Efficient Page lock/release mechanism in OS for out-of-core Embedded Applications
Ameet Patil and Neil Audsley
In embedded systems, applications are becoming more complex and memory hungry, requiring an increase in the amount of physical memory. For low-power portable embedded systems with soft real-time requirements the addition of physical memory increases the system cost and contributes towards more power consumption. Virtual memory techniques such as paging make use of an inexpensive, low-power auxiliary memory allowing applications to use more memory than is available. However, paging yields poor performance due to the inherent page swapping overhead. This paper presents a combined approach of using application hints along with an efficient page lock/release mechanism in the OS to reduce paging overheads making paging a viable solution to support out-of-core embedded applications in soft real-time systems. The Co-operative Application Specific Paging (CASP) mechanism presented works in conjunction with most existing page replacement policies, providing explicit support for applications via insertion of paging hints in the application source code. Both automatic and manual methods of inserting hints have been described, compared and contrasted. The benchmark results of a CASP implementation in the Linux 2.6.16 kernel have shown significant reduction in the number of page-faults (22.3%) and a considerable improvement in application execution times (12.5
BibTex Entry
@inproceedings{Patil2007,
address = {Daegu, Korea},
author = {Ameet Patil and Neil Audsley},
booktitle = {Proceedings of the 13th IEEE Real-time and Embedded Computing Systems and Applications Symposium},
month = {August},
pages = {81--88},
title = {Efficient Page lock/release mechanism in OS for out-of-core Embedded Applications},
year = {2007}
}