From 1331e7a1bbe1f11b19c4327ba0853bee2a606543 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Thu, 2 Aug 2012 17:43:50 -0700 Subject: rcu: Remove _rcu_barrier() dependency on __stop_machine() Currently, _rcu_barrier() relies on preempt_disable() to prevent any CPU from going offline, which in turn depends on CPU hotplug's use of __stop_machine(). This patch therefore makes _rcu_barrier() use get_online_cpus() to block CPU-hotplug operations. This has the added benefit of removing the need for _rcu_barrier() to adopt callbacks: Because CPU-hotplug operations are excluded, there can be no callbacks to adopt. This commit simplifies the code accordingly. Signed-off-by: Paul E. McKenney Signed-off-by: Paul E. McKenney Reviewed-by: Josh Triplett --- kernel/rcutree.h | 3 --- 1 file changed, 3 deletions(-) (limited to 'kernel/rcutree.h') diff --git a/kernel/rcutree.h b/kernel/rcutree.h index 4d29169f2124..94dfdf1f31f5 100644 --- a/kernel/rcutree.h +++ b/kernel/rcutree.h @@ -398,9 +398,6 @@ struct rcu_state { struct rcu_head **orphan_donetail; /* Tail of above. */ long qlen_lazy; /* Number of lazy callbacks. */ long qlen; /* Total number of callbacks. */ - struct task_struct *rcu_barrier_in_progress; - /* Task doing rcu_barrier(), */ - /* or NULL if no barrier. */ struct mutex barrier_mutex; /* Guards barrier fields. */ atomic_t barrier_cpu_count; /* # CPUs waiting on. */ struct completion barrier_completion; /* Wake at barrier end. */ -- cgit v1.2.3-59-g8ed1b