[plt-scheme] Appalling performance of DrScheme on Windows

From: Jepri (jepri at alphacomplex.org)
Date: Mon Jun 19 23:47:33 EDT 2006

Matthias Felleisen wrote:

> This sounds indeed like an appalling response time and it makes me 
> wonder why some 10,000 people are using DrScheme on Windows. Now I am 
> using DrScheme on Windows XP only via Virtual PC on a Mac OS X laptop 
> and it runs very nicely there. On my Mac, I am running "large" 
> programs (up to 5,000 lines, threaded) in DrScheme, leave the 
> environment open for days and weeks at a time, and haver very few 
> problems of this kind.

Users will often silently tolerate some suprisingly bad program 
behaviour if they like the program enough.  When asked why they didn't 
report the problem they just shrug.

e.g. PLT Scheme often locks up my WinXP laptop for a short while when I 
use it after my laptop recovers from hibernation.  CPU use goes to 100, 
the disc starts chittering and all windows owned by DrScheme and 
MzScheme stop responding.  This has continued since 299 on three 
laptops.  I didn't report it because I couldn't reliably reproduce it 
and I don't know how to inspect a windows system like I can on Unix.

machines:  3.2 Ghz Pentium w/ 1.25 Gb RAM, 1.5Ghz Pentium w/ 756 Mb RAM, 
1.8 Ghz Celeron w/ 1.5Gb RAM.

This is most definately not just windows paging out - I am able to 
switch away and bring Mozilla out of the page file while DrScheme is 
twitching in the background.  It can continue for over a minute and 
appears to take longer the more memory windows shows allocated to DrScheme.

After about 3 days of this behaviour DrScheme will lock up completely 
with the above symptoms.

Using the windows task killer on DrScheme results in a more intense disc 
thrash for about 30 secs before the process finally quits.

> But before we bash Microsoft one more time on this list, let's 
> investigate your report in some detail. We don't want to blame them 
> for nothing, right?
> 1. What kind of machine do you own? CPU speed and memory are two 
> things we'd really like to know.
> 2. Which PLT Scheme implementation are you running? 350? 103p1? 
> Anything in between?
> 2a. Have you modified your PLT Scheme installation in any form or manner?
> 3. What kind of programs do you run? Are they text-book exercises? 
> Dynamic flow equations?
> Once we have that information we will figure out how to get you to use 
> this thing in an acceptable manner.
> Thanks for the report -- Matthias
> On Jun 19, 2006, at 6:31 PM, wooks wooks wrote:
>> I am running DrScheme on Windows XP and I regularly experience 
>> abysmal response time running DrScheme.
>> Usually its starts off ok but the longer its left running the worse 
>> the response time gets (especially if you leave a session idle for a 
>> long time). It is not uncommon for me to manage only 4 interactions 
>> in an hour because DrScheme just hangs for ages before it will accept 
>> input.
>> Previously I had the same problem running under Win2k. I thought it 
>> would go away when I bought a new machine last year runnnig windows 
>> XP but its just as bad.
>> It is pretty much impossible to use the environment with this sort of 
>> response time.
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