[PATCH tip/core/rcu 1/3] rcu: Expand SRCU ->completed to 64 bits

From: Paul E. McKenney
Date: Wed Jan 07 2015 - 12:39:22 EST


From: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx>

When rcutorture used only the low-order 32 bits of the grace-period
number, it was not a problem for SRCU to use a 32-bit completed field.
However, rcutorture now uses the full 64 bits on 64-bit systems, so
this commit converts SRCU's ->completed field to unsigned long so as to
provide 64 bits on 64-bit systems.

Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
---
include/linux/srcu.h | 4 ++--
kernel/rcu/srcu.c | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/linux/srcu.h b/include/linux/srcu.h
index a2783cb5d275..ef923dd96249 100644
--- a/include/linux/srcu.h
+++ b/include/linux/srcu.h
@@ -45,7 +45,7 @@ struct rcu_batch {
#define RCU_BATCH_INIT(name) { NULL, &(name.head) }

struct srcu_struct {
- unsigned completed;
+ unsigned long completed;
struct srcu_struct_array __percpu *per_cpu_ref;
spinlock_t queue_lock; /* protect ->batch_queue, ->running */
bool running;
@@ -135,7 +135,7 @@ int __srcu_read_lock(struct srcu_struct *sp) __acquires(sp);
void __srcu_read_unlock(struct srcu_struct *sp, int idx) __releases(sp);
void synchronize_srcu(struct srcu_struct *sp);
void synchronize_srcu_expedited(struct srcu_struct *sp);
-long srcu_batches_completed(struct srcu_struct *sp);
+unsigned long srcu_batches_completed(struct srcu_struct *sp);
void srcu_barrier(struct srcu_struct *sp);

#ifdef CONFIG_DEBUG_LOCK_ALLOC
diff --git a/kernel/rcu/srcu.c b/kernel/rcu/srcu.c
index e037f3eb2f7b..445bf8ffe3fb 100644
--- a/kernel/rcu/srcu.c
+++ b/kernel/rcu/srcu.c
@@ -546,7 +546,7 @@ EXPORT_SYMBOL_GPL(srcu_barrier);
* Report the number of batches, correlated with, but not necessarily
* precisely the same as, the number of grace periods that have elapsed.
*/
-long srcu_batches_completed(struct srcu_struct *sp)
+unsigned long srcu_batches_completed(struct srcu_struct *sp)
{
return sp->completed;
}
--
1.8.1.5

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