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Commit 06668efa authored by Paul E. McKenney's avatar Paul E. McKenney Committed by Paul E. McKenney
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rcu: Move _rcu_barrier()'s rcu_head structures to rcu_data structures 



In order for multiple flavors of RCU to each concurrently run one
rcu_barrier(), each flavor needs its own per-CPU set of rcu_head
structures.  This commit therefore moves _rcu_barrier()'s set of
per-CPU rcu_head structures from per-CPU variables to the existing
per-CPU and per-RCU-flavor rcu_data structures.

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 037b64ed

kernel/rcutree.c

+2 −4
Original line number Diff line number Diff line
@@ -157,7 +157,6 @@ unsigned long rcutorture_vernum; 


/* State information for rcu_barrier() and friends. */



static DEFINE_PER_CPU(struct rcu_head, rcu_barrier_head) = {NULL};

static atomic_t rcu_barrier_cpu_count;

static DEFINE_MUTEX(rcu_barrier_mutex);

static struct completion rcu_barrier_completion;
@@ -2282,12 +2281,11 @@ static void rcu_barrier_callback(struct rcu_head *notused) 
 */

static void rcu_barrier_func(void *type)

{

	int cpu = smp_processor_id();

	struct rcu_head *head = &per_cpu(rcu_barrier_head, cpu);

	struct rcu_state *rsp = type;

	struct rcu_data *rdp = __this_cpu_ptr(rsp->rda);



	atomic_inc(&rcu_barrier_cpu_count);

	rsp->call(head, rcu_barrier_callback);

	rsp->call(&rdp->barrier_head, rcu_barrier_callback);

}



/*

kernel/rcutree.h

+3 −0
Original line number Diff line number Diff line
@@ -314,6 +314,9 @@ struct rcu_data { 
	unsigned long n_rp_need_fqs;

	unsigned long n_rp_need_nothing;



	/* 6) _rcu_barrier() callback. */

	struct rcu_head barrier_head;



	int cpu;

	struct rcu_state *rsp;

};