From eda669a6a2c517fd6db41d0fe3c95c1b749c60bd Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 1 Jul 2019 17:36:53 -0700 Subject: rcu/nocb: Atomic ->len field in rcu_segcblist structure Upcoming ->nocb_lock contention-reduction work requires that the rcu_segcblist structure's ->len field be concurrently manipulated, but only if there are no-CBs CPUs in the kernel. This commit therefore makes this ->len field be an atomic_long_t, but only in CONFIG_RCU_NOCB_CPU=y kernels. Signed-off-by: Paul E. McKenney --- include/linux/rcu_segcblist.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux') diff --git a/include/linux/rcu_segcblist.h b/include/linux/rcu_segcblist.h index 8b684888f71d..646759042333 100644 --- a/include/linux/rcu_segcblist.h +++ b/include/linux/rcu_segcblist.h @@ -68,7 +68,11 @@ struct rcu_segcblist { struct rcu_head *head; struct rcu_head **tails[RCU_CBLIST_NSEGS]; unsigned long gp_seq[RCU_CBLIST_NSEGS]; +#ifdef CONFIG_RCU_NOCB_CPU + atomic_long_t len; +#else long len; +#endif long len_lazy; u8 enabled; u8 offloaded; -- cgit v1.2.3