Commit 18390aea authored Apr 22, 2018 by Paul E. McKenney

rcu: Make rcu_gp_cleanup() write only once to ->gp_flags



At the end of rcu_gp_cleanup(), if another grace period is needed, but
not via rcu_accelerate_cbs(), the ->gp_flags field is written twice,
once when making the new grace-period request, and once when clearing
all other types of requests.  This commit therefore adds an else-clause
to avoid this double write.

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

parent 26d950a9

kernel/rcu/tree.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -2117,8 +2117,9 @@ static void rcu_gp_cleanup(struct rcu_state *rsp)
		rsp->gp_req_activity = jiffies;
		trace_rcu_grace_period(rsp->name, READ_ONCE(rsp->gpnum),
		TPS("newreq"));
		}
		} else {
		WRITE_ONCE(rsp->gp_flags, rsp->gp_flags & RCU_GP_FLAG_INIT);
		}
		raw_spin_unlock_irq_rcu_node(rnp);
		}