• Journal of Internet Computing and Services
• /
• v.11 no.4
• /
• pp.95-106
• /
• 2010

Recently multiple process communicate together. They share resource and information for cooperation in complicated programming environment. Kernel provides IPC (Inter -Process Communication) for communication with each other process. Shared Memory is a technique that many processes can access to identical memory area in the Linux environment. In this paper, we propose a performance improvement method of shared memory in the dual-core embedded linux system which is consist of different core and different operating system. We construct the MPC2530F (ARM926F+ARM946E) linux system and measure the performance therein. We attempt a performance enhancement in each CPU for each process which uses a shared memory.

• Journal of KIISE:Computer Systems and Theory
• /
• v.36 no.3
• /
• pp.181-190
• /
• 2009

Module is an object file that can be loaded into operating system dynamically and has complete privileged access to all resources in kernel. Therefore trivial misuses in a module may cause critical system halts or deadlock situations. In this paper, we propose Kernel Resource Protector(KRP) scheme to reduce the various problems caused by module. KRP provides protections of a variety of kernel resources such as memory, major number and work queue resource. We implement the scheme onto linux kernel 2.6.18, and experimental results show that our scheme can protect kernel resources effectively.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2006.05a
• /
• pp.1195-1198
• /
• 2006

기존의 컴퓨터 시스템에서는 인터넷의 대표적인 통신 프로토콜인 TCP/IP 가 호스트 CPU 에서 처리되는데, 이는 호스트 CPU 에 많은 부하(load)를 발생시켜 전체 시스템의 성능을 저하시키는 문제를 야기한다. 최근 이러한 문제점을 해결하는 방안으로서 네트워크 어댑터에서 TCP/IP 를 처리하는 TOE(TCP/IP Offload Engine)에 대한 연구가 활발히 진행되고 있다. 이러한 TOE 가 성공적으로 컴퓨터 시스템에 적용되는 위해서는 이를 지원하는 운영체제용 커널 모듈의 개발이 필요하며, 커널 모듈은 기존의 TCP/IP 를 위한 소켓 인터페이스를 바이너리 수준에서 호환성을 제공해야 한다. 따라서, 본 논문에서는 Linux 시스템에서 소켓 인터페이스에 대한 바이너리 수준의 호환성을 제공하는 TOE 용 커널 모듈을 제안하고 개발하였다. 또한, 실험의 통하여 TOE 커널 모듈이 CPU 에 부하를 거의 발생시키지 않음을 확인하였다.

• Proceedings of the IEEK Conference
• /
• 2008.06a
• /
• pp.649-650
• /
• 2008

In order to resolve mechanical limit in HDD, recently, the hybrid hard disk combining HDD and a flash memory was launched. In this paper, we propose a simulator for hybrid hard disk which considers redirection, flushing and spin-down function to complement the difference between HDD and hybrid hard disk. The simulator was implemented in linux kernel 2.6.20 by modifying system calls related with file system. The experiment shows that the power consumption of hybrid hard disk is 47% smaller than that of hard disk in laptop PC.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.5 no.4
• /
• pp.270-275
• /
• 2005

As the features of mobile phones are being enhanced and the performance is being greatly improved, the generic operating systems are being incrementally used in mobile phones. However, since the mobile phones have different requirements in both features and performance compared with desktop or server systems, the operating systems for generic systems could not be used without customization and modification. This case study paper describes the design and implementation of a Linux-based smartphone hardware and software. The enhancements and additional implementations in both kernel and middleware layers are explained. As an experiment, the power consumption of the implemented mobile phone under a number of user scenarios has been measured.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2002.04a
• /
• pp.381-384
• /
• 2002

This paper describes the motivation, design and performance of bi-active Load balancer in Linux Virtual Server. The goal of bi-active Load balancer is to provide a framework to build highly scalable, fault-tolerant services using a large cluster of commodity servers. The TCP/IP stack of Linux Kernel is extended to support three IP load balancing techniques, which can make parallel services of different kinds of server clusters to appear as a service on a single IP address. Scalability is achieved by transparently adding or removing a node in the cluster. and high availability is provided by detecting node or daemon failures and reconfiguring the system appropriately. Extensive simulation reveals that the proposed approach improves the reply rate about 20% compared to earlier design.

• Journal of the Semiconductor & Display Technology
• /
• v.20 no.2
• /
• pp.131-136
• /
• 2021

EtherCAT is an Ethernet-based fieldbus system standardized in IEC 61158 and SEMI, and widely used in the fields of factory automation, semiconductor equipment and robotics. In this paper, a real-time EtherCAT master is implemented on Linux operating systems and its performances are evaluated. To enhance the real-time capability of mainline Linux kernel, Xenomai is applied as a real-time framework and an open source EtherCAT master stack, Simple Open EtherCAT Master (SOEM), is installed on it. Unlike other studies, the real-time performance of the EtherCAT master is evaluated at the output of the network interface card, so that the evaluation results include all possible effects from the EtherCAT master system. The implemented EtherCAT master can send and receive packets up to 20KHz control frequency with low jitter, even in stressed condition.

• Journal of Advanced Navigation Technology
• /
• v.21 no.1
• /
• pp.78-83
• /
• 2017

Linux was born under the influence of Unix except for the kernel, Linux was used to bring the Unix system and relevant program package, commands, etc. However, the latest version of Enterprise Linux, RHEL 7 was adopted systemd instead of init to boot program and management services. The adoption of systemd was building its own Linux system, the system only. Also noteworthy point is that given the considerable number of features specific to a particular package and instructions. As Linux has been recognized as a subtype of Unix itself as a catch all this time the turn of the tide in the cloud era and there on their own to try various changes, the start of the adoption of these changes can be called systemd. Linux is the future beyond the confines of Unix is noteworthy not attempt any changes.

• Proceedings of the Korean Information Science Society Conference
• /
• 2010.11a
• /
• pp.88-89
• /
• 2010

• Proceedings of the Korean Information Science Society Conference
• /
• 2007.06a
• /
• pp.244-245
• /
• 2007