operating-systems

What is the difference, in a preempt-able Linux kernel, between PREEMPT_VOLUNTARY and PREEMPT_LAZY modes? Are they the same or are they different? Among these two modes of preemption, does one mode ...

I'm running Manjaro with kernel 6.18.33-1 on an Intel i5-14600K (Raptor Lake Refresh, hybrid architecture with P-cores and E-cores). I'm trying to determine whether the Linux scheduler is actually ...

I admit it: I’m an operating system addict. I’ve installed countless operating systems over my life, and I still use many of them. It may seem like a bad idea. It isn’t. I jump between macOS, Linux, Windows, and Chrome OS across many devices, and that’s just on desktop. On phones, my first was a Google Nexus One then a couple pit stops with Nokia Lumia 521 and 620 Windows Phones. Later I went bac…

Moving beyond fork() + exec() Ready to give LWN a try?Since the earliest days of Unix, two of the core process-oriented system calls have been fork(), which creates a child process as a copy of the parent, and exec(), which runs a new program in the place of the current one. In Linux kernels, those system calls are better known as clone() and execve(), but the core functionality remains the same.…

A few weeks after switching from Windows to Linux, I noticed something interesting. The hardware had not changed. The processor was the same. The RAM was the same. The SSD was the same. And yet, the laptop felt noticeably faster. Not necessarily because applications were completing tasks dramatically quicker, but because the entire system felt more responsive. Keyboard input felt immediate. Windo…

I have read the documentation on tmpfs filesystem. This talks about the mount option size which can be used like given below in the file /etc/fstab tmpfs /tmp tmpfs defaults,size=20% 0 0 Please note ...

This is part of our series going through OSTEP book chapters. The OSTEP textbook is freely available at Remzi's website if you like to follow along. This chapter extends the CPU virtualization playbook to memory. It's the same recipe: let the program run directly on the hardware, but interpose at carefully chosen points so the OS retains control. For memory, this happens at every memory access. E…

The Arch Linux release engineering team published the May 2026 install media on May 1, 2026. The new ISO ships with Linux kernel 7.0.3 and is available now from the official download mirrors at archlinux.org. As with every monthly Arch release, this build exists strictly for fresh installations. Existing Arch Linux users have nothing to […] The post Arch Linux 2026.05.01 Install Media Is Out, Pow…

Chapter 13 of OSTEP provides a primer on how and why modern operating systems abstract physical hardware. This is part of our series going through OSTEP book chapters. The OSTEP textbook is freely available at Remzi's website if you like to follow along. Multiprogramming and Time Sharing In the early days of computing, machines didn't provide much of a memory abstraction to users. The operating s…

The FreeBSD Project has announced the release of FreeBSD 15.0-BETA3, the third beta build in the 15.0-RELEASE cycle. The update brings several critical fixes, improved WiFi compatibility, and expanded image availability for VMs, containers, and cloud platforms. FreeBSD 15.0-BETA3 introduces a series of refinements and security updates aimed at improving system stability and hardware support. […] …

The efficiency of Operating Systems (OSes) has always been in the spotlight of systems researchers, ever since the seminal Dijkstra’s THE multiprogramming system in early 60s. But the reason for this obsession is not entirely obvious. While the OS is commonly perceived as a layer between applications and hardware, such a view is somewhat misleading […]