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| <section id="effects-of-disabling-interrupts-or-pre-emption-on-response-latency"> |
| <h1>Effects of Disabling Interrupts or Pre-Emption on Response Latency<a class="headerlink" href="#effects-of-disabling-interrupts-or-pre-emption-on-response-latency" title="Permalink to this heading"></a></h1> |
| <section id="rate-monotonic-scheduling"> |
| <h2>Rate Monotonic Scheduling<a class="headerlink" href="#rate-monotonic-scheduling" title="Permalink to this heading"></a></h2> |
| <p><strong>Assumption</strong></p> |
| <blockquote> |
| <div><p>No resource sharing (processes do not share resources, e.g. a hardware |
| resource, a queue, or any kind of semaphore blocking or non-blocking |
| (busy-waits)).</p> |
| <p>Wikipedia “Rate Monotonic Scheduling”</p> |
| </div></blockquote> |
| <p><strong>Real world</strong></p> |
| <p>We must protect shared resources with locks of some kind. The most aggressive:</p> |
| <ol class="arabic simple"> |
| <li><p>Disabling interrupts, and</p></li> |
| <li><p>Disabling pre-emption.</p></li> |
| </ol> |
| <p>What are the effects of real-time performance when this assumptions is violated?</p> |
| <section id="normal-interrupt-processing"> |
| <h3>Normal Interrupt Processing<a class="headerlink" href="#normal-interrupt-processing" title="Permalink to this heading"></a></h3> |
| <figure class="align-center"> |
| <img alt="../_images/normal_interrupt.png" src="../_images/normal_interrupt.png" /> |
| </figure> |
| </section> |
| <section id="effect-of-disabling-interrupts"> |
| <h3>Effect of Disabling Interrupts<a class="headerlink" href="#effect-of-disabling-interrupts" title="Permalink to this heading"></a></h3> |
| <figure class="align-center"> |
| <img alt="../_images/disabling_interrupts.png" src="../_images/disabling_interrupts.png" /> |
| </figure> |
| </section> |
| <section id="effect-of-disabling-pre-emption"> |
| <h3>Effect of Disabling Pre-emption<a class="headerlink" href="#effect-of-disabling-pre-emption" title="Permalink to this heading"></a></h3> |
| <figure class="align-center"> |
| <img alt="../_images/disabling_preemption.png" src="../_images/disabling_preemption.png" /> |
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