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Diffstat (limited to 'report/chapter2.tex')
| -rw-r--r-- | report/chapter2.tex | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/report/chapter2.tex b/report/chapter2.tex index 3a8dd52..754a33e 100644 --- a/report/chapter2.tex +++ b/report/chapter2.tex @@ -4,8 +4,8 @@ Arbitrary preemptions of tasks which are used in fixed priority preemptive sched Another solution to this problem is to use Fixed Priority Scheduling with Deferred Preemption (FPDS). FPDS allows for preemptions at pre-specified points within a task's execution. This has two main benefits. The first is that it allows for greater accuracy in determining the Worst Case Execution Time (WCET). By allowing preemptions at only specified points, we can more accurately predict the effect these preemptions will have on schedulability. More importantly, the second benefit which this provides is that it reduces the costs of preemption through selecting appropriate points of preemption. In selecting the preemption points, we can limit preemptions to take place at points where less amount of cache reloads are required, hence reducing the costs of preemption. Therefore, special care has to be taken in selecting these preemption points. \\
-Let us first define two terms now. First, an active cache line is defined in [1] as a cache line that that contains a block of data that will be referenced in the future prior to its replacement. In other words, it is a cache line in which the next reference is a hit, had the task been allowed to run to completion.
-Secondly, a preferred preemption point for a given task interval $ t_i $ to $ t_j $ is defined in [1] as the instant within the interval having the minimum number of live cache lines. \\
+Let us first define two terms now. First, an active cache line is defined in \cite{sp-pppcbrts-95} as a cache line that that contains a block of data that will be referenced in the future prior to its replacement. In other words, it is a cache line in which the next reference is a hit, had the task been allowed to run to completion.
+Secondly, a preferred preemption point for a given task interval $ t_i $ to $ t_j $ is defined in \cite{sp-pppcbrts-95} as the instant within the interval having the minimum number of live cache lines. \\
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Bearing these in mind, the task we have at hand is to search for the preferred preemption points. There are two main ways that these points can be determined, using a compiler or manually. \\
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