kthread: Add __kthread_should_park() (0121805d) · Commits · 戴 / test

kthread_should_park() is used to check if the calling kthread ('current') should park, but there is no function to check whether an arbitrary kthread should be parked. The latter is required to plug a CPU hotplug race vs. a parking ksoftirqd thread. The new __kthread_should_park() receives a task_struct as parameter to check if the corresponding kernel thread should be parked. Call __kthread_should_park() from kthread_should_park() to avoid code duplication. Signed-off-by:

Matthias Kaehlcke <mka@chromium.org> Signed-off-by:

Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Douglas Anderson <dianders@chromium.org> Cc: Stephen Boyd <swboyd@chromium.org> Link: https://lkml.kernel.org/r/20190128234625.78241-2-mka@chromium.org

include/linux/kthread.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -56,6 +56,7 @@ void kthread_bind_mask(struct task_struct k, const struct cpumask mask);
		int kthread_stop(struct task_struct *k);
		bool kthread_should_stop(void);
		bool kthread_should_park(void);
		bool __kthread_should_park(struct task_struct *k);
		bool kthread_freezable_should_stop(bool *was_frozen);
		void kthread_data(struct task_struct k);
		void kthread_probe_data(struct task_struct k);

kernel/kthread.c

+7 −1

Original line number	Diff line number	Diff line
		@@ -101,6 +101,12 @@ bool kthread_should_stop(void)
		}
		EXPORT_SYMBOL(kthread_should_stop);

		bool __kthread_should_park(struct task_struct *k)
		{
		return test_bit(KTHREAD_SHOULD_PARK, &to_kthread(k)->flags);
		}
		EXPORT_SYMBOL_GPL(__kthread_should_park);

		/**
		* kthread_should_park - should this kthread park now?
		*
		@@ -114,7 +120,7 @@ EXPORT_SYMBOL(kthread_should_stop);
		*/
		bool kthread_should_park(void)
		{
		return test_bit(KTHREAD_SHOULD_PARK, &to_kthread(current)->flags);
		return __kthread_should_park(current);
		}
		EXPORT_SYMBOL_GPL(kthread_should_park);

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