diff mbox

[tip/core/rcu,06/22] rcu: Move _rcu_barrier()'s rcu_head structures to rcu_data structures

Message ID 1340378241-6458-6-git-send-email-paulmck@linux.vnet.ibm.com
State Accepted
Commit 06668efa9180f4824fe846a8ff96338c18646bc7
Headers show

Commit Message

Paul E. McKenney June 22, 2012, 3:17 p.m. UTC 
From: "Paul E. McKenney" <paul.mckenney@linaro.org>

In order for multiple flavors of RCU to each concurrently run one
rcu_barrier(), each flavor needs its own per-CPU set of rcu_head
structures.  This commit therefore moves _rcu_barrier()'s set of
per-CPU rcu_head structures from per-CPU variables to the existing
per-CPU and per-RCU-flavor rcu_data structures.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
---
 kernel/rcutree.c |    6 ++----
 kernel/rcutree.h |    3 +++
 2 files changed, 5 insertions(+), 4 deletions(-)
diff mbox

Patch

diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 24cd2f0..cb2d35d 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -157,7 +157,6 @@  unsigned long rcutorture_vernum;
 
 /* State information for rcu_barrier() and friends. */
 
-static DEFINE_PER_CPU(struct rcu_head, rcu_barrier_head) = {NULL};
 static atomic_t rcu_barrier_cpu_count;
 static DEFINE_MUTEX(rcu_barrier_mutex);
 static struct completion rcu_barrier_completion;
@@ -2279,12 +2278,11 @@  static void rcu_barrier_callback(struct rcu_head *notused)
  */
 static void rcu_barrier_func(void *type)
 {
-	int cpu = smp_processor_id();
-	struct rcu_head *head = &per_cpu(rcu_barrier_head, cpu);
 	struct rcu_state *rsp = type;
+	struct rcu_data *rdp = __this_cpu_ptr(rsp->rda);
 
 	atomic_inc(&rcu_barrier_cpu_count);
-	rsp->call(head, rcu_barrier_callback);
+	rsp->call(&rdp->barrier_head, rcu_barrier_callback);
 }
 
 /*
diff --git a/kernel/rcutree.h b/kernel/rcutree.h
index 15837d7..1783eae 100644
--- a/kernel/rcutree.h
+++ b/kernel/rcutree.h
@@ -300,6 +300,9 @@  struct rcu_data {
 	unsigned long n_rp_need_fqs;
 	unsigned long n_rp_need_nothing;
 
+	/* 6) _rcu_barrier() callback. */
+	struct rcu_head barrier_head;
+
 	int cpu;
 	struct rcu_state *rsp;
 };