SysTutorials

Call Forwarding for iPhone: How to Set up or Disable Call Forwarding in iOS

By David Yang,
Call forwarding is useful if you are expected to be unavailable for receiving calls or lose cell phone coverage for some time. Call forwarding is not something that is "new" to modern phones. It is a feature which is invented in 1960s (the patent expired in 1980) of some telephone switching systems. But with iPhone/iOS, there is a convenient call forwarding feature in iOS for you to set up call forwarding to forward calls to a landline or other phone by its number or disable the call forwarding. » Read more

Reference: Special HTML Characters

By David Yang,
HTML 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 hexadecimal. This post list many special Characters in HTML as a friendly reference. » Read more

Basic Knowledge of HTML and Canvas

By Colin,
From 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 and daunting task, but some people may be surprised to know that it need not be as scary as it sounds. » Read more

How to Install Paravirtualized CentOS 7 DomU on Xen

By Eric Z Ma,
This 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. To install the DomU VM, first download the pxeboot images from CentOS’s official website at http://mirror.centos.org/centos/7/os/x86_64/images/pxeboot/. » Read more

How to Compile and Install Linux Kernel from the Source Code in an Existing Linux OS

By Eric Z Ma,
Building 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 build a specific Linux kernel or update your drivers for a kernel by yourself. » Read more

Make Better Decisions for Your Businesses with Data Visualization

By Joseph Macwan,
Header In today’s time, data visualization has become a significant part of the success story of an organization. With the help of right techniques, visualizing data can reveal insights which the management staff can use in their decision-making in order to make sound data-driven decisions. Mapping software is among the robust data visualization tools that you can avail today. With maps, you can find stories, trends, and insights that cannot be found in spreadsheets. » Read more

How does linux kernel collect task stats data

By Weiwei Jia,
Motivation ∞ 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 Kernel source codes to see how “blkio_delay_total” (Delay time waiting for synchronous block I/O to complete) is calculated. » Read more

Are You Wanting to Learn a Programming Language? Read Before Your Make a Choice

By Joseph Macwan,
Programming LanguagesMaking 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 learning programming and the bad part is that you might still be thinking which programming language should you begin to learn. » Read more

Vim Tutorial for Beginners: vimtutor

By Eric Z Ma,
There 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 shows the content of the Vim tutorial from the command vimtutor in a web page which is especially easier for Vim beginners to get and learn. » Read more

Spring Shell Technology For Java development

By Johnnymorgan,
This 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 with java applications using spring shell framework. » Read more

x-data-plane feature in QEMU/KVM

By Weiwei Jia,
Abstract In systems, sometimes, we use one global lock to keep synchronization among different threads. This principle also happens in QEMU/KVM (http://wiki.qemu.org/Main_Page) system. However, this may cause lock contention problem. The performance/scalability of whole system will be decreased. In order to solve this problem in QEMU/KVM, x-data-plane feature is designed/implemented, which the high-level idea is “I/O requests are handled by dedicated IOThread rather than QEMU main loop threads so that it will not have lock contention among I/O threads and other QEMU main loop threads”. » Read more

Filter Salutation in Microsoft Dynamics CRM

By Ethan Millar,
CRM
In 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 need to create two new field having Datatype(option set). » Read more

Dynamics CRM Consultants Explain How To Filter Sub Branch Lookup Field Value in CRM

By jameswarner,
In this blog Dynamics CRM consultants are sharing a step-by-step guide to explain how to filter another lookup field value based on one Lookup field value. In this Lead entity, they are having two fields Branch and Sub Branch and you will learn how they filter Subbranch based on Branch field. Based on one Lookup field value, how to filter another lookup field value. » Read more

The length of timeslices for processes under CFS process scheduling algorithm in Linux Kernel

By Weiwei Jia,
Abstract 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. Note that, the way introduced following is under Linux Kernel 3.16.39. » Read more

How to convert Managed Solution into Unmanaged for On-Premise CRM organisation?

By jameswarner,
Solution is very important part of Dynamics CRM. In order to deploy your customization, solution is the only bridge which help you to achieve your goal. There are two types of solutions available in CRM: Managed and Unmanaged. Managed Solutions: This is the solutions that you can import and publish only. You neither export it nor you can make any changes in it. » Read more

How sched_min_granularity_ns, sched_latency_ns and sched_wakeup_granularity_ns in CFS affect the timeslice of processes

By Weiwei Jia,
Abstract 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 CFS to affect the timeslice of processes. » Read more

Push and Pull data from Restful Service in Asp.net MVC Application using Angular JS

By jameswarner,
In 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 using AngularJS. Push and Pull functionality of Rest service Json data in MVC View in easy steps. » Read more

How migration thread works inside of Linux Kernel

By Weiwei Jia,
Abstract In computer systems, resources have to be balanced so that the performance will be better based on the same hardware. In Linux Kernel system, we will see some migration kernel threads running as daemons to do this kind of jobs as follows. In this article, we will discuss how Linux Kernel balances its hardware/software resources (NOTE: this article is based on Linux Kernel 4.7 and other versions may have some differences). » Read more

How sched_setaffinity works inside of Linux Kernel

By Weiwei Jia,
Abstract 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 -- sched_setaffinity(pid_t pid, const struct cpumask *in_mask) --- __set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask, bool check) ---- stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg) ----- migration_cpu_stop(void *data) ------ __migrate_task(struct rq *rq, struct task_struct *p, int dest_cpu) ------- move_queued_task(struct rq *rq, struct task_struct *p, int new_cpu) -------- enqueue_task(struct rq *rq, struct task_struct *p, int flags) --------- returns the new run queue of destination CPU Above character steps give a workflow of how sched_setaffinity works (how it migrates one process/thread from the run queue of source CPU to the run queue of destination CPU). » Read more