> >/ I get a segmentation fault upon running the following: > />/ > />/ import numpy > />/ A = numpy.ones((7000000, 8)) > />/ Q, R = numpy.linalg.qr(A) > />/ > />/ on Python 2.7.3, Linux 64-bit using numpy 1.9.0.dev-ec3603f linked > />/ against OpenBLAS. If A is a smaller matrix then the QR decomposition > />/ works (for example A has shape (4000000, 8)). I haven't quite narrowed > />/ down the exact threshold where the crash occurs, however I know that the > />/ above A is 448 MB (Q and R are no bigger), and the machine in question > />/ has 32GB of RAM. I also tested scipy.linalg.qr (version > />/ 0.14.0.dev-ced994c) with the same results. > />/ > />/ I don't get the same problem on my laptop which is Python 2.7.3, Linux > />/ 64-bit but with numpy 1.8.0rc1 linked to OpenBLAS. Both machines have > />/ OpenBLAS 0.2.6. Does anyone have some insight into why this problem is > />/ occuring? > />/ > />/ > /Works fine here with '1.9.0.dev-7457f15' linked against ATLAS. I suspect > problem is in OpenBLAS. What architecture/os do the two machines have? Is > OpenBLAS using more than one core?
Thanks for testing the code. On the desktop machine I am using Debian GNU/Linux 7.2 (wheezy) compiled for x86-64 (Intel(R) Xeon(R) CPU E5-1620), and on my laptop I use Ubuntu 13.04 for x86-64 (Intel(R) Core(TM) i7-3740QM). I tried: export OPENBLAS_NUM_THREADS=1 and export OPENBLAS_NUM_THREADS=1 with the same results (a segfault). Charanpal
_______________________________________________ NumPy-Discussion mailing list [email protected] http://mail.scipy.org/mailman/listinfo/numpy-discussion
