About OMP_NUM_THREADS？

[zhuyidong-YP]

When i set 'unset OMP_NUM_THREADS',
running pddrive example with big.rua, FACTOR time is 13s, Mflops value is 0.67.

But set 'export OMP_NUM_THREADS=1', in the same way,
FACTOR time is 0.005s, Mflops value is 1780.63.

What could be the reason？
It's not necessarily a problem.I don't know, nobody else has had the same problem.

[zhuyidong-YP]

[xiaoyeli]

Before you set any environment variable related to OpenMP, can you do this:
$ echo $OMP_NUM_THREADS ?
I suspect it's a large number.

[zhuyidong-YP]

Before you set any environment variable related to OpenMP, can you do this: $ echo $OMP_NUM_THREADS ? I suspect it's a large number.

This is cpu info:

When i run 'export OMP_NUM_THREADS=62 && ./pddrive big.rua', the FACTOR time is 10.5s, and Mflops is 0.8.
Run 'export OMP_NUM_THREADS=60 && ./pddrive big.rua', the FACTOR time is 0.137s, and Mflops is 61.01.

[zhuyidong-YP]

Before you set any environment variable related to OpenMP, can you do this: $ echo $OMP_NUM_THREADS ? I suspect it's a large number.

Compare data with pardiso:

[zhuyidong-YP]

Before you set any environment variable related to OpenMP, can you do this: $ echo $OMP_NUM_THREADS ? I suspect it's a large number.

Currently, we use superlu_dist-8.1.0.tar.gz package. Could it have been fixed in last version, i will try v8.1.2 tags?

[xiaoyeli]

Are you able to resolve the issue? It is very abnormal that when you increase OMP threads from 1 to 2, the runtime is more than doubled.