Kernel architecture

Online reconfiguration provides a way to extend and replace active operating system components. This provides administrators, developers, applications, and the system itself with a way to update code, adapt to changing workloads, pinpoint performance problems, and perform a variety of other tasks while the system is running. With generic support for interposition and hot-swapping, a system allows active components to be wrapped with additional functionality or replaced with different implementations that have the same interfaces. This paper describes support for online reconfiguration in the K42 operating system and our initial experiences using it. It describes four base capabilities that are combined to implement generic support for interposition and hot-swapping. As examples of its utility, the paper describes some performance enhancements that have been achieved with K42’s online reconfiguration mechanisms including adaptive algorithms, common case optimizations, and workload sp...

Abstract- The kernel is a crucial component in the operating system. This paper presents the three main types of kernels used in operating systems and their benefits and drawbacks in the applications. The microkernel, monolithic kernel, and the hybrid kernels are the three major types that have been outlined and their features. Two major operating systems of desktop computers; Windows Vista and Linux have two different kernel subsystems. Their kernels, though having the same architecture have different subsystems have very different features, which the paper has tried to discuss at length. Some of the notable differences include; process scheduling, process management, memory management and synchronization of the kernel.

Dynamic adaptive operating systems are operating systems that are able to provide a high degree of customisability in a flexible, configurable environment to users and applications. This customization can occur during run-time or boot-time, hence enabling ...

The author has granted a nonexclusive license allowing Library and Archives Canada to reproduce, publish, archive, preserve, conserve, communicate to the public by telecommunication or on the Internet, loan, distribute and sell theses worldwide, for commercial or noncommercial purposes, in microform, paper, electronic and/or any other formats. L'auteur a accorde une licence non exclusive permettant a la Bibliothgque et Archives Canada de reproduire, publier, archiver, sauvegarder, conserver, transmettre au public par telecommunication ou par Nntemet, preter, distribuer et vendre des theses partout dans le monde, a des fins commerciales ou autres, sur support microforme, papier, electronique et/ou autres formats. The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. L'auteur conserve la propriete du droit d'auteur et des droits moraux qui protege cette these. Ni la these ni des extraits substantiels de celle-ci ne doivent etre imprimes ou autrement reproduits sans son autorisation. In compliance with the Canadian Privacy Act some supporting forms may have been removed from this thesis. While these forms may be included in the document page count, their removal does not represent any loss of content from the thesis. Conform §ment a la loi canadienne sur la protection de la vie privee, quelques formulaires secondaires ont ete enleves de cette these. Bien que ces formulaires aient inclus dans la pagination, il n'y aura aucun contenu manquant.

Most UNIX operating system (OS) vendors specify that they guarantee binary compatibility, but because there are some things beyond the control of the vendor, this is only a limited guarantee. Normally this guarantee is only valid if certain rules are followed. This paper covers a set of rules, which when followed, greatly enhance the likelihood of an application maintaining binary compatibility.

Supporting hot-swappable components allows components to be replaced even while they may be in active use. This can allow live upgrades to running systems, more adaptable software that can change its behaviour at run-time by swapping components, and a simpler software structure by allowing distinct policy and implementation options to be implemented in separate components (rather than as a single monolithic component) and dynamically swapped as needed. We describe in general the challenges that must be faced to support hot-swapping, then describe our prototype in the K42 operating system and provide some initial results.

K42 is an open-source, Linux-compatible, scalable operating-system kernel that can be used for rapid prototyping of operating-system policies and mechanisms. This paper reviews the structure and design philosophy of K42 and discusses our experiences in developing and using K42 in the open-source environment. K42 is an open-source, Linux**-compatible, scalable operating-system kernel whose implementation is based on advanced programming techniques and incorporates innovative mechanisms and policies.

K42 is an open-source scalable research operating system well suited to support systems research. The primary goals of K42's design that support such research include exibilit y to allow a multitude of policies and implementations to be supported simultaneously, extensibility to allow new policies and implementations to be readily added, and scalability to enable good performance for both small and

Search engines are the most important tools for web data acquisition. Web pages are crawled and indexed by search Engines. Users typically locate useful web pages by querying a search engine. One of the challenges in search engines administration is spam pages which waste search engine resources. These pages by deception of search engine ranking algorithms try to be showed in the first page of results. There are many approaches to web spam pages detection such as measurement of HTML code style similarity, pages linguistic pattern analysis and machine learning algorithm on page content features. One of the famous algorithms has been used in machine learning approach is Support Vector Machine (SVM) classifier. Recently basic structure of SVM has been changed by new extensions to increase robustness and classification accuracy. In this paper we improved accuracy of web spam detection by using two nonlinear kernels into Twin SVM (TSVM) as an improved extension of SVM. The classifier abi...

K42 is an open-source research OS for 64-bit multiprocessor systems, focusing on the PowerPC architecture. It uses an object-oriented design to achieve good performance, scalability, customisability, and maintainability. K42 supports the Linux API and ABI allowing it to use unmodified Linux applications and libraries, and can be deployed by running on an existing installation of Linux. The development process of K42 is intended to share concepts with Linux; many ideas have been transferred between the two projects. K42 implements each system resource (such as an open file or process) as a set of unique object instances, and supports hot-swapping, which allows these objects to be changed on-the-fly. This enables dynamic reconfiguration and adaptability of the system, and when combined with a kernel module loader, supports dynamic update and hot patching of the OS. Examples of this might include dynamically adapting to file access patterns, or replacing insecure code in the network st...

This paper presents the development of a microkernel with a device driver controller for embedded systems. The implementation was done in C language aiming low cost microcontrollers. The proposed system allowed to perform soft real-time activities while keeping the drivers and the application isolated by a secure layer. The callback system proved itself extremely simple to use while still maintaining the security of the system regarding the temporal constraints.

This paper is intended to present the implementation and testing methodology of Transductive Support Vector Machines (TSVM) proposed by Joachims et al., and extended by Li et al. Initially, Support Vector Machines are explained as optimal classifiers, along with the concept of transductive inference. Along the implementation process, several tests were performed. The data used for such tests was very diverse especially with respect to the dimensionality (number of samples, features, etc.). The ultimate objective was the evaluation of the transductive inference tool in the already developed Intelligent Interface Web Engine from the SISTA group at the Catholic University of Leuven (Belgium).

With the advancement in embedded area, importance of real time operating system (RTOS) has been increased to greater extent. Now days for every embedded application low latency, efficient memory utilization and effective scheduling techniques are the basic requirements. Thus, in this paper we have attempted to compare some of the real time operating systems.

This paper is intended to present the implementation and testing methodology of Transductive Support Vector Machines (TSVM) proposed by Joachims et al., and extended by Li et al. Initially, Support Vector Machines are explained as optimal classifiers, along with the concept of transductive inference. Along the implementation process, several tests were performed. The data used for such tests was very diverse especially with respect to the dimensionality (number of samples, features, etc.). The ultimate objective was the evaluation of the transductive inference tool in the already developed Intelligent Interface Web Engine from the SISTA group at the Catholic University of Leuven (Belgium).

Embedded System (Sistem Tertanam) adalah suatu sistem komputer yang didesain untuk menangani pekerjaan atau tujuan spesifik. Secara garis besar mirip dengan Operating System yang ada pada PC. Real-Time Operating System (RTOS) adalah sistem operasi yang multitasking yang ditujukan untuk aplikasi yang real time. RTOS juga dapat diartikan sebagai Program yang menjadwalkan semua eksekusi atau pekerjaan yang sangat teratur, mengatur semua resource dari sistem, dan menyediakan dasar yang konsisten untuk mengembangkan kode aplikasi diatasnya. RTOS (Real-Time Operating System) sendiri memiliki arsitektur kernel tersendiri dimana tipe kernel yang ada adalah microkernel , monolithic kernel ,exokernel. Semua kernel ini dapat diterapkan dalam Embedded System sesuai dengan kebutuhan dan keperluan pembuat suatu Embedded System, dimana setiap kernel memiliki kelebihan dan kekurangan masing-masing.

Supporting hot-swappable components allows components to be replaced even while they may be in active use. This can allow live upgrades to running systems, more adaptable software that can change its behaviour at run-time by swapping components, and a simpler software structure by allowing distinct policy and implementation options to be implemented in separate components (rather than as a single monolithic component) and dynamically swapped as needed. We describe in general the challenges that must be faced to support hot-swapping, then describe our prototype in the K42 operating system and provide some initial results.

K42 is an open-source research OS for 64-bit multiprocessor systems, focusing on the PowerPC ® architecture. It uses an object-oriented design to achieve good performance, scalability, customisability, and maintainability. K42 supports the Linux ® API and ABI allowing it to use unmodified Linux applications and libraries, and can be deployed by running on an existing installation of Linux. The development process of K42 is intended to share concepts with Linux; many ideas have been transferred between the two projects. K42 implements each system resource (such as an open file or process) as a set of unique object instances, and supports hot-swapping, which allows these objects to be changed on-the-fly. This enables dynamic reconfiguration and adaptability of the system, and when combined with a kernel module loader, supports dynamic update and hot patching of the OS. Examples of this might include dynamically adapting to file access patterns, or replacing insecure code in the network stack without downtime.

Dynamic update is a mechanism that allows software updates and patches to be applied to a running system without loss of service or down-time. Operating systems would benefit from dynamic update, but place unique demands on any implementation of such features. These demands stem from the event-driven nature of operating systems, from their restricted run-time execution environment, and from their role in simultaneously servicing multiple clients.

Patches to modern operating systems, including bug fixes and security updates, and the reboots and downtime they require, cause tremendous problems for system users and administrators. Dynamic update allows an operating system to be patched without the need for a reboot or other service interruption. We have taken the approach of building dynamic update functionality directly into an existing operating system, K42.

Online reconfiguration provides a way to extend and replace active operating system components. This provides administrators, developers, applications, and the system itself with a way to update code, adapt to changing workloads, pinpoint performance problems, and perform a variety of other tasks while the system is running. With generic support for interposition and hot-swapping, a system allows active components to be wrapped with additional functionality or replaced with different implementations that have the same interfaces. This paper describes support for online reconfiguration in the K42 operating system and our initial experiences using it. It describes four base capabilities that are combined to implement generic support for interposition and hot-swapping. As examples of its utility, the paper describes some performance enhancements that have been achieved with K42's online reconfiguration mechanisms including adaptive algorithms, common case optimizations, and workload specific specializations.

K42 is an open-source research OS for 64-bit multiprocessor systems, focusing on the PowerPC ® architecture. It uses an object-oriented design to achieve good performance, scalability, customisability, and maintainability. K42 supports the Linux ® API and ABI allowing it to use unmodified Linux applications and libraries, and can be deployed by running on an existing installation of Linux. The development process of K42 is intended to share concepts with Linux; many ideas have been transferred between the two projects. K42 implements each system resource (such as an open file or process) as a set of unique object instances, and supports hot-swapping, which allows these objects to be changed on-the-fly. This enables dynamic reconfiguration and adaptability of the system, and when combined with a kernel module loader, supports dynamic update and hot patching of the OS. Examples of this might include dynamically adapting to file access patterns, or replacing insecure code in the network stack without downtime.

Patches to modern operating systems, including bug fixes and security updates, and the reboots and downtime they require, cause tremendous problems for system users and administrators. Dynamic update allows an operating system to be patched without the need for a reboot or other service interruption. We have taken the approach of building dynamic update functionality directly into an existing operating system, K42.

Dynamic update is a mechanism that allows software updates and patches to be applied to a running system without loss of service or down-time. Operating systems would benefit from dynamic update, but place unique demands on any implementation of such features. These demands stem from the event-driven nature of operating systems, from their restricted run-time execution environment, and from their role in simultaneously servicing multiple clients.

Online reconfiguration provides a way to extend and replace active operating system components. This provides administrators, developers, applications, and the system itself with a way to update code, adapt to changing workloads, pinpoint performance problems, and ...

Supporting hot-swappable components allows components to be replaced even while they may be in active use. This can allow live upgrades to running systems, more adaptable software that can change its behaviour at run-time by swapping components, and a simpler software structure by allowing distinct policy and implementation options to be implemented in separate components (rather than as a single monolithic component) and dynamically swapped as needed. We describe in general the challenges that must be faced to support hot-swapping, then describe our prototype in the K42 operating system and provide some initial results.

K42 is an open-source, Linux-compatible, scalable operating-system kernel that can be used for rapid prototyping of operating-system policies and mechanisms. This paper reviews the structure and design philosophy of K42 and discusses our experiences in developing and using K42 in the open-source environment.

K42 is an open-source scalable research operating system well suited to support systems research. The primary goals of K42's design that support such research include flexibility to allow a multitude of policies and implementations to be supported simultaneously, extensibility to allow new policies and implementations to be readily added, and scalability to enable good performance for both small and large applications on both small and large multiprocessor systems. The goals are accomplished via key features including an objectoriented structure that allows specialized resource management implementations and policies on a per-resource, perapplication basis, implementation in user-level servers of much of the system functionality, and a sophisticated set of underlying services that provides a programming model for developing system software in a scalable and modular fashion.

The exokemel operating system architecture safely gives untrusted software efficient control over hardware and software resources by separating management from protection. This paper describes an exokemel system that allows specialized applications to achieve high performance without sacrificing the performance of unmodified UNIX programs. It evaluates the exokemel architecture by measuring end-to-end application performance on Xok, an exokernel for Intel x86-based computers, and by comparing Xok's performance to the performance of two widely-used 4.4BSD UNIX systems (FreeBSD and OpenBSD). The results show that common unmodified UNIX applications can enjoy the benefits of exokernels: applications either perform comparably on Xok/ExOS and the BSD UNIXes, or perform significantly better. In addition, the results show that customized applications can benefit substantially from control over their resources (e.g., a factor of eight for a Web server). This paper also describes insights about the exokemel approach gained through building three different exokemel systems, and presents novel approaches to resource multiplexing.

Kernel • The kernel is the central module of an operating system. It is the part of the operating system that loads first, and it remains in the main memory. Because it stays in the memory, it is important for the kernel to be as small as possible while still providing all the essential services required by other parts of the operating system and applications. Kernel has complete control over everything that occurs in the system.

Patches to modern operating systems, including bug fixes and security updates, and the reboots and downtime they require, cause tremendous problems for system users and administrators. Dynamic update allows an operating system to be patched without the need for a reboot or other service interruption. We have taken the approach of building dynamic update functionality directly into an existing operating system, K42.

Dynamic update is a mechanism that allows software updates and patches to be applied to a running system without loss of service or down-time. Operating systems would benefit from dynamic update, but place unique demands on any implementation of such features. These demands stem from the event-driven nature of operating systems, from their restricted run-time execution environment, and from their role in simultaneously servicing multiple clients.

UNIX memiliki tujuan dalam Computer Networking, maka kemampuan dari UNIX dalam memberikan jasa internet lebih berkembang dan lebih reliable. Banyak orang mengatakan bahwa bernetwork ria dengan UNIX lebih cepat dibandingkan dengan sistem operasi lain nya. Tetapi hal ini relatif, dikatakan relatif karena banyak faktor yang menentukan performasi network dan tidak semudah itu untuk dibandingkan.

Saat ini UNIX sudah tidak terbatas sebagai komputer server atau pemberi layanan internet. Sekarang UNIX sudah mampu menggantikan fungsi Windows sebagai komputer workstation atau alat untuk bekerja sehari-hari, dan lebih stabil. Hal ini disebabkan oleh perkembangan UNIX yang mulai terlihat prospeknya sebagai sistem operasi workstation uga, tanpa meninggalkan arah perkembangan dalam Computer Networking.

UNIX lebih stabil dibandingkan dengan sistem operasi lainnya, hal ini disebabkan konsep dan proses pembuatan karnel. Salah satu kestabilan UNIX adalah tidak pernah mengalami kegagalan sistem yang disebabkan oleh sistem oprerasi tersebut.

The performance of customized hardware systems known as embedded systems for telecom applications are determined by many factors. If performance is not meeting telecom application developer requirements we need to customize hardware or optimize application software to meet constraint of the telecom requirement. Optimization and Performance analysis is extremely important stage for telecom application developers who are working on customized hardware system platforms. There are different types of approaches to be optimization, which are greatly differing from each other techniques. This paper describes the optimization techniques for LAYER1 in IPBTS protocol stack application. It is used to increase the performance of task allocation on LAYER1 by reducing the density of code and to improve the performance and execution time of the on ARM11 Raspberry Pi processor board. The optimization and task allocation of real-time embedded systems are analyzed and optimized using functions, structures and pointers with results.

Detecting faces across multiple views is more challenging than in a frontal view. To address this problem,an efficient approach is presented in this paper using a kernel machine based approach for learning such nonlinear mappings to provide effective view-based representation for multi-view face detection. In this paper Kernel Principal Component Analysis (KPCA) is used to project data into the view-subspaces then
computed as view-based features. Multi-view face detection is performed by classifying each input image into face or non-face class, by using a two class Kernel Support Vector Classifier (KSVC). Experimental results demonstrate successful face detection over a wide range of facial variation in color, illumination conditions, position, scale, orientation, 3D pose, and expression in images from several photo collections

When designing a kernel for an operating system the developer has to choose between an microkernel or monolithic kernel approach. Bases for the decision is mostly the tradeoff between security and performance. Depending on application demands and on the available hardware a microkernel or a monolithic kernel approach or something between is desired. In this paper we present a hybrid kernel for embedded real-time systems which can be configured to the application demands in an easy way. To realize the hybrid kernel we present a technique to guarantee memory access in O(1) with virtual memory. With our approach the same codebase can be used for system services to be placed either in userspace or in kernelspace.

This paper introduced a remote monitor system of information appliance, it bases on the microprocessor of S3C2410 as the main controller and Linux as the embedded operate system. It represents the main function and composition of this system, through mounting the Web Server Boa and setting up the embedded remote visit and monitoring platform. Adopting HTML to design friendly man-machine interface. After completing the loading of USB camera driving and transplanting the video server, user can call on page of web server by web browser, implementing the monitoring of appliance by the internet.

Online reconfiguration provides a way to extend and replace active operating system components. This provides administrators, developers, applications, and the system itself with a way to update code, adapt to changing workloads, pinpoint performance problems, and perform a variety of other tasks while the system is running. With generic support for interposition and hot-swapping, a system allows active components to be wrapped with additional functionality or replaced with different implementations that have the same interfaces. This paper describes support for online reconfiguration in the K42 operating system and our initial experiences using it. It describes four base capabilities that are combined to implement generic support for interposition and hot-swapping. As examples of its utility, the paper describes some performance enhancements that have been achieved with K42's online reconfiguration mechanisms including adaptive algorithms, common case optimizations, and workload specific specializations.

K42 is an open-source research OS for 64-bit multiprocessor systems, focusing on the PowerPC ® architecture. It uses an object-oriented design to achieve good performance, scalability, customisability, and maintainability. K42 supports the Linux ® API and ABI allowing it to use unmodified Linux applications and libraries, and can be deployed by running on an existing installation of Linux. The development process of K42 is intended to share concepts with Linux; many ideas have been transferred between the two projects. K42 implements each system resource (such as an open file or process) as a set of unique object instances, and supports hot-swapping, which allows these objects to be changed on-the-fly. This enables dynamic reconfiguration and adaptability of the system, and when combined with a kernel module loader, supports dynamic update and hot patching of the OS. Examples of this might include dynamically adapting to file access patterns, or replacing insecure code in the network stack without downtime.

K42 is an open-source scalable research operating system well suited to support systems research. The primary goals of K42's design that support such research include flexibility to allow a multitude of policies and implementations to be supported simultaneously, extensibility to allow new policies and implementations to be readily added, and scalability to enable good performance for both small and large applications on both small and large multiprocessor systems. The goals are accomplished via key features including an objectoriented structure that allows specialized resource management implementations and policies on a per-resource, perapplication basis, implementation in user-level servers of much of the system functionality, and a sophisticated set of underlying services that provides a programming model for developing system software in a scalable and modular fashion.

Dynamic update is a mechanism that allows software updates and patches to be applied to a running system without loss of service or down-time. Operating systems would benefit from dynamic update, but place unique demands on any implementation of such features. These demands stem from the event-driven nature of operating systems, from their restricted run-time execution environment, and from their role in simultaneously servicing multiple clients.

Autonomic computing systems are designed to be self-diagnosing and self-healing, such that they detect performance and correctness problems, identify their causes, and react accordingly. These abilities can improve performance, availability, and security, while simultaneously reducing the effort and skills required of system administrators. One way that systems can support these abilities is by allowing monitoring code, diagnostic code, and function implementations to be dynamically inserted and removed in live systems. This "hot swapping" avoids the requisite prescience and additional complexity inherent in creating systems that have all possible configurations built in ahead of time. For already-complex pieces of code such as operating systems, hot swapping provides a simpler, higher-performance, and more maintainable method of achieving autonomic behavior. In this paper, we discuss hot swapping as a technique for enabling autonomic computing in systems software. First, we discuss its advantages and describe the required system structure. Next, we describe K42, a research operating system that explicitly supports interposition and replacement of active operating system code. Last, we describe the infrastructure of K42 for hot swapping and several instances of its use demonstrating autonomic behavior.