We already know we have to divide an array into two sub-array for quicksort algorithm. Here I’ll describe how this partitioning actually works. If you want to know about how quicksort works, follow my other post on quicksort working principle. I followed Introduction to Algorithms, 3rd Edition (MIT Press) for writing this tutorial. Continue reading “QuickSort: Partition an Array into Sub-array”
QuickSort is the most elegant sorting algorithm with an average case time complexity of O(nlogn). The main idea behind quick sort is divide and conquer. I’ll try to explain how this divide and conquer strategy works for quick sort. This writing is a gist from Introduction to Algorithms, 3rd Edition (MIT Press), a cool book for algorithm enthusiasts. Continue reading “QuickSort Algorithm Working Principle”
Finding an integer pair with given sum is a very familiar problem in algorithm community. The general problem is: given an array of integer numbers and a given sum, how do we find out a integer pair with given sum? Continue reading “Integer Pair With Given Sum From an Array”
In previous tutorial we learned how to write a basic kernel module for Linux. This tutorial will explain how we can pass parameters to kernel module using command line arguments. This writing is greatly inspired by The Linux Kernel Module Programming Guide, a great book for device driver developers. Continue reading “Pass Parameters To Kernel Module”
This writing will provide an easy to follow, step by step guide to configure a QEMU Bridge Network in Ubuntu 14.04 host machine. Though I’ve done it in Ubuntu 14.04 machine, I believe it’ll also work on Ubuntu 12.04.
By default, QEMU VM uses user networking which allows the VM to Continue reading “Configure QEMU Bridge Network in Ubuntu 14.04”
People follow many approaches to detect loop in linked list. Here I’m going to discuss about two approaches. Both approaches can be used on a singly linked list or doubly linked list. Continue reading “Detect Loop in Linked List”
Linux Kernel hast three memory allocator named SLOB, SLAB and SLUB. SLOB allocator is the memory allocator that is used to allocate small amount of memory for Linux kernel objects. Linux kernel objects are different from user mode objects. So we can’t use a user mode application for testing SLOB allocator. For example, if we modify the algorithm used in SLOB allocator, we have to test it using some kernel module which can make memory request to our new SLOB allocator. Continue reading “Testing Slob Allocator”
Writing Linux kernel module is a daunting task. This easy to follow, step by step guide will show us all the steps of writing Linux kernel module. Read this writing to learn about what is a kernel module.
This tutorial will be our starting point for writing Linux kernel module. For this one we won’t be using any real hardware. But gradually we’ll learn how to write a device driver for an actual hardware. Our approach will start from learning most basic module to advanced device driver. Continue reading “Writing Linux Kernel Module”
Kernel module is a piece of program which can be loaded or unloaded in the kernel dynamically. It is used to extend the functionality of the kernel without rebooting the system. When we attach a new hardware in our computer we have to install a device driver for it. Device driver is a kernel module which allows the kernel to communicate with the hardware device. Continue reading “Linux Kernel Module”