ccc319dcb4
Per task wakeup while not running (wwnr) monitor. This model is broken, the reason is that a task can be running in the processor without being set as RUNNABLE. Think about a task about to sleep: 1: set_current_state(TASK_UNINTERRUPTIBLE); 2: schedule(); And then imagine an IRQ happening in between the lines one and two, waking the task up. BOOM, the wakeup will happen while the task is running. Q: Why do we need this model, so? A: To test the reactors. Link: https://lkml.kernel.org/r/473c0fc39967250fdebcff8b620311c11dccad30.1659052063.git.bristot@kernel.org Cc: Wim Van Sebroeck <wim@linux-watchdog.org> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Marco Elver <elver@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Gabriele Paoloni <gpaoloni@redhat.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: Tao Zhou <tao.zhou@linux.dev> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-trace-devel@vger.kernel.org Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
46 lines
1.1 KiB
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46 lines
1.1 KiB
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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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