Commit 191a43be authored Apr 23, 2020 by Davidlohr Bueso Committed by Paolo Bonzini May 13, 2020

rcuwait: Introduce rcuwait_active()



This call is lockless and thus should not be trusted blindly.
For example, the return value of rcuwait_wakeup() should be used to
track whether a process was woken up.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Message-Id: <20200424054837.5138-5-dave@stgolabs.net>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

parent 5c21f7b3

include/linux/rcuwait.h

+9 −0

Original line number	Diff line number	Diff line
		@@ -25,6 +25,15 @@ static inline void rcuwait_init(struct rcuwait *w)
		w->task = NULL;
		}

		/*
		* Note: this provides no serialization and, just as with waitqueues,
		* requires care to estimate as to whether or not the wait is active.
		*/
		static inline int rcuwait_active(struct rcuwait *w)
		{
		return !!rcu_dereference(w->task);
		}

		extern int rcuwait_wake_up(struct rcuwait *w);

		/*

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