[Python-Dev] stack check on Unix: any suggestions?

[Thomas Wouters]

On Thu, Aug 31, 2000 at 10:58:49AM -0500, Guido van Rossum wrote:

>     C() # This tries to get __init__, triggering the recursion

> I get 5788 iterations on Red Hat Linux 6.2 (ulimit -c says 8192; I
> have no idea what units).

That's odd... On BSDI, with a 2Mbyte stacklimit (ulimit -s says 2048) I get
almost as many recursions: 5136. That's very much not what I would expect...
With a stack limit of 8192, I can go as high as 19997 recursions! I wonder
why that is...

Wait a minute... The Linux SEGV isn't stacksize related at all! Observe:

centurion:~ > limit stacksize 8192
centurion:~ > python teststack.py | tail -3
5134
5135
5136
Segmentation fault (core dumped) 

centurion:~ > limit stacksize 65536
centurion:~ > python teststack.py | tail -3
5134
5135
5136
Segmentation fault (core dumped) 

centurion:~ > limit stacksize 2048
centurion:~ > python teststack.py | tail -3
5134
5135
5136
Segmentation fault (core dumped) 

centurion:~ > limit stacksize 128
centurion:~ > python teststack.py | tail -3
Segmentation fault (core dumped) 

centurion:~ > limit stacksize 1024
centurion:~ > python teststack.py | tail -3
2677
2678
26Segmentation fault (core dumped) 

centurion:~ > limit stacksize 1500
centurion:~ > python teststack.py | tail -3
3496
3497
349Segmentation fault (core dumped) 

I don't have time to pursue this, however. I'm trying to get my paid work
finished tomorrow, so that I can finish my *real* work over the weekend:
augassign docs & some autoconf changes :-) 

-- 
Thomas Wouters <thomas@xs4all.net>

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