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Commit 7db74df8 authored by Paul E. McKenney's avatar Paul E. McKenney Committed by Paul E. McKenney
Browse files

rcu: Move rcu_barrier_completion to rcu_state structure 



In order to allow each RCU flavor to concurrently execute its
rcu_barrier() function, it is necessary to move the relevant
state to the rcu_state structure.  This commit therefore moves the
rcu_barrier_completion global variable to a new ->barrier_completion
field in the rcu_state structure.

Signed-off-by: default avatarPaul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: default avatarJosh Triplett <josh@joshtriplett.org>
parent 24ebbca8

kernel/rcutree.c

+4 −5
Original line number Diff line number Diff line
@@ -158,7 +158,6 @@ unsigned long rcutorture_vernum; 
/* State information for rcu_barrier() and friends. */



static DEFINE_MUTEX(rcu_barrier_mutex);

static struct completion rcu_barrier_completion;



/*

 * Return true if an RCU grace period is in progress.  The ACCESS_ONCE()s
@@ -2275,7 +2274,7 @@ static void rcu_barrier_callback(struct rcu_head *rhp) 
	struct rcu_state *rsp = rdp->rsp;



	if (atomic_dec_and_test(&rsp->barrier_cpu_count))

		complete(&rcu_barrier_completion);

		complete(&rsp->barrier_completion);

}



/*
@@ -2325,7 +2324,7 @@ static void _rcu_barrier(struct rcu_state *rsp) 
	 * 6.	Both rcu_barrier_callback() callbacks are invoked, awakening

	 *	us -- but before CPU 1's orphaned callbacks are invoked!!!

	 */

	init_completion(&rcu_barrier_completion);

	init_completion(&rsp->barrier_completion);

	atomic_set(&rsp->barrier_cpu_count, 1);

	raw_spin_lock_irqsave(&rsp->onofflock, flags);

	rsp->rcu_barrier_in_progress = current;
@@ -2375,10 +2374,10 @@ static void _rcu_barrier(struct rcu_state *rsp) 
	 * CPU, and thus each counted, remove the initial count.

	 */

	if (atomic_dec_and_test(&rsp->barrier_cpu_count))

		complete(&rcu_barrier_completion);

		complete(&rsp->barrier_completion);



	/* Wait for all rcu_barrier_callback() callbacks to be invoked. */

	wait_for_completion(&rcu_barrier_completion);

	wait_for_completion(&rsp->barrier_completion);



	/* Other rcu_barrier() invocations can now safely proceed. */

	mutex_unlock(&rcu_barrier_mutex);

kernel/rcutree.h

+1 −0
Original line number Diff line number Diff line
@@ -401,6 +401,7 @@ struct rcu_state { 
						/* Task doing rcu_barrier(), */

						/*  or NULL if no barrier. */

	atomic_t barrier_cpu_count;		/* # CPUs waiting on. */

	struct completion barrier_completion;	/* Wake at barrier end. */

	raw_spinlock_t fqslock;			/* Only one task forcing */

						/*  quiescent states. */

	unsigned long jiffies_force_qs;		/* Time at which to invoke */