In the inventory, some variables are used to manage the RT (see Cluster installation section).

Interrupt Requests

The irqmask define the environment variable IRQBALANCE_BANNED_CPUS. It sould ignore some CPU and never assign interrupts (more details here, the irqbalance manual).

The workqueuemask is his negation. There are no function to get it because the project want avoid maintain an algorithm. It's used to configure the kernel.

These variables is a hex mask without "0x" where the first CPU is the least signifiant bit.

Kernel configuration

The cluster is installed with a real-time kernel on each node. It must execute orders without delay. So, some CPUs should be isolated from the scheduler kernel with isolcpus kernel parameter.

• To specify some CPU:

isolcpus=<cpu number>,...,<cpu number>

• To specify a range of CPU is:

isolcpus=<cpu number>-<cpu number>

We can merge these syntax to specify some CPU and ranges of CPUs.