The warning messages are often displayed when you use MLlib in Apache Spark. It means native BLAS implementations are not rightly installed or configured for your Apache Spark. A pure Java implementation is used which could harm the performance.
Recently I have to accelerate my last code and most of time are spent on solving linear sparse systems. Since my coefficient matrix is a symmetric positive definite matrix (s.p.d.), I always use CHOLMOD. But its performance cannot reach my requirement, I tried to search another better solver.
Download, compile and install gotoBLAS2 (NOTE: With new CPU, it may have errors when compiling. We can get solutions by searching the errors information online).