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rcu: Remove rcu_data_p pointer to default rcu_data structure 

The rcu_data_p pointer references the default set of per-CPU rcu_data
structures, that is, those that call_rcu() uses, as opposed to
call_rcu_bh() and sometimes call_rcu_sched().  But there is now only one
set of per-CPU rcu_data structures, so that one set is by definition
the default, which means that the rcu_data_p pointer no longer serves
any useful purpose.  This commit therefore removes it.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit is contained in:
Paul E. McKenney 2018-07-03 15:54:39 -07:00
parent 16fc9c600b
commit 2280ee5a7d
2 changed files with 5 additions and 6 deletions
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1
kernel/rcu/tree.c
View File

@ -85,7 +85,6 @@ struct rcu_state rcu_state = {
.ofl_lock = __SPIN_LOCK_UNLOCKED(rcu_state.ofl_lock),
};
static struct rcu_data __percpu *const rcu_data_p = &rcu_data;
LIST_HEAD(rcu_struct_flavors);
/* Dump rcu_node combining tree at boot to verify correct setup. */

10
kernel/rcu/tree_plugin.h
View File

@ -302,11 +302,11 @@ static void rcu_preempt_ctxt_queue(struct rcu_node *rnp, struct rcu_data *rdp)
static void rcu_qs(void)
{
RCU_LOCKDEP_WARN(preemptible(), "rcu_qs() invoked with preemption enabled!!!\n");
if (__this_cpu_read(rcu_data_p->cpu_no_qs.s)) {
if (__this_cpu_read(rcu_data.cpu_no_qs.s)) {
trace_rcu_grace_period(TPS("rcu_preempt"),
__this_cpu_read(rcu_data_p->gp_seq),
__this_cpu_read(rcu_data.gp_seq),
TPS("cpuqs"));
__this_cpu_write(rcu_data_p->cpu_no_qs.b.norm, false);
__this_cpu_write(rcu_data.cpu_no_qs.b.norm, false);
barrier(); /* Coordinate with rcu_flavor_check_callbacks(). */
current->rcu_read_unlock_special.b.need_qs = false;
}
@ -805,8 +805,8 @@ static void rcu_flavor_check_callbacks(int user)
/* If GP is oldish, ask for help from rcu_read_unlock_special(). */
if (t->rcu_read_lock_nesting > 0 &&
__this_cpu_read(rcu_data_p->core_needs_qs) &&
__this_cpu_read(rcu_data_p->cpu_no_qs.b.norm) &&
__this_cpu_read(rcu_data.core_needs_qs) &&
__this_cpu_read(rcu_data.cpu_no_qs.b.norm) &&
!t->rcu_read_unlock_special.b.need_qs &&
time_after(jiffies, rsp->gp_start + HZ))
t->rcu_read_unlock_special.b.need_qs = true;