rcu classic: simplify the next pending batch
use a batch number(rcp->pending) instead of a flag(rcp->next_pending)
rcu_start_batch() need to change this flag, so mb()s is needed
for memory-access safe.
but(after this patch applied) rcu_start_batch() do not change
this batch number(rcp->pending), rcp->pending is managed by
__rcu_process_callbacks only, and troublesome mb()s are eliminated.
And codes look simpler and clearer.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: Gautham Shenoy <ego@in.ibm.com>
Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/rcuclassic.h b/include/linux/rcuclassic.h
index 8c77490..c847e59 100644
--- a/include/linux/rcuclassic.h
+++ b/include/linux/rcuclassic.h
@@ -45,7 +45,7 @@
struct rcu_ctrlblk {
long cur; /* Current batch number. */
long completed; /* Number of the last completed batch */
- int next_pending; /* Is the next batch already waiting? */
+ long pending; /* Number of the last pending batch */
int signaled;