From b0f740360efec6e6471547c0548f250bc045a233 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 4 Feb 2013 12:14:24 -0800 Subject: [PATCH] rcu: Avoid invoking RCU core on offline CPUs Offline CPUs transition through the scheduler to the idle loop one last time before being shut down. This can result in RCU raising softirq on this CPU, which is at best useless given that the CPU's callbacks will be offloaded at CPU_DEAD time. This commit therefore avoids raising softirq on offline CPUs. Signed-off-by: Paul E. McKenney --- kernel/rcutree.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 157539a975df..b2fc234ba1b9 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -2169,7 +2169,8 @@ static void invoke_rcu_callbacks(struct rcu_state *rsp, struct rcu_data *rdp) static void invoke_rcu_core(void) { - raise_softirq(RCU_SOFTIRQ); + if (cpu_online(smp_processor_id())) + raise_softirq(RCU_SOFTIRQ); } /* -- 2.20.1