From: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Date: Wed, 21 Jan 2015 06:44:13 +0000 (-0800)
Subject: rcu: Wire ->rda pointers at compile time
X-Git-Tag: v4.1-rc1~145^2~2^2^2~5
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=2723249a31a68ccc0ec8ac59a905d7f9430bf8f6;p=karo-tx-linux.git

rcu: Wire ->rda pointers at compile time

This commit wires up the rcu_state structures' ->rda pointers to the
per-CPU rcu_data structures at compile time, thus ensuring that this
linkage is present at early boot, in turn allowing posting of callbacks
before rcu_init() is executed.

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

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index f8cdb92da10b..d2fa95e4a268 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -91,8 +91,10 @@ static const char *tp_##sname##_varname __used __tracepoint_string = sname##_var
 
 #define RCU_STATE_INITIALIZER(sname, sabbr, cr) \
 DEFINE_RCU_TPS(sname) \
+DEFINE_PER_CPU_SHARED_ALIGNED(struct rcu_data, sname##_data); \
 struct rcu_state sname##_state = { \
 	.level = { &sname##_state.node[0] }, \
+	.rda = &sname##_data, \
 	.call = cr, \
 	.fqs_state = RCU_GP_IDLE, \
 	.gpnum = 0UL - 300UL, \
@@ -104,8 +106,7 @@ struct rcu_state sname##_state = { \
 	.onoff_mutex = __MUTEX_INITIALIZER(sname##_state.onoff_mutex), \
 	.name = RCU_STATE_NAME(sname), \
 	.abbr = sabbr, \
-}; \
-DEFINE_PER_CPU_SHARED_ALIGNED(struct rcu_data, sname##_data)
+}
 
 RCU_STATE_INITIALIZER(rcu_sched, 's', call_rcu_sched);
 RCU_STATE_INITIALIZER(rcu_bh, 'b', call_rcu_bh);
@@ -3843,7 +3844,6 @@ static void __init rcu_init_one(struct rcu_state *rsp,
 		}
 	}
 
-	rsp->rda = rda;
 	init_waitqueue_head(&rsp->gp_wq);
 	rnp = rsp->level[rcu_num_lvls - 1];
 	for_each_possible_cpu(i) {