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rcu: Move rcu_barrier_completion to rcu_state structure

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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: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
This commit is contained in:
Paul E. McKenney 2012-05-29 03:03:37 -07:00 • committed by Paul E. McKenney
parent 24ebbca8ec
commit 7db74df88b
2 changed files with 5 additions and 5 deletions
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9
kernel/rcutree.c
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@ -158,7 +158,6 @@ unsigned long rcutorture_vernum;
/* State information for rcu_barrier() and friends. */ /* State information for rcu_barrier() and friends. */
static DEFINE_MUTEX(rcu_barrier_mutex); 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 * 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; struct rcu_state *rsp = rdp->rsp;
if (atomic_dec_and_test(&rsp->barrier_cpu_count)) 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 * 6. Both rcu_barrier_callback() callbacks are invoked, awakening
* us -- but before CPU 1's orphaned callbacks are invoked!!! * 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); atomic_set(&rsp->barrier_cpu_count, 1);
raw_spin_lock_irqsave(&rsp->onofflock, flags); raw_spin_lock_irqsave(&rsp->onofflock, flags);
rsp->rcu_barrier_in_progress = current; 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. * CPU, and thus each counted, remove the initial count.
*/ */
if (atomic_dec_and_test(&rsp->barrier_cpu_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 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. */ /* Other rcu_barrier() invocations can now safely proceed. */
mutex_unlock(&rcu_barrier_mutex); mutex_unlock(&rcu_barrier_mutex);

1
kernel/rcutree.h
View file

@ -401,6 +401,7 @@ struct rcu_state {
/* Task doing rcu_barrier(), */ /* Task doing rcu_barrier(), */
/* or NULL if no barrier. */ /* or NULL if no barrier. */
atomic_t barrier_cpu_count; /* # CPUs waiting on. */ atomic_t barrier_cpu_count; /* # CPUs waiting on. */
struct completion barrier_completion; /* Wake at barrier end. */
raw_spinlock_t fqslock; /* Only one task forcing */ raw_spinlock_t fqslock; /* Only one task forcing */
/* quiescent states. */ /* quiescent states. */
unsigned long jiffies_force_qs; /* Time at which to invoke */ unsigned long jiffies_force_qs; /* Time at which to invoke */