Enhanced Resource Sharing in UNIX
نویسندگان
چکیده
UNIX provides a programming model for the user which gives an illusion of multiprocess-ing. On uniprocessors, this illusion works well, providing communication paths, process security and a simple programming environment. Unfortunately, this model is not powerful enough to take full advantage of modern multiprocessor hardware. This results from a design which uses data queueing and preemption to provide the multiprocessing illusion. Recent proposals for lightweight processes in UNIX show that other programming models may be effectively supported as well. These models provide for virtual address space sharing between tasks by breaking the process into several lightweight contexts that may be manipulated more quickly than a normal process. Unfortunately, such models raise questions about support for normal UNIX semantics , scheduling performance, and kernel overhead. retaining the key parts of the UNIX process model. The concept of a process is retained along with most of its semantics. The fundamental resource shared is the virtual address space. In addition, open file descriptors, user and group IDs, the current directory, and certain other elements of the process environment may be shared. This makes for easy construction of useful servers and simple concurrent applications, while providing high performance support for more computationally intensive applications. This implementation, labelled process share groups, allows normal process actions to take place easily, such as system calls, page faulting, signalling, pausing , and other actions which are ill-defined in other models. The paper describes the philosophy which drove the design, as well as details of the implementation , which is based on, and upwardly compatible with, AT&T v.3 UNIX. Performance of normal UNIX processes is maintained while providing support for high performance parallel programming.
منابع مشابه
Beyond Threads: Resource Sharing in UNIX
UNIX provides a programming model for the user which gives an illusion of multiprocessing. On uniprocessors, this illusion works well, providing communication paths, firewalls between processes and a simple programming environment. Unfortunately, the normal UNIX model does not provide the capabilities to take full advantage of modern multiprocessor hardware. This results from a design which use...
متن کاملEnhanced Flush+Reload Attack on AES
In cloud computing, multiple users can share the same physical machine that can potentially leak secret information, in particular when the memory de-duplication is enabled. Flush+Reload attack is a cache-based attack that makes use of resource sharing. T-table implementation of AES is commonly used in the crypto libraries like OpenSSL. Several Flush+Reload attacks on T-table implementat...
متن کاملThe Mediating Role of Trust and Organizational Commitment in the Relationship between Strategic Human Resource Management and Knowledge Sharing
The main purpose of this research project was to investigate the impact of Strategic Human Resource Management practices on knowledge sharing behavior among university faculty members. This research also studied the mediating role of trust and organizational commitment in the relationship between SHRM practices and knowledge sharing behavior. Following the positivist paradigm, this research ado...
متن کاملA Distributed System with a Centralized Organization
One of the most important potential benefits of workstation clusters (client/server computing systems) is resource sharing. By interconnecting a number of workstations using a suitable network, a large number of hardware and software resources can be made available to users. In comparison with centralized computer systems (mainframes) and shared memory multiprocessors systems, the availability ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Computing Systems
دوره 1 شماره
صفحات -
تاریخ انتشار 1988