[Pkg-exppsy-maintainers] Segfault example

[Yaroslav Halchenko]

Sorry I didn't follow up -- I did run and reproduced -- it puked many times and
at the end with (which is I think what you got also). I was going to debug it a
bit more but yet had a chance... will do later...  From Michael we should get
versions of involved packages (numpy, blas, lapack) to see what makes the
difference... Also - I ran it on i386 box...  what did you run it on?

==10429== Invalid read of size 4
==10429==    at 0x503DD6D: ATL_dcopy_xp1yp1aXbX (in /usr/lib/atlas/libblas.so.3.0)
==10429==  Address 0x5A8B5A0 is 8 bytes after a block of size 880,000 alloc'd
==10429==    at 0x40244B0: malloc (vg_replace_malloc.c:149)
==10429==    by 0x470FCA0: (within /usr/lib/python2.4/site-packages/numpy/core/multiarray.so)
==10429==    by 0x4711EF3: (within /usr/lib/python2.4/site-packages/numpy/core/multiarray.so)
==10429==    by 0x4712071: (within /usr/lib/python2.4/site-packages/numpy/core/multiarray.so)
==10429==    by 0x80B9C49: PyEval_EvalFrame (in /usr/bin/python2.4)
==10429==    by 0x80BB0E4: PyEval_EvalCodeEx (in /usr/bin/python2.4)
==10429==    by 0x80B9319: PyEval_EvalFrame (in /usr/bin/python2.4)
==10429==    by 0x80B99C3: PyEval_EvalFrame (in /usr/bin/python2.4)
==10429==    by 0x80B99C3: PyEval_EvalFrame (in /usr/bin/python2.4)
==10429==    by 0x80BB0E4: PyEval_EvalCodeEx (in /usr/bin/python2.4)
==10429==    by 0x80BB156: PyEval_EvalCode (in /usr/bin/python2.4)
==10429==    by 0x80DDF79: PyRun_FileExFlags (in /usr/bin/python2.4)
--10429-- VALGRIND INTERNAL ERROR: Valgrind received a signal 11 (SIGSEGV) - exiting
--10429-- si_code=1;  Faulting address: 0x4;  sp: 0x6250EDBC

valgrind: the 'impossible' happened:
   Killed by fatal signal
==10429==    at 0x3801FFEA: unlinkBlock (m_mallocfree.c:314)
==10429==    by 0x380208A0: vgPlain_arena_free (m_mallocfree.c:1162)
==10429==    by 0x38036501: vgPlain_cli_free (replacemalloc_core.c:108)
==10429==    by 0x38001A1B: die_and_free_mem (mc_malloc_wrappers.c:111)
==10429==    by 0x38036C82: do_client_request (scheduler.c:1158)
==10429==    by 0x380385A0: vgPlain_scheduler (scheduler.c:869)
==10429==    by 0x38058946: run_a_thread_NORETURN (syswrap-linux.c:87)

sched status:
  running_tid=1

Thread 1: status = VgTs_Runnable
==10429==    at 0x40240CA: free (vg_replace_malloc.c:233)
==10429==    by 0x505495E: ATL_dmmJIK (in /usr/lib/atlas/libblas.so.3.0)



On Wed, 16 Jan 2008, Per B. Sederberg wrote:

> Hi Yarik:

> Did you have the chance to run the ridge regression example code that
> is breaking on my machine?  Michael ran it on his machine and could
> not reproduce the error.

> This is getting quite weird and I'm not sure where to go from here.
> It breaks at the same point (returning from the _train call) for all
> of my actual data.  The call to the numpy.linalg.lstsqr runs with no
> error and returns the correct values while inside the _train call, but
> all goes haywire upon the return from that method when the python
> garbage collection kicks in.

> Any thoughts on how to proceed are more than welcome from all.

> Thanks,
> Per


-- 
Yaroslav Halchenko
Research Assistant, Psychology Department, Rutgers-Newark
Student  Ph.D. @ CS Dept. NJIT
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