Dynamic Load Balancing (DLB)

DLB is a library devoted to speed up hybrid parallel applications and maximize the utilization of computational resources. More information about this library can be found at the following link: https://pm.bsc.es/dlb.

To enable DLB support for Nanos6, a working DLB installation must be present in your environment. Configuring Nanos6 with DLB support is done through the --with-dlb flag, specifying the root directory of the DLB installation.

After configuring DLB support for Nanos6, its enabling can be controlled at run-time through the dlb.enabled configuration variable. To run Nanos6 with DLB support then, this variable must be set to true (dlb.enabled=true), since by default DLB is disabled.

Once DLB is enabled for Nanos6, OmpSs-2 applications will benefit from dynamic resource sharing automatically. Assuming that DLB has been explicitly enabled at the configuration file, the following example showcases the executions of two applications that share the available CPUs between them:

# Run the first application using 10 CPUs (0, 1, ..., 9)
$ taskset -c 0-9   ./merge-sort.test &

# Run the second application using 10 CPUs (10, 11, ..., 19)
$ taskset -c 10-19 ./cholesky-fact.test &

# Now those applications should be running while sharing resources
# ...