High Priority Processes Research Articles

Pernerapan Algoritma Multilevel Feedback Queue (MFQ) & First In First Out (FIFO) pada Studi Kasus di Toko Bunga ARTHA PUSPA

Artha Puspa is a flower shop in Madiun which sells plant needs. This very rapid business development encourages every entrepreneur to create a form that is different from other businesses, one of which is the Arta Puspa Flower Shop, a common problem that is often experienced by Artha Puspa, namely direct purchase queues and orders. With that we use a combination of MFQ and FIFO. The application of a combination of Multilevel Feedback Queue (MFQ) and First In First Out (FIFO) algorithms is a strategy that can be used to manage processes that occur in computer systems. MFQ is a scheduling algorithm that uses several levels of queues, each of which has a different priority. Each process will be placed in a queue level according to its priority. Meanwhile, FIFO is a scheduling algorithm that manages processes by issuing processes that apply a combination of multilevel feedback queue (MFQ) & first in first out (FIFO) algorithms in the case study of the Bunga Artha Puspa store to enter the system for the first time. The combination of the two algorithms can provide a more effective solution in managing processes in computer systems. MFQ is a scheduling algorithm that uses several levels of queues, each of which has a different priority. Each process will be placed in a queue level according to its priority. Meanwhile, FIFO is a scheduling algorithm that manages processes by issuing processes that apply a combination of multilevel feedback queue (MFQ) & first in first out (FIFO) algorithms in the case study of the Bunga Artha Puspa store to enter the system for the first time. The combination of the two algorithms can provide a more effective solution in managing processes in computer systems. MFQ can be used to manage high priority processes, while FIFO can be used to manage low priority processes. Thus, processes that have high priority will always be processed first, thereby increasing system efficiency. In addition, the combination of MFQ and FIFO can also help reduce the waiting time for processes that have low priority, thereby increasing user satisfaction.

Regression modelling of conditional morphogene expression links and quantifies the impact of growth rate, fitness and macromorphology with protein secretion in Aspergillus niger

BackgroundFilamentous fungi are used as industrial cell factories to produce a diverse portfolio of proteins, organic acids, and secondary metabolites in submerged fermentation. Generating optimized strains for maximum product titres relies on a complex interplay of molecular, cellular, morphological, and macromorphological factors that are not yet fully understood.ResultsIn this study, we generate six conditional expression mutants in the protein producing ascomycete Aspergillus niger and use them as tools to reverse engineer factors which impact total secreted protein during submerged growth. By harnessing gene coexpression network data, we bioinformatically predicted six morphology and productivity associated ‘morphogenes’, and placed them under control of a conditional Tet-on gene switch using CRISPR-Cas genome editing. Strains were phenotypically screened on solid and liquid media following titration of morphogene expression, generating quantitative measurements of growth rate, filamentous morphology, response to various abiotic perturbations, Euclidean parameters of submerged macromorphologies, and total secreted protein. These data were built into a multiple linear regression model, which identified radial growth rate and fitness under heat stress as positively correlated with protein titres. In contrast, diameter of submerged pellets and cell wall integrity were negatively associated with productivity. Remarkably, our model predicts over 60% of variation in A. niger secreted protein titres is dependent on these four variables, suggesting that they play crucial roles in productivity and are high priority processes to be targeted in future engineering programs. Additionally, this study suggests A. niger dlpA and crzA genes are promising new leads for enhancing protein titres during fermentation.ConclusionsTaken together this study has identified several potential genetic leads for maximizing protein titres, delivered a suite of chassis strains with user controllable macromorphologies during pilot fermentation studies, and has quantified four crucial factors which impact secreted protein titres in A. niger.

CLPKM: A checkpoint-based preemptive multitasking framework for OpenCL kernels

Abstract Heterogeneous computing has become popular in the past decade. Many frameworks have been proposed to provide a uniform way to program for accelerators, such as GPUs, DSPs, and FPGAs. Among them, an open and royalty-free standard, OpenCL, is widely adopted by the industry. However, many OpenCL-enabled accelerators and the standard itself do not support preemptive multitasking. To the best of our knowledge, previously proposed techniques are not portable or cannot handle ill-designed kernels (the codes that are executed on the accelerators), which will never ever finish. This paper presents a framework (called CLPKM ) that provides an abstraction layer between OpenCL applications and the underlying OpenCL runtime to enable preemption of a kernel execution instance based on a software checkpointing mechanism. CLPKM includes (1) an OpenCL runtime library that intercepts OpenCL API calls, (2) a source-to-source compiler that performs the preemption-enabling transformation, and (3) a daemon that schedules OpenCL tasks using priority-based preemptive scheduling techniques. Experiments demonstrated that CLPKM reduced the slowdown of high-priority processes from 4.66x to 1.52–2.23x under up to 16 low-priority, heavy-workload processes running in the background and caused an average of 3.02–6.08x slowdown for low-priority processes.

An Improved Round Robin CPU Scheduling Algorithm based on Priority of Process

The most important and integral part of a computer system is its operating system. Scheduling various resources is one of the most critical tasks an operating system needs to perform. Process scheduling being one of those tasks, involves various techniques that define how more than one processes can be executed simultaneously. The primary aim here is to the system more efficient and faster. The fundamental scheduling algorithms are: First Come First Serve (FCFS), Round Robin, Priority Based Scheduling, and Shortest Job First (SJF). This paper focuses on Round Robin Scheduling algorithm and various issues related to it. One major issue in RR scheduling is determining the length of Time Quantum. If the Time Quantum is too large RR scheduling behaves as FCFS. On the other hand, if it is too small it forces considerable increase in the number of context switches. Our main objective is to overcome this limitation of traditional RR scheduling algorithm and maximize CPU utilization, further, leading to more efficient and faster system. Here we propose an algorithm that categorizes available processes into High Priority processes and Low Priority process. The proposed algorithm reduces the average waiting time of High Priority processes in all cases and of Low Priority processes in not all but some cases. The overall waiting time changes on the basis of set of processes considered. The simulation results justify that the proposed schemes reduces the overall average waiting time when compared to the existing schemes.

RGB Color Image Encryption-Decryption Using Image Segmentation and Matrix Multiplication

Digital RGB color images are considered as the most widely used data type through the internet, so there is a need for efficient and secure techniques to transmit and protect these digital images and this is a matter of high priority process. Many researchers had developed different techniques to increase the security of image transmission, and most of these techniques suffer from the low speed of the encryption-decryption process. In this paper, a novel technique is proposed that could be used for digital color image encryption-decryption. The performance of this technique is compared with the performance of other techniques and it has shown the advantages of using this technique over other techniques in enhancing the throughput and speed of encryption-decryption process.

An integrated monitoring framework for the Great Barrier Reef World Heritage Area

Monitoring provides important feedback on how social and environmental systems are tracking and whether or not human activities, including management activities, are having an impact. This paper describes an approach applied to develop an integrated monitoring framework to inform adaptive management of the Great Barrier Reef World Heritage Area, a complex, multi-jurisdictional, multi-sectoral marine system of international importance. It identifies the gaps and opportunities to integrate the existing long-term, short-term and compliance-related monitoring and reporting initiatives to provide the information for more effective and efficient (adaptive) management of the Great Barrier Reef World Heritage Area. And as importantly it aligns expectations among different agencies about how monitoring will inform management. Fifty two high priority values, processes and pressures for management were identified along with 65 existing monitoring programs. Developing the monitoring framework was useful in several ways. First it brought together scientists, policy-makers, managers, and other interested stakeholders with different agendas, philosophies and incentives and established a common purpose, lexicon and language for an integrated monitoring program. Second, it highlighted the importance and usefulness of qualitative conceptual models as a framework for focused discussion around a set of hypotheses with relevance for management. Third, the process started an important conversation about defining and setting a realistic number of monitoring priorities for management. Finally, it has provided direction for how to build on existing initiatives to develop an integrated monitoring program for a globally significant world heritage area.

New MLFQ Scheduling Algorithm for Operating Systems Using Dynamic quantum

The new design of multilevel feedback queue will depend on usage new technique in computing the quantum to produce (ADQ) Auto Detect Quantum which is relied on the burst of each process has enrolled to the system. By summating the burst time of each process has arrived and dividing it by the number of available processes, we can obtained the dynamic quantum in each level of scheduling. The processes are scheduled and shifted down from queue to other according to their remaining bursts time that should be updated periodically. Every queue has a unique auto detected quantum which is gradually increased or decreased from top level to bottom level queues according to the case of arriving processes. Depending on the results of graphical simulating algorithm on cases study, we can discover that a dynamic quantum is very suitable to accommodate low priority processes that still for a long duration to complete their requests, i.e. avoid the starvation of CPU- bounded processes. Although, it stills compatible with high priority processes (I/O-Bounded) to provide a fair interactivity with them. In comparison to traditional MLFQ the performance of the new scheduling technique is better and practical according to the applied results. Additional, we developed suitable software to simulate the new design and test it on different cases to prove it.

Enabling preemptive multiprogramming on GPUs

GPUs are being increasingly adopted as compute accelerators in many domains, spanning environments from mobile systems to cloud computing. These systems are usually running multiple applications, from one or several users. However GPUs do not provide the support for resource sharing traditionally expected in these scenarios. Thus, such systems are unable to provide key multiprogrammed workload requirements, such as responsiveness, fairness or quality of service. In this paper, we propose a set of hardware extensions that allow GPUs to efficiently support multiprogrammed GPU workloads. We argue for preemptive multitasking and design two preemption mechanisms that can be used to implement GPU scheduling policies. We extend the architecture to allow concurrent execution of GPU kernels from different user processes and implement a scheduling policy that dynamically distributes the GPU cores among concurrently running kernels, according to their priorities. We extend the NVIDIA GK110 (Kepler) like GPU architecture with our proposals and evaluate them on a set of multiprogrammed workloads with up to eight concurrent processes. Our proposals improve execution time of high-priority processes by 15.6x, the average application turnaround time between 1.5x to 2x, and system fairness up to 3.4x

Dynamic Partition of Shared Cache for Multi-Thread Application in Multi-Core System

In a chip-multiprocessor with a shared cache structure , the competing accesses from different applications degrade the system performance.The accesses degrade the performance and result in non-predicting executing time. Cache partitioning techniques can exclusively partition the shared cache among multiple competing applications. In this paper, the authors design the framework of Process priority-based Multithread Cache Partitioning(PP-MCP),a dynamic shared cache partitioning mechanism to improve the performance of multi-threaded multi-programmed workloads. The framework includes a miss rate monitor , called Application-oriented Miss Rate Monitor (AMRM) , which dynamically collect s miss rate information of multiple multi-threaded applications on different cache partitions , and process priority-based weighted cache partitioning algorithm ,which extends traditional miss rate oriented cache partition algorithms.The algorithm allocates Cache in sequence of the value of the process priority and it ensures that the highest priority process will get enough Cache space; and the applications with more threads tend to get more shared cache in order to improve t he overall system performance. Experiments show that PP-MCP has better IPC throughput and weighted speedup. Specifically , for multi-threaded multi-programmed scientific computing workloads , PP-MCP-1 improves throughput by up to 20% and on average 10 % over PP-MCP-0.

종단간 QoS 지원을 위해 Bottom-half 메커니즘을 이용한 우선순위 및 예산 기반의 네트워크 프로토콜 처리

종단 호스트에서의 전통적인 네트워크 프로토콜 처리 기법은 인터럽트 기반의 선착순 처리 방식을 사용함으로써 다음과 같은 두 가지 문제점을 가진다. 첫째, 인터럽트가 가장 높은 우선순위로 처리되기 때문에 네트워크 패킷과 응용 프로세스간에 우선순위 역전현상이 발생할 수 있다. 둘째, 네트워크 패킷 처리가 선착순으로 진행되기 때문에 패킷과 패킷간에 우선순위 역전현상이 발생할 수 있다. 이러한 문제는 우선순위에 기반한 프로토콜 처리 방법으로 해결이 가능한 것으로 알려져 있지만, 기본적으로 우선순위 기반의 해법은 기아(starvation)라는 부작용을 가지고 있으며 각각의 네트워크 흐름에 대하여 QoS 격리 및 조절이 불가능하기 때문에 네트워크 흐름마다 상이한 QoS가 요구되는 환경에 적용하기 어렵다는 문제점을 가지고 있다. 본 논문에서는 우선순위와 예산(budget) 개념에 기반하여 bottom-half 메커니즘을 이용한 프로토콜 처리 기법을 제안한다. 제안하는 방법을 사용하면 우선순위 기반의 프로토콜 처리 방법이 가지고 있는 기아 현상을 해결함은 물론 각각의 네트워크 연결이 요구하는 QoS의 격리(isolation)가 가능하다. 이러한 특성으로 인해 패킷 처리 시간을 상한 (upper-bound)시키는 것이 가능해지며, 본 논문에서는 그 최대값을 계산해내는 방법을 함께 제안한다. 마지막으로, 실험을 통해 제안하는 방법이 네트워크 흐름간 QoS를 효과적으로 격리 및 조절할 수 있음을 확인할 수 있었다. The traditional interrupt-based protocol processing at end hosts has two priority-inversion problems. First, low-priority packets may interrupt and delay high-priority process executionssince interrupts have the highest priority in most operating systems. Second, low-priority packet may delay high priority packets when they arrive almost simultaneously since interrupt processing is performed in a FCFS (first come, first served) order. These problems can be solved by a priority-based protocol processing policy and implementation. However, general priority-based schemes commonly have the problem of starvation and cannot support the each network flow requiring the mutually exclusive QoS since the packets are processed in the FCFS order. Therefore, the priority-based schemes are not appropriate for different QoS-demanding applications. In this paper, we present a bottom-half-based approach that relies on priority- and budget-based processing. The proposed approach allows us to solve both the starvation and priority-inversion problems, and further enables effective QoS isolation between different network connections. This feature also enables bounding the protocol processing time at an end host. We finally show through experiments that the proposed approach achieves QoS isolation and control.

Depth-related variation in regeneration of artificial lesions in the Caribbean corals Porites astreoides and Stephanocoenia michelinii

Regeneration of artificial lesions was studied along a depth gradient from 5–35 m in the Caribbean corals Porites astreoides (brown morph) and Stephanocoenia michelinii (massive morph). During the first 3–4 weeks of the regeneration process tissue recovery in both coral species was higher in shallow water than in deep water colonies. After 7 weeks when the lesions were almost closed, however, shallow as well as deep water colonies had restored the damage to the same degree, showing that regeneration is a high priority process in coral ecology. The deep water colonies did not show signs of photoacclimatization. The zooxanthellae densities and the total chlorophyll concentration per algal cell in the coral tissue did not vary significantly with depth. Furthermore, there was no decrease with depth of the chlorophyll a/ c 2 ratio, which would have indicated photoacclimatization by means of a relative increase of chlorophyll c 2 which is more efficient in using the blue light available at depth. One possibility which may explain the slower tissue recovery in deep water colonies during the first stage of the regeneration process, is a combination of the reduced light levels at depth and a lack of chlorophyll acclimatization in the deep water colonies.

Real-time parallel architecture for sensor fusion

Sensor fusion is an example of an intelligent system which must simultaneously process a large amount of sensor data and perform intelligent computations. To satisfy the enormous computational requirements of such a system, we believe it must be implemented on a parallel architecture with special support for real-time computation. This paper describes a real-time parallel architecture that can handle sensor fusion processing by using processors tightly coupled with a priority handling network. The processor has a priority queue, which sends the two highest priority processes to the execution part of the processor. The processor has two pipelines: one is dedicated to the execution of the highest priority process, and the other is used to handle inserted instructions and to dynamically process administration during execution of the next highest priority process. Synchronization can be implemented with register read and write operations, which effectively provide very high speed fine-grain synchronization. When a currently executing thread must wait for a synchronization, the processor can switch contexts quickly by using hardware-supported multiple context register sets. The network is a prioritized multi-stage network which avoids the priority inversion problem, giving predictable process execution times to the system, and enabling its use for intelligent, real-time applications.

Multiprocessor Synchronization Primitives with Priorities

Abstract Low-level multiprocessor synchronization primitives, such as spinlocks, are usually designed with little or no consideration about timing constraints, which makes them inappropriate for real-time systems. In this paper, we propose a new synchronization mechanism, the priority spinlock , that takes into account the priorities of the processes that want to acquire it, and favors high priority processes. We define what a priority spinlock is, and propose two algorithms to implement priority spinlocks with local spinning. Priority spinlocks can be used to provide prioritized mutually exclusive access to shared resources in real-time multiprocessor systems. They can also be used as building blocks for higher level priority synchronization primitives, such as priority semaphores.

Formal specifications and proofs of inheritance protocols for real-time scheduling

Priority is one means of representing scheduling information in a concurrent real-time programming language. Unfortunately, a static priority scheme can give rise to inversion when combined with synchronisation primitives. In this paper the use of semaphores for protecting access to critical regions is investigated. The formal notation Z is used for this treatment. It is shown that the normal semantics for semaphores can lead to a high priority process being delayed indefinitely. The inclusion of inheritance into the semaphore model improves the situation, but delays can still be significant. To overcome this lack of responsiveness, Lui Sha et al. [1] have developed a ceiling protocol that both removes the possibility of deadlock and limits (to one) the number of times a high priority process can be blocked. This paper contains a formal specification of a complete and a simplified version of the ceiling protocol, together with proofs of their important properties. The simplified version is suitable only for soft real-time systems and was generated while working from an incomplete natural language description given by Sha. The results of the proofs give considerable insight into the ceiling protocols and clarify many areas of their operation.

An enhanced realtime multitasking BASIC interpreter

This paper describes the implementation of an enhanced BASIC interpreter which provides the necessary features to support program execution in a realtime multitasking environment. The interpreter supports many of the features found in commercial realtime executives (RTXs) including process scheduling, message-based interprocess communication, interprocess synchronization and control, dynamic process creation/destruction, memory management, external event (interrupt) synchronization, and basic timing services. The kernel employs a preemptive scheduling policy based on process priority and allotted time-slice. To retain compatibility, the interpreter operates in a default single process mode if the multitasking extensions are not utilized. The interpreter is completely reentrant and may perform a context switch at any point during the execution of the current process. This allows a fast response to high priority processes made ready to execute by the occurrence of an external interrupt. The interpreter is mainly written in C and is portable to different microprocessor families. It is currently implemented for the i8088/86/186/286 family and has been ported to the IBM PC compatible systems.