rcu: Eliminate redundant rcu_sysidle_state variable

Now that we have rcu_state_p, which references rcu_preempt_state for
TREE_PREEMPT_RCU and rcu_sched_state for TREE_RCU, we don't need a
separate rcu_sysidle_state variable.  This commit therefore eliminates
rcu_preempt_state in favor of rcu_state_p.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Tested-by: Paul Gortmaker <paul.gortmaker@windriver.com>
This commit is contained in:
Paul E. McKenney 2014-07-21 11:26:54 -07:00
parent 22c2f66961
commit 417e8d2655

View File

@ -2690,16 +2690,6 @@ static void __maybe_unused rcu_kick_nohz_cpu(int cpu)
#ifdef CONFIG_NO_HZ_FULL_SYSIDLE
/*
* Define RCU flavor that holds sysidle state. This needs to be the
* most active flavor of RCU.
*/
#ifdef CONFIG_PREEMPT_RCU
static struct rcu_state *rcu_sysidle_state = &rcu_preempt_state;
#else /* #ifdef CONFIG_PREEMPT_RCU */
static struct rcu_state *rcu_sysidle_state = &rcu_sched_state;
#endif /* #else #ifdef CONFIG_PREEMPT_RCU */
static int full_sysidle_state; /* Current system-idle state. */
#define RCU_SYSIDLE_NOT 0 /* Some CPU is not idle. */
#define RCU_SYSIDLE_SHORT 1 /* All CPUs idle for brief period. */
@ -2841,7 +2831,7 @@ static void rcu_sysidle_check_cpu(struct rcu_data *rdp, bool *isidle,
* not the flavor of RCU that tracks sysidle state, or if this
* is an offline or the timekeeping CPU, nothing to do.
*/
if (!*isidle || rdp->rsp != rcu_sysidle_state ||
if (!*isidle || rdp->rsp != rcu_state_p ||
cpu_is_offline(rdp->cpu) || rdp->cpu == tick_do_timer_cpu)
return;
if (rcu_gp_in_progress(rdp->rsp))
@ -2867,7 +2857,7 @@ static void rcu_sysidle_check_cpu(struct rcu_data *rdp, bool *isidle,
*/
static bool is_sysidle_rcu_state(struct rcu_state *rsp)
{
return rsp == rcu_sysidle_state;
return rsp == rcu_state_p;
}
/*
@ -2945,7 +2935,7 @@ static void rcu_sysidle_cancel(void)
static void rcu_sysidle_report(struct rcu_state *rsp, int isidle,
unsigned long maxj, bool gpkt)
{
if (rsp != rcu_sysidle_state)
if (rsp != rcu_state_p)
return; /* Wrong flavor, ignore. */
if (gpkt && nr_cpu_ids <= CONFIG_NO_HZ_FULL_SYSIDLE_SMALL)
return; /* Running state machine from timekeeping CPU. */
@ -3014,13 +3004,12 @@ bool rcu_sys_is_idle(void)
/* Scan all the CPUs looking for nonidle CPUs. */
for_each_possible_cpu(cpu) {
rdp = per_cpu_ptr(rcu_sysidle_state->rda, cpu);
rdp = per_cpu_ptr(rcu_state_p->rda, cpu);
rcu_sysidle_check_cpu(rdp, &isidle, &maxj);
if (!isidle)
break;
}
rcu_sysidle_report(rcu_sysidle_state,
isidle, maxj, false);
rcu_sysidle_report(rcu_state_p, isidle, maxj, false);
oldrss = rss;
rss = ACCESS_ONCE(full_sysidle_state);
}
@ -3047,7 +3036,7 @@ bool rcu_sys_is_idle(void)
* provided by the memory allocator.
*/
if (nr_cpu_ids > CONFIG_NO_HZ_FULL_SYSIDLE_SMALL &&
!rcu_gp_in_progress(rcu_sysidle_state) &&
!rcu_gp_in_progress(rcu_state_p) &&
!rsh.inuse && xchg(&rsh.inuse, 1) == 0)
call_rcu(&rsh.rh, rcu_sysidle_cb);
return false;