Alan Kay Alan.Kay at squeakland.org
Thu Apr 3 21:25:08 UTC 2003

Thanks Tim --

Getting to the bottom of this would be really great!



----At 12:25 PM -0800 4/3/03, Tim Rowledge wrote:
>Aaron J Reichow <reic0024 at d.umn.edu> wrote:
>>  The Dynapad R0.1 image is based on Squeak 2.8, while TinySqueak is
>>  based on 3.0.  While not the source of all of the speed difference, a lot
>>  of it is likely because of the differences between 2.8 and 3.0.  There has
>>  been some talk on this list about the generally change in responsiveness
>>  between Squeak version 2.8 and 3.0.  Some people seem to think that this
>>  is absurd, but a lot of people have noticed that there is indeed a
>>  difference in how fast Squeak feels that occured somewhere in the series
>>  from 2.8 to 3.0.
>I just ran up a 2.8 image on my Acorn and it is waaaay more responsive
>than any recent image. This is, I think, largely due to it being an MVC
>based image from _before_ the event system was put in. The Controllers
>are rapidly polling for any input rather than waiting on a semaphore. I
>can get similar response from a modern image in an MVC project _IF_ I
>change the global sensor to an instance of InputSensor instead of
>EventSensor. It crashes if you go to a morphic project though. :-(
>Funnily enough if I do '0 tinyBenchmarks' in that 2.8 image I get.....
>258 bc/sec and 496 sends/sec :-) something is a little wrong there.
>Even odder, if I try to run a 2.9 or 3.0 image on my current VMs they
>simply don't work; the 3.0 never opens a display, the 2.9 takes in
>excess of 5 minutes to draw the screen. With the 2.9 vm instead, the 2.9
>image starts up ok but takes no notice of the mouse! Funny, it used to
>work just fine.
>The key to improving things is Profiling. Last time we had a small blitz
>on morphic performance some real improvements were made. It would be
>great if somebody with a bit of time could make some good test cases for
>as many UI operations as possible. I'd start with
>opening a browser and setting to a particular method (Andreas provided
>a recipe for that)
>opening a menu (several sizes would be good, include prebuilt and JIT
>scrolling a text view
>entering text (various cases including into an empty view, in the middle
>of a small paragraph and a large paragraph etc)
>popping up/removing a flapping scrollbar
>selecting an item from a list
>If we could have a SUnit suite for these then at least we could run them
>after any suggested UI related changes and see if they have had any bad
>effects (or good ones)
>Tim Rowledge, tim at sumeru.stanford.edu, http://sumeru.stanford.edu/tim
>"E=Mc^5...nahhh...E=Mc^4...nahh...E=Mc^3...ah, the hell with it."


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