From ccc319dcb450d57b7befe924453d06804d83ba73 Mon Sep 17 00:00:00 2001
From: Daniel Bristot de Oliveira <bristot@kernel.org>
Date: Fri, 29 Jul 2022 11:38:53 +0200
Subject: rv/monitor: Add the wwnr monitor

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>
---
 kernel/trace/rv/monitors/wwnr/wwnr.h | 46 ++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)
 create mode 100644 kernel/trace/rv/monitors/wwnr/wwnr.h

(limited to 'kernel/trace/rv/monitors/wwnr/wwnr.h')

diff --git a/kernel/trace/rv/monitors/wwnr/wwnr.h b/kernel/trace/rv/monitors/wwnr/wwnr.h
new file mode 100644
index 000000000000..d1afe55cdd4c
--- /dev/null
+++ b/kernel/trace/rv/monitors/wwnr/wwnr.h
@@ -0,0 +1,46 @@
+/*
+ * Automatically generated C representation of wwnr automaton
+ * For further information about this format, see kernel documentation:
+ *   Documentation/trace/rv/deterministic_automata.rst
+ */
+
+enum states_wwnr {
+	not_running_wwnr = 0,
+	running_wwnr,
+	state_max_wwnr
+};
+
+#define INVALID_STATE state_max_wwnr
+
+enum events_wwnr {
+	switch_in_wwnr = 0,
+	switch_out_wwnr,
+	wakeup_wwnr,
+	event_max_wwnr
+};
+
+struct automaton_wwnr {
+	char *state_names[state_max_wwnr];
+	char *event_names[event_max_wwnr];
+	unsigned char function[state_max_wwnr][event_max_wwnr];
+	unsigned char initial_state;
+	bool final_states[state_max_wwnr];
+};
+
+struct automaton_wwnr automaton_wwnr = {
+	.state_names = {
+		"not_running",
+		"running"
+	},
+	.event_names = {
+		"switch_in",
+		"switch_out",
+		"wakeup"
+	},
+	.function = {
+		{       running_wwnr,      INVALID_STATE,   not_running_wwnr },
+		{      INVALID_STATE,   not_running_wwnr,      INVALID_STATE },
+	},
+	.initial_state = not_running_wwnr,
+	.final_states = { 1, 0 },
+};
-- 
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