Over the past year, I have been implementing an automated infrastructure to test the SystemTap project and to collect and analyze the test results. SystemTap is a scripting language for creating instrumentation to observe a live running Linux kernel and user-space applications. The SystemTap language translator produces Linux kernel modules. These modules depend on internal details of the Linux kernel that vary significantly between different versions of Linux.
Continue reading Automating the testing process for SystemTap, Part 1: Test automation with libvirt and Buildbot
In this article, I examine the performance of two virtual machines (VMs) using huge pages in the Linux kernel. One VM is configured to use transparent huge pages (THP), which happens by default. The other is configured to use 1GiB static huge pages (SHP), which requires special configuration on the virtualization host and in the virtual machine definition.
Continue reading Benchmarking transparent versus 1GiB static huge page performance in Linux virtual machines
Multipath TCP (MPTCP) extends traditional TCP to allow reliable end-to-end delivery over multiple simultaneous TCP paths, and is coming as a tech preview on Red Hat Enterprise Linux 8.3. This is the first of two articles for users who want to practice with the new MPTCP functionality on a live system. In this first part, we show you how to enable the protocol in the kernel and let client and server applications use the MPTCP sockets. Then, we run diagnostics on the kernel in a sample test network, where endpoints are using a single subflow.
Continue reading Multipath TCP on Red Hat Enterprise Linux 8.3: From 0 to 1 subflows