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http://hdl.handle.net/123456789/527
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| Title: | Fortifying the operating system CPU scheduler |
| Authors: | Lakuma, Joel |
| Keywords: | CPU Scheduler
Operating system
Central Processing Unit |
| Issue Date: | 18-Nov-2009 |
| Abstract: | Central processing unit (CPU) scheduling is the mechanism by which operating systems allocate the CPU resources to processes. Scheduling is required for multiprogramming.
The scheduler performs context-switching to change process states and hence share the CPU. This is an expensive necessity since processing time is lost in the intermmediate period between the execution of two processes. In current scheduler designs, rogue code can exploit this feature and reduce on CPU usage and scheduler efficiency, or even cripple computing. This study carried out on the Linux 2.6.11 scheduler, had the aim of improving on the existing scheduler to enable it to withstand such rogue code and set a minimum level of efficiency. Building
on the existing Linux 2.6.11 CPU scheduler, the study developed a scheduler algorithm
with inherent protection against excessive context switching, implemented a prototype scheduler from this algorithm, and carried out benchmark tests on the prototype. In this study a mechanism was used to monitor the rate of task preemption and tie this measured value to the condition used to test whether the next preemption would be permitted. The performance of the protype was comparable to that of the Linux 2.6.11 scheduler. The superforker code was used to verify the stability of the resulting design. Unlike the Linux 2.6.11 scheduler, the protype scheduler withstood attacks due to to this rogue code. |
| Description: | A Project Report submitted in partial fulfillment of the requirements for the award of the Degree of Master of Science in Computer Science of Makerere University |
| URI: | http://hdl.handle.net/123456789/527 |
| Appears in Collections: | Theses & Dissertations (CIT)
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Files in This Item:
| File |
Description |
Size | Format |
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| lakuma-joel-cit-masters-report.pdf | | 373Kb | Adobe PDF | View/Open |
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