rcu: Create an immutable rcu_data_p pointer to default rcu_data structure

This commit creates an immutable rcu_data_p pointer that references
rcu_preempt_data for TREE_PREEMPT_RCU builds and that references
rcu_sched_data for TREE_RCU builds.  This rcu_data_p pointer will enable
more code to move from #ifdef to IS_ENABLED().

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit is contained in:
Paul E. McKenney 2015-03-04 07:53:04 -08:00
parent b28a7c0166
commit 2927a689e8
2 changed files with 10 additions and 7 deletions

View File

@ -111,6 +111,7 @@ RCU_STATE_INITIALIZER(rcu_sched, 's', call_rcu_sched);
RCU_STATE_INITIALIZER(rcu_bh, 'b', call_rcu_bh);
static struct rcu_state *const rcu_state_p;
static struct rcu_data __percpu *const rcu_data_p;
LIST_HEAD(rcu_struct_flavors);
/* Increase (but not decrease) the CONFIG_RCU_FANOUT_LEAF at boot time. */

View File

@ -101,6 +101,7 @@ static void __init rcu_bootup_announce_oddness(void)
RCU_STATE_INITIALIZER(rcu_preempt, 'p', call_rcu);
static struct rcu_state *const rcu_state_p = &rcu_preempt_state;
static struct rcu_data __percpu *const rcu_data_p = &rcu_preempt_data;
static int rcu_preempted_readers_exp(struct rcu_node *rnp);
static void rcu_report_exp_rnp(struct rcu_state *rsp, struct rcu_node *rnp,
@ -126,11 +127,11 @@ static void __init rcu_bootup_announce(void)
*/
static void rcu_preempt_qs(void)
{
if (!__this_cpu_read(rcu_preempt_data.passed_quiesce)) {
if (!__this_cpu_read(rcu_data_p->passed_quiesce)) {
trace_rcu_grace_period(TPS("rcu_preempt"),
__this_cpu_read(rcu_preempt_data.gpnum),
__this_cpu_read(rcu_data_p->gpnum),
TPS("cpuqs"));
__this_cpu_write(rcu_preempt_data.passed_quiesce, 1);
__this_cpu_write(rcu_data_p->passed_quiesce, 1);
barrier(); /* Coordinate with rcu_preempt_check_callbacks(). */
current->rcu_read_unlock_special.b.need_qs = false;
}
@ -495,8 +496,8 @@ static void rcu_preempt_check_callbacks(void)
return;
}
if (t->rcu_read_lock_nesting > 0 &&
__this_cpu_read(rcu_preempt_data.qs_pending) &&
!__this_cpu_read(rcu_preempt_data.passed_quiesce))
__this_cpu_read(rcu_data_p->qs_pending) &&
!__this_cpu_read(rcu_data_p->passed_quiesce))
t->rcu_read_unlock_special.b.need_qs = true;
}
@ -504,7 +505,7 @@ static void rcu_preempt_check_callbacks(void)
static void rcu_preempt_do_callbacks(void)
{
rcu_do_batch(rcu_state_p, this_cpu_ptr(&rcu_preempt_data));
rcu_do_batch(rcu_state_p, this_cpu_ptr(rcu_data_p));
}
#endif /* #ifdef CONFIG_RCU_BOOST */
@ -811,7 +812,7 @@ EXPORT_SYMBOL_GPL(rcu_barrier);
*/
static void __init __rcu_init_preempt(void)
{
rcu_init_one(rcu_state_p, &rcu_preempt_data);
rcu_init_one(rcu_state_p, rcu_data_p);
}
/*
@ -835,6 +836,7 @@ void exit_rcu(void)
#else /* #ifdef CONFIG_PREEMPT_RCU */
static struct rcu_state *const rcu_state_p = &rcu_sched_state;
static struct rcu_data __percpu *const rcu_data_p = &rcu_sched_data;
/*
* Tell them what RCU they are running.