Open Source Summit + AI_dev Japan 2024

CXL memory offers the promise of increased memory capacity, which addressing the limitations of conventional DDR DRAM, and also features a memory pool that allows users to dynamically adjust memory allocation based on workload needs. The Linux community has been rapidly developing many CXL features. Additionally, users can try a CXL memory environment with QEMU emulation without actual CXL hardware. This allows users to experiment with CXL memory features in an emulated environment. However, there are some difficulties and considerations when using CXL memory. For example, you cannot use CXL (2.0 or later) memory devices without configuring them using the "cxl create-region" command. Moreover, if you want to utilize memory interleave to achieve optimal performance, you need to understand the hardware topology, including the CXL switch, and reconfigure the region for CXL volatile memory at every boot time. While development is ongoing, these features may be improved in the future. However, there are still many difficulties for users at present. This talk will cover how to use CXL memory and its emulation.