Cooperative memory management setup

Red Hat Enterprise Linux 9.2 z/VM guest

Cooperative memory management (CMM, or "cmm1") can reduce the memory that is available to an instance of Linux® on z/VM.

CMM allocates pages to page pools that are not available to Linux. A diagnose code indicates to z/VM that the pages in the page pools are out of use. z/VM can then immediately reuse these pages for other z/VM guests.

To set up CMM, you must perform these tasks:
  1. Load the cmm module.
  2. Set up a resource management tool that controls the page pool. This tool can be the z/VM resource monitor (VMRM) or a third-party systems management tool.

You can also use the cpuplugd command to define rules for cmm behavior.

For information about setting up the external resource manager, see the chapter on VMRM in z/VM: Performance, SC24-6301.