Running under Linux Ubuntu 18.04 with standard/default BLAS library I observe normal behavior. If I install a parallelized BLAS library such as MKL or openblas, any simple matrix operation causes the machine to shut down and reboot immediately. Behavior occurs on a System76 Thelio desktop with Intel i9 9900K processor, and confirmed observed by System76's own technicians. Behavior does not occur on comparable AMD processor in the same machine.
To reproduce from a fresh ubuntu 18.04 install: If I install python3, numpy, and MKL (e.g. following http://dirk.eddelbuettel.com/blog/2018/04/15/) and try some parallel matrix algebra, e.g. on Python following http://hduongtrong.github.io/2016/03/07/Matrix-Multiplication-Benchmark/, the machine crashes/reboots. Identical behavior occurs doing the an parallel matrix algebra in R, so is not software-specific.
As best as I can tell, this seems to be due to the Intel i9 9900K itself when running parallelized BLAS (including but not limited to MKL), but I am unsure how to properly document and report this issue. Any suggestions would be appreciated.
>>"...how to properly document and report this issue...."
<< Could you prepare the standalone case which everyone may compile and check the problem on his side? This is the easiest way to check and then escalate the problem against performance libraries.
@Gennady Thanks, for the reply! I think I wasn't clear that I am reporting a problem that appears to be hardware specific. I have only gotten this behavior on the Intel i9 9900K. I have run the identical code on a fair number of other Intel CPUs (a variety of Intel Xeons, some older i7s) and they do not reproduce this issue. Techs at the manufacturer, https://system76.com, have observed the same behavior on another i9 9900K. So I'm hoping someone with the identical i9 processor or at least something very similar can test this. Given that the error also occurs when using parallel openblas, perhaps MKL is not the ideal forum to report, but I could not find a developer forum for reporting issues with specific intel processors so this seemed like a good place to start.
Here's some minimal python code (based on the link provided above) which I believe will replicate the crash/reboot behavior I observe on an i9 9900K processor that has MKL libraries installed (but does not cause any problems when run on default, non-parallel blas libraries in Ubuntu 18.04):
import numpy as np np.random.seed(1) n = 30000 x = np.array(np.random.randn(n,n), dtype = np.float32) x.dot(x)
Thanks, I tested with the latest version, intel-mkl-64bit-2019.4-070 and also confirmed by installing intel-mkl-64bit-2018.2-046 (installed from apt-get), this behavior occurs in both cases.