Introduction In general, if we want to debug Linux Kernel, there are lots of tools such as Linux Perf, Kprobe, BCC, Ktap, etc, and we can also write kernel modules, proc subsystems or system calls for some specific debugging aims. However, if we have to instrument kernel to achieve our goals, usually we would not
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Tag: Programming
QEMU/KVM Network Mechanisms
Posted onIntroduction As we know, network subsystems are important in computer systems since they are I/O systems and need to be optimized with many algorithms and skills. This article will introduce how QEMU/KVM [2] network part works. In order to put everything simple and easy to understand, we will begin with several examples and then understand
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Reference: Special HTML Characters
Posted onHTML supports many characters/symbols such as mathematical symbols, and currency symbols. They are not present on a normal keyboard. And some of these characters may have special meanings for formatting text. To add such characters / symbols to an HTML text, you can use an HTML entity name or an entity number in decimal or
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Basic Knowledge of HTML and Canvas
Posted onFrom a small business owner, a blogger, a student or individual with a personal project, the need to create websites has never been more prominent. Having a basic understanding of HTML and canvas knowledge can be helpful, and it is simple to master. The thought of learning to code and programming may seem a long
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How to Install Paravirtualized CentOS 7 DomU on Xen
Posted onThis post introduces how to install a paravirtualized CentOS 7 DomU on Xen. The very common way of installing DomU does not work for CentOS 7. A little trick to set the repository and the network used by the VM should be used by adding a setting strings to the “extra=” field for this VM.
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Building and Installing Linux Kernel from the Source Code in an Existing Linux OS
Posted onBuilding Linux kernel may sound a complex and geek-only thing. However, as Linux kernel itself has much less depended tools/packages compared to other software packages, it is quite easy to compile, build and install a Linux kernel from the source code in an existing Linux OS. Building Linux kernel is needed if you need to
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How does linux kernel collect task stats data
Posted onMotivation Recently, I find it is hard to know the percentage of time that one process uses to wait for synchronous I/O (eg, read, etc). One way is to use the taskstats API provided by Linux Kernel [1]. However, for this way, the precision may be one problem. With this problem, I dig into Linux
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Are You Wanting to Learn a Programming Language? Read Before Your Make a Choice
Posted onMaking a career choice is difficult. And, if you have decided on becoming a programmer, the difficulty is just beginning. The most important thing is to first decide the language that you want to learn and this is often the most difficult decision. The good part is that you know you need to focus on
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Vim Tutorial for Beginners: vimtutor
Posted onThere are many Vim tutorials and Vim tips on the Web. However, I find the vimtutor provides the best tutorial among those so far as I found on the Web while the vimtutor seems usually reachable from a terminal which is not obviously known to Vim beginners who are usually Linux beginners too. This page
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Spring Shell Technology For Java development
Posted onThis post is about the Spring Shell technology and its use in java. Experts of java development India have shared their best knowledge in this post for Spring Shell with the community people. If you have anything to ask, do it at the end. Technology: It is command line tool for Java applications to interact
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Filter Salutation in Microsoft Dynamics CRM
Posted onIn this tutorial, Microsoft Dynamics CRM India experts will teach you how to filter salutation based on Gender field in MS CRM. You can follow the step-by-step guide shared in this post to avail the results. Description- According to the requirement we need to filter salutation based on gender in contact entity. For this we
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The length of timeslices for processes under CFS process scheduling algorithm in Linux Kernel
Posted onAbstract As is known, CFS (Completely Fair Scheduling) is a famous process scheduling algorithm in Linux Kernel but there is no convenient way for developers to get the timeslices of processes if CFS is chosen. In this article, I will introduce one way to hack the timeslices of process easily for CFS in Linux Kernel.
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How sched_min_granularity_ns, sched_latency_ns and sched_wakeup_granularity_ns in CFS affect the timeslice of processes
Posted onAbstract Currently, the most famous process scheduling algorithm in Linux Kernel is Completely Fair Scheduling (CFS) algorithm. The core idea of CFS is to let each process share the same proportional CPU resources to run so that it is fair to each process. In this article, I will introduce how sched_min_granularity_ns and sched_latency_ns work internal
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Push and Pull data from Restful Service in Asp.net MVC Application using Angular JS
Posted onIn this post, asp.net development India based professionals will explain the best way to manage the Restful service using AngularJS. They are explaining the push and pull functionality available in Rest service in simple steps. Read the article to know more. In this Post I am going explain how we can manage the Restful service
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How sched_setaffinity works inside of Linux Kernel
Posted onAbstract Sometimes, we may want to migrate one process/thread to one specific CPU for some specific purpose. In the Unix/Linux systems, you may choose sched_setaffinity to finish this job. This article will help you to understand how sched_setaffinity (or other APIs like pthread_setaffinity_np in user-space) works internal Linux kernel. Details SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int,
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Parameterised AngularJS Routing in Asp.net MVC using $routeProvider
Posted onIn this post, asp.net development India based professionals will brief you about the interesting feature of AngularJS, that I Routing. You will learn the method to split the single page into multiple views. For more info, read the article. In this article we are going to see one of the most useful feature of AngularJS
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How to Disable and Enable Laptop Keyboard for X.org Server in Linux
Posted onAttaching a USB keyboard to a laptop is common when using a laptop because a normal keyboard may provide a more convenient typing experience. The laptop keyboard is not used in these situations. However, the laptop keyboard may still be touched by accident. In this post, we will discuss how to disable and enable the
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How to Get Bash Script’s Own Path
Posted onBash script may need to get its own path. In normal Bash script, $0 is the path to the script. However, when a script is sourced, such as . a.sh, a.sh‘s $0 does not give a.sh while the caller’s name. How to reliably get a bash script’s own path no matter whether the Bash script
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Three Methods of Executing Commands on Many Nodes in Parallel via SSH on Linux
Posted onIt is common to execute commands on many nodes/hosts via SSH for managing a cluster of Linux servers. On Linux, there are many choices for this task. Generally, to run commands on many nodes, there are two modes: serial mode and parallel mode. In serial mode, the command is executed on the node one by
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Notes for Beginners of Software Development on Linux
Posted onLinux is a great platform for software development targeting servers or backends. In general, working on Linux is very productive. The problem that beginners on Linux face is the the learning curve is steep at the beginning. But believe me, after you get through the initial green steep learning step as in the figure below
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