Linux Kernel 6.13 is Released: This is What's New for Compute Express Link (CXL)

How To Map a CXL Endpoint to a CPU Socket in Linux

• Steve Scargall
• Cxl , How to , Linux

When working with CXL Type 3 Memory Expander endpoints, it’s nice to know which CPU Socket owns the root complex for the endpoint. This is very useful for memory tiering solutions where we want to keep the execution of application processes and threads ’local’ to the memory.

CXL memory expanders appear in Linux as memory-only or cpu-less NUMA Nodes. For example, NUMA nodes 2 & 3 do not have any CPUs assigned to them.

Is Thinking Mode Affecting Your Agentic Workflows?

• Steve Scargall
• Ai

I jumped on the trend of running local LLMs and agents and was having a lot of fun until my agents kept failing, timing out, and just stopping without any obvious reason. I tried PaperClip + ZeroClaw, PaperClip + Hermes-Agent, and Hermes-Agent + Hermes-Workspace with Qwen 3.6 and Gemma 4 models (various sizes and quantization levels). All of them failed in the same way at some point in the workflow with almost nothing reported in the logs to indicate what was happening. Some tasks completed without any problem, but most did not, often leaving me to wonder what was going on. After many hours of debugging and reading many forums, I finally found that this was a model serving configuration trap that catches many people the first time they self-host a reasoning model.

CXL Memory NUMA Node Mapping with Sub-NUMA Clustering (SNC) on Linux

• Steve Scargall
• Linux , Cxl

CXL (Compute Express Link) memory devices are revolutionizing server architectures, but they also introduce new NUMA complexity, especially when advanced memory configurations, such as Sub-NUMA Clustering (SNC), are enabled. One of the most confusing issues is the mismatch between NUMA node numbers reported by CXL sysfs attributes and those used by Linux memory management tools.

This blog post walks through a real-world scenario, complete with command outputs and diagrams, to help you understand and resolve the CXL NUMA node mapping issue with SNC enabled.