libmem-release/README.md

Overview

Libmem is a C library for managing the state of memory blocks in a Linux system. This library provides a user or orchestration application the ability to online / offline individual memory blocks of the system or specific blocks within a CXL region.

The library consists of a libmem.h header file and a libmem.a library archive. The library also builds a CLI tool mem that allows the user user to view and manipulate the state of system memory blocks from the command line.

Dependencies

To compile, the library requires the following libraries to be installed in addition to typical packages to build C programs (e.g. make)

daxctl uuid cxl

The uuid library can be installed from the system package manager:

apt install uuid-dev

The daxctl and libcxl libraries included with current Linux distributions are typically too old to support the features needed. Consequently, the user is required to build the current version of the ndctl project and install the manually built daxctl and cxl libraries.

See ndctl on build and installation instructions.

Build

To build simply type:

make

To install to /usr/local/* locations type:

make install

CLI Usage

The mem CLI tool can be used to display system memory block information:

mem show info 

To display the state of memory blocks in the system:

mem list

To online system memory block 306

mem block online 306 

To offline a system memory block

mem block offline 306

To online memory block 2 of a CXL region:

mem block online 2 region0 

To offline memory block 2 of a CXL region:

mem block offline 2 region0