>    ifFalse: [
>      object := Array ofSize: size * 1024.
>      1 to: size * 1024 do: [ :each |
>        object at: each put: (ByteArray ofSize: 1024) ] ].
>
> Smalltalk garbageCollect.
>
> FileStream stdout
>    nextPutAll: 'Allocation of a size ';
>    print: object size;
>    space;
>    print: object class;
>    nextPutAll: ' OK';
>    cr;
>    nextPutAll: Smalltalk vmStatisticsReportString.
>
> Smalltalk quitPrimitive.
>
> These were the results trying to allocate 1GB:
>
> $ ./run.sh 1024
> Running run.st with args: #('1024')
> uptime 0h0m0s
> memory 49,103,224 bytes
> old 36,625,732 bytes (74.60000000000001%)
> young 9,812 bytes (0.0%)
> used 36,635,544 bytes (74.60000000000001%)
> free 12,467,680 bytes (25.400000000000002%)
> GCs 8 (90ms between GCs)
> full 2 totalling 212ms (29.400000000000002% uptime), avg 106.0ms
> incr 6 totalling 10ms (1.4000000000000001% uptime), avg 1.7000000000000002ms
> tenures 0
> Allocation of a size 1048576 Array OK
> uptime 0h0m26s
> memory -1,007,414,928 bytes
> old -1,020,337,428 bytes (101.30000000000001%)
> young 5,888 bytes (0.0%)
> used -1,020,331,540 bytes (101.30000000000001%)
> free 12,916,612 bytes (-1.3%)
> GCs 590 (44ms between GCs)
> full 62 totalling 14,735ms (56.6% uptime), avg 237.70000000000002ms
> incr 528 totalling 10,225ms (39.300000000000004% uptime), avg 19.400000000000002ms
> tenures 519 (avg 1 GCs/tenure)
> Since last view 582 (44ms between GCs)
> uptime 25.3s
> full 60 totalling 14,523ms (57.400000000000006% uptime), avg 242.10000000000002ms
> incr 522 totalling 10,215ms (40.300000000000004% uptime), avg 19.6ms
> tenures 519 (avg 1 GCs/tenure)
>
> $ ./run.sh 1024 monolithic
> Running run.st with args: #('1024' 'monolithic')
> uptime 0h0m0s
> memory 49,103,216 bytes
> old 36,627,976 bytes (74.60000000000001%)
> young 9,844 bytes (0.0%)
> used 36,637,820 bytes (74.60000000000001%)
> free 12,465,396 bytes (25.400000000000002%)
> GCs 8 (46ms between GCs)
> full 2 totalling 208ms (56.1% uptime), avg 104.0ms
> incr 6 totalling 10ms (2.7% uptime), avg 1.7000000000000002ms
> tenures 0
> Allocation of a size -1073741824 ByteArray OK
> uptime 0h0m2s
> memory -1,020,427,928 bytes
> old -1,037,112,380 bytes (101.60000000000001%)
> young 5,952 bytes (0.0%)
> used -1,037,106,428 bytes (101.60000000000001%)
> free 16,678,500 bytes (-1.6%)
> GCs 13 (177ms between GCs)
> full 4 totalling 725ms (31.5% uptime), avg 181.3ms
> incr 9 totalling 14ms (0.6000000000000001% uptime), avg 1.6ms
> tenures 0
> Since last view 5 (386ms between GCs)
> uptime 1.9000000000000001s
> full 2 totalling 517ms (26.8% uptime), avg 258.5ms
> incr 3 totalling 4ms (0.2% uptime), avg 1.3ms
> tenures 0
>
> Basically it seems to work.
>
> What I find particulary strange is that #vmStatisticsReportString starts reporting negative sizes, also the size of the 1GB ByteArray is reported as negative. Why ?
>
> Tomorrow I might try to find out how much further I can take this ? How close to 4GB ?
>
> Anybody else tried this ?
>
> Sven
>