[SciPy-dev] segmentation with scipy+icc during test

Stijn De Weirdt stijn.deweirdt@ugent...
Fri Dec 5 11:24:14 CST 2008


hi all,

i hope i can bother the dev list with this, as it's not a real user
problem imho.

i'm trying to compile python+numpy+scipy with intel toolkit (ictce
3.2.0.17, which has icc/ifc 11.0.069 and mkl 10.1.0.015


python 2.4.5 compiles and the make tests works fine
numpy 1.2.1 compiles and the tests are also fine
scipy 0.6.0 compiles, but one of the tests exits with a segmentation
fault. (i also tried 0.7.0b1, but it also gives segfualt, but haven't
verified if it's the same one)

now i'm trying to figure out which test causes the crash and i have some
questions related to that:
a. how can i skip/reorder tests? (just to check if it's an individual
issue or a broader one)
b. the segfault itself: 
python -v -c 'import scipy; scipy.test(level=10,verbosity=100)'
...

bench_random (scipy.fftpack.tests.test_basic.test_fft)
                 Fast Fourier Transform
=================================================
      |    real input     |   complex input    
-------------------------------------------------
 size |  scipy  |  numpy  |  scipy  |  numpy 
-------------------------------------------------
  100 |    0.07 |    0.06Segmentation fault

looking at the code in scipy/fftpack/tests/test_basic.py, it's the
complex part of bench_random that fails.

the basic code that triggers it, is (at least that how i read it)

x= random([size]).astype(cdouble)+random([size]).astype(cdou\
ble)*1j
y = direct_dft(x) ## size < 500
z=fft(x)

with fft loaded from scipy.fftpack (not from numpy)
(i'm sure it segfaults during the fft(x) call, because i added some
print statements to locate the exact code).

when i add some pprint statements to dump the x values that were used
during the segfault and write a small script doing just the above with
those values, it doesn't segfault. 
so doing the exact steps (except from the self.measure) in a separate
script, i'm unable to trigger the segfault, but the tests always fail.

could someone shine some light on why this seems not reproducable
outside the test environment?

many thanks,

stijn

-- 
The system will shutdown in 5 minutes.



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