When a laptop goes into sleep mode, operating system tries to conserve power by stopping most processes and putting computer in a low-power state. However, sometimes a process may continue to run or periodically wake up computer, preventing it from entering a deep sleep state. This can lead to increased power consumption and a shorter battery life. In this article, we'll explore how to investigate which process is causing wakeups during laptop sleep-mode in MacOS or Linux. Understanding Power Management Subsystem Before we dive into how to investigate sleep mode wakeups, it's important to understand power management subsystem in your ... Read More

Introduction In world of computer programming, an ELF (Executable and Linkable Format) file is a binary file format used in Unix-based operating systems such as Linux, FreeBSD, and Solaris. These files contain executable code and data, which are used to launch programs and libraries. In some cases, however, ELF files may contain many zero bytes. In this article, we will explore why ELF files may contain many zero bytes, their impact on programs, and how to fix this issue. Why ELF files contain many zero bytes? An ELF file consists of a header followed by sections containing executable code, data, ... Read More

Introduction Linux is an open-source operating system that is popular among developers and system administrators. It is known for its flexibility, reliability, and security features. One of features that make Linux stand out from other operating systems is its ability to interact with various hardware components seamlessly. In this article, we will discuss whether Linux emits events when a monitor is connected with a D-sub connector. We will explore various methods that can be used to detect and manage connection of monitors to Linux-based systems. What is D-sub connector? Before we dive into details of how Linux interacts with monitors ... Read More

Introduction Java Native Access (JNA) is a Java library that provides an interface for accessing native code from Java programs. It enables developers to use functionality of native libraries or applications without need to write native code or deal with complexity of C or C++ programming languages. On other hand, process execution refers to creation of new processes in operating system. In this article, we will discuss advantages of using JNA over process execution, along with some examples. Improved Performance One of main advantages of using JNA over process execution is improved performance. When using process execution, a new process ... Read More

Introduction When working with ARM-based Linux systems, one of critical functions that programmers often need to use is mprotect. This function is used to protect specific areas of memory from unauthorized access, modifying or executing. However, one of common questions asked by developers is whether mprotect flushes instruction cache on ARM Linux. In this article, we will explore concept of mprotect and its impact on instruction cache on ARM Linux. We will also discuss some examples and scenarios that can help you understand function better. What is mprotect? Mprotect is a function that allows programmers to modify memory protection settings ... Read More

Introduction Linux is an open-source operating system that is popular among users and developers because of its flexibility and security. One of features that makes Linux stand out from other operating systems is its per-process resource limits. These limits ensure that a process does not use more resources than necessary and cause other processes to slow down or fail. However, setting and managing these resource limits can be a challenging task, especially for those who are new to Linux operating system. In this article, we will take a closer look at per-process resource limits in Linux and how to set ... Read More

Introduction Kernel-based Virtual Machine (KVM) is a virtualization infrastructure for Linux that allows multiple operating systems to run simultaneously on a single host machine. It is a popular open-source virtualization technology that leverages hardware virtualization support, such as Intel VT-x and AMD-V, to run multiple virtual machines on same physical hardware. KVM has a modular architecture, with different components responsible for different aspects of virtualization. In this article, we will explore entry of hypercalls in KVM. Hypercalls in KVM A hypercall is a privileged instruction that allows a virtual machine to interact with hypervisor, which is software layer that controls ... Read More

Introduction The architecture of ARM processor has become increasingly popular in embedded systems and mobile devices due to its low power consumption, high performance, and low cost. It is widely used in development of operating systems such as Windows CE and Linux. In this article, we will be discussing ARM calling conventions on Windows CE and Linux. What is a Calling Convention? A calling convention is a set of rules that dictate how function calls are made in a program. These rules are used to define how arguments are passed, how return value is handled, and how stack is managed ... Read More

Multi Pointer X (MPX) support is a feature of X Window System that enables multiple users to interact with a single computer at same time, each with their own keyboard and mouse. This is useful in situations where several people need to work on a single computer simultaneously, such as in collaborative environments or for teaching purposes. In this article, we will explore features and benefits of MPX support, as well as some examples of how it can be used. What is Multi Pointer X (MPX) Support? The X Window System is a popular windowing system used on Unix-like operating ... Read More

Introduction Subdomains are a great way to divide your website into different sections, making it easier for visitors to navigate and find what they’re looking for. But what if you need to create multiple levels of subdomains, such as blog.example.com or shop.blog.example.com? This can seem daunting, but with Apache2 and/or PHP, it’s actually quite simple. In this article, we’ll walk you through steps of creating multiple level subdomains with examples and sub-headings. What are subdomains? Subdomains are a way of creating a separate section of your website that has its own unique URL. For example, instead of having all of ... Read More