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Daniel Bristot de Oliveira
10bde81c74
The wakeup in preemptive (wip) monitor verifies if the
wakeup events always take place with preemption disabled:
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v
#==================#
H preemptive H <+
#==================# |
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| preempt_disable | preempt_enable
v |
sched_waking +------------------+ |
+--------------- | | |
| | non_preemptive | |
+--------------> | | -+
+------------------+
The wakeup event always takes place with preemption disabled because
of the scheduler synchronization. However, because the preempt_count
and its trace event are not atomic with regard to interrupts, some
inconsistencies might happen.
The documentation illustrates one of these cases.
Link: https://lkml.kernel.org/r/c98ca678df81115fddc04921b3c79720c836b18f.1659052063.git.bristot@kernel.org
Cc: Wim Van Sebroeck <[email protected]>
Cc: Guenter Roeck <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Marco Elver <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: "Paul E. McKenney" <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Gabriele Paoloni <[email protected]>
Cc: Juri Lelli <[email protected]>
Cc: Clark Williams <[email protected]>
Cc: Tao Zhou <[email protected]>
Cc: Randy Dunlap <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Daniel Bristot de Oliveira <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>
17 lines
602 B
Plaintext
17 lines
602 B
Plaintext
digraph state_automaton {
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{node [shape = circle] "non_preemptive"};
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{node [shape = plaintext, style=invis, label=""] "__init_preemptive"};
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{node [shape = doublecircle] "preemptive"};
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{node [shape = circle] "preemptive"};
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"__init_preemptive" -> "preemptive";
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"non_preemptive" [label = "non_preemptive"];
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"non_preemptive" -> "non_preemptive" [ label = "sched_waking" ];
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"non_preemptive" -> "preemptive" [ label = "preempt_enable" ];
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"preemptive" [label = "preemptive"];
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"preemptive" -> "non_preemptive" [ label = "preempt_disable" ];
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{ rank = min ;
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"__init_preemptive";
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"preemptive";
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}
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}
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