Squeak and parallel computation

Alan Kay Alan.Kay at squeakland.org
Tue Oct 8 16:35:32 UTC 2002


The "Tea" collaboration stuff that Dave Smith, Dave Reed, and Andreas 
Raab (with yrs truly as minor kibitzer) have been working on over the 
last year will be released as gamma open source within the next week 
or two. Besides some really nice immersive sharable 3D environment 
stuff, there is a coordination system for dealing with many 
processors (right now this means many separate machines collabing on 
one logical parallel computation of many processes -- but the 
semantics also does the separation of meanings that are required to 
allow parallel computation on one machine with multiple processors).

Cheers,

Alan

-----

At 5:18 PM +0200 10/8/02, Bert Freudenberg wrote:
>On Tue, 8 Oct 2002, Ian Piumarta wrote:
>
>>  On Mon, 7 Oct 2002, Aaron J Reichow wrote:
>>  > On Tue, 8 Oct 2002, Ian Piumarta wrote:
>>  > > if your VM runs on one processor and your X server on another then
>>  > > you should see an improvement for graphics-bound code.
>>
>>  I can get the ratio to 5:1 Squeak:X by scrolling a large window of text.
>>
>>  Every time Squeak does screen (or keyboard/mouse) i/o it's fighting with X
>>  server for resources.  One of the "improving performance" hints in the X11
>>  FAQ is to run clients on a different machine, which is the same thing as
>>  "one of your other processors" modulo the network.  (This doesn't work
>>  well for Squeak since it stores the display as a client-side image and the
>>  network bandwith goes through the roof when you try to run it remotely.
>>  OTOH, running it on one of your other processors should yield the same
>>  advantages as running remotely but without any of the disadvantages of
>>  network saturation -- particularly when using shared memory to send the
>>  image to the server.)
>>
>>  But I'm only guessing.  Maybe somebody with a SMP machine can testify from
>>  experience.
>
>I'm running on a dual-processor PIII 600MHz here. Scrolling a text window
>utilizes one CPU to almost 100%, X is using the second processor:
>
>bert.balloon ~ > squeak  -xshm -display unix:0  &
>bert.balloon ~ > top
>  PID USER     PRI  NI  SIZE  RSS SHARE LC STAT %CPU %MEM   TIME COMMAND
>2711 bert      11   0 12820  12M  4268  1 R    99.8  5.0   1:11 squeak
>1441 root       9   0  147M  19M  9132  0 S    16.2  7.6   6:25 X
>
>Of cource, doing it without shared memory increases the load for X:
>
>bert.balloon ~ > squeak &             
>bert.balloon ~ > top
>   PID USER     PRI  NI  SIZE  RSS SHARE LC STAT %CPU %MEM   TIME COMMAND
>  2772 bert      14   0 13504  13M  1076  0 R    90.5  5.3   1:15 squeak
>  1441 root      10   0  144M  16M  6080  1 R    33.6  6.4   7:17 X
>
>
>-- Bert


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