rcu/nocb: Use separate flag to indicate offloaded ->cblist

RCU callback processing currently uses rcu_is_nocb_cpu() to determine
whether or not the current CPU's callbacks are to be offloaded.
This works, but it is not so good for cache locality.  Plus use of
->cblist for offloaded callbacks will greatly increase the frequency
of these checks.  This commit therefore adds a ->offloaded flag to the
rcu_segcblist structure to provide a more flexible and cache-friendly
means of checking for callback offloading.

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/rcu_segcblist.h b/include/linux/rcu_segcblist.h
index ed2cfd3c0743..8b684888f71d 100644
--- a/include/linux/rcu_segcblist.h
+++ b/include/linux/rcu_segcblist.h
@@ -71,6 +71,7 @@ struct rcu_segcblist {
 	long len;
 	long len_lazy;
 	u8 enabled;
+	u8 offloaded;
 };
 
 #define RCU_SEGCBLIST_INITIALIZER(n) \