How to tune Huygens multiprocessing performance?
The Huygens compute engine (CE) uses the OpenMP standard for multiprocessing. The multiprocessing behavior of the CE can controlled with OpenMP environment variables or from the Huygens-Tcl layer.
Environment variables:
- The number of threads to be used is controlled through OMP_NUM_THREADS, for example: 'setenv OMP_NUM_THREADS 2'
- Allow the operating system to dynamically adjust the number of threads depending on system load: OMP_DYNAMIC (TRUE, FALSE), for example 'setenv OMP_DYNAMIC TRUE'. If OMP_NUM_THREADS is set then the number of threads varies between 1 and OMP_NUM_THREADS.
Huygens-Tcl layer:
huOpt cpu ?-min <integer>? ?-max <integer>? ?-mode <compliant|ignore>? ?-query <system|min|max|mode>
This allows setting of the minimum and maximum to the number of threads. Mode compliant is equal to OMP_DYNAMIC TRUE. With
-mode ignore the CE tries to always use the max thread number. With the -query mode the curent state can be queried.Example:
huOpt cpu -max 4 -mode ignore to run on four threads regardless of system load.Keywords: multiprocessing environment OpenMP huOpt<br>
Categories: Faq Installation, Faq Platforms, Faq Miscellaneous, Huygens Faq, Imported Faqs<br>
Platforms: Irix AIX<br>
Related products: Hu Ess Hu Pro Hu Script FluVR<br>
