Logged In: YES 
user_id=44345

Here's a new version that includes Jeremy's shortcut.  With 
_Py_CheckInterval initialized to 10 here are the pystones numbers I get:

with my initial patch & Jeremy's ticker shortcut:

Pystone(1.1) time for 50000 passes = 7.67
This machine benchmarks at 6518.9 pystones/second
Pystone(1.1) time for 50000 passes = 7.67
This machine benchmarks at 6518.9 pystones/second
Pystone(1.1) time for 50000 passes = 7.65
This machine benchmarks at 6535.95 pystones/second


back to just my initial patch without the shortcut:

Pystone(1.1) time for 50000 passes = 7.59
This machine benchmarks at 6587.62 pystones/second
Pystone(1.1) time for 50000 passes = 7.56
This machine benchmarks at 6613.76 pystones/second
Pystone(1.1) time for 50000 passes = 7.56
This machine benchmarks at 6613.76 pystones/second

I'm perplexed by the performance difference.  Again, I think these 
performance numbers should be checked by some other people.  BTW, I 
configured with

    OPT=-O3 ../configure

in my build directory.  I'm using gcc 2.96 and glibc 2.2.4.