Linux Kernel 6.14 is Released: This is What's New for Compute Express Link (CXL)

Linux Kernel 6.14 is Released: This is What's New for Compute Express Link (CXL)

The Linux Kernel 6.14 release brings several improvements and additions related to Compute Express Link (CXL) technology.

Here is the detailed list of all commits merged into the 6.14 Kernel for CXL and DAX. This list was generated by the Linux Kernel CXL Feature Tracker .

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Understanding STREAM: Benchmarking Memory Bandwidth for DRAM and CXL

Understanding STREAM: Benchmarking Memory Bandwidth for DRAM and CXL

In today’s Artificial Intelligence (AI), Machine Learning (ML), and high-performance computing (HPC) landscape, memory bandwidth is a critical factor in determining overall system performance. As workloads grow increasingly data-intensive, traditional DRAM-only setups are often insufficient, prompting the rise of new memory expansion technologies like Compute Express Link (CXL). To evaluate memory bandwidth across DRAM and CXL devices, we use a modified industry-standard tool called STREAM.

In this blog, we’ll explore what STREAM is, how it works, why it’s commonly used for benchmarking memory bandwidth, and how a modified version of STREAM can be used to measure performance in heterogeneous memory environments, including DRAM and CXL.

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Is Your Application Really Using Persistent Memory? Here’s How to Tell.

Is Your Application Really Using Persistent Memory? Here’s How to Tell.

Persistent memory (PMEM), especially when accessed via technologies like CXL, promises the best of both worlds: DRAM-like speed with the durability of an SSD. When you set up a filesystem like XFS or EXT4 in FSDAX (File System Direct Access) mode on a PMEM device, you’re paving a superhighway for your applications, allowing them to map files directly into their address space and bypass the kernel’s page cache entirely.

But here’s the crucial question: after all the setup and configuration, how do you prove that your application’s data is physically residing on the PMEM device and not just in regular RAM? I’ve run into this question myself, so I wrote a small Python script to get a definitive answer using SQLite3 as an example application. However, before we proceed with the script, let’s examine how you can verify this manually.

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How To Install and Boot Microsoft Windows Server 2022 from Persistent Memory (or not)

How To Install and Boot Microsoft Windows Server 2022 from Persistent Memory (or not)

In a previous post  I described how to install and boot Fedora Linux using only Persistent Memory, no SSDs are required. For this follow on post, I attempted to install Microsoft Windows Server 2022 onto the persistent memory.

TL;DR - I was able to select the PMem devices as the install disk, but when the installer begins to write data, we get an “Error code: 0xC0000005”. I haven’t found a solution to this problem (yet).

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