46 lines
1.1 KiB
ReStructuredText
46 lines
1.1 KiB
ReStructuredText
Monitor wwnr
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============
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- Name: wwrn - wakeup while not running
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- Type: per-task deterministic automaton
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- Author: Daniel Bristot de Oliveira <bristot@kernel.org>
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Description
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-----------
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This is a per-task sample monitor, with the following
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definition::
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v
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wakeup +-------------+
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+--------- | |
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| | not_running |
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+--------> | | <+
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+-------------+ |
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| |
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| switch_in | switch_out
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v |
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+-------------+ |
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| running | -+
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+-------------+
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This model is borken, the reason is that a task can be running
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in the processor without being set as RUNNABLE. Think about a
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task about to sleep::
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1: set_current_state(TASK_UNINTERRUPTIBLE);
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2: schedule();
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And then imagine an IRQ happening in between the lines one and two,
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waking the task up. BOOM, the wakeup will happen while the task is
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running.
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- Why do we need this model, so?
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- To test the reactors.
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Specification
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-------------
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Grapviz Dot file in tools/verification/models/wwnr.dot
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