redonkable
/
alistair23-linux
1
0
Fork 0
Code Releases Activity

sched/nohz: Clean up select_nohz_load_balancer() 

There is no load_balancer to be selected now. It just sets the
state of the nohz tick to stop.

So rename the function, pass the 'cpu' as a parameter and then
remove the useless call from tick_nohz_restart_sched_tick().

[ s/set_nohz_tick_stopped/nohz_balance_enter_idle/g
  s/clear_nohz_tick_stopped/nohz_balance_exit_idle/g ]
Signed-off-by: Alex Shi <alex.shi@intel.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1347261059-24747-1-git-send-email-alex.shi@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
hifive-unleashed-5.1
Alex Shi 2012-09-10 15:10:58 +08:00 committed by Ingo Molnar
parent 08bedae1d0
commit c1cc017c59
3 changed files with 13 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
include/linux/sched.h
View File

@ -273,11 +273,11 @@ extern void init_idle_bootup_task(struct task_struct *idle);
extern int runqueue_is_locked(int cpu);
#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ)
extern void select_nohz_load_balancer(int stop_tick);
extern void nohz_balance_enter_idle(int cpu);
extern void set_cpu_sd_state_idle(void);
extern int get_nohz_timer_target(void);
#else
static inline void select_nohz_load_balancer(int stop_tick) { }
static inline void nohz_balance_enter_idle(int cpu) { }
static inline void set_cpu_sd_state_idle(void) { }
#endif

25
kernel/sched/fair.c
View File

@ -4603,7 +4603,7 @@ static void nohz_balancer_kick(int cpu)
return;
}
static inline void clear_nohz_tick_stopped(int cpu)
static inline void nohz_balance_exit_idle(int cpu)
{
if (unlikely(test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))) {
cpumask_clear_cpu(cpu, nohz.idle_cpus_mask);
@ -4643,28 +4643,23 @@ void set_cpu_sd_state_idle(void)
}
/*
* This routine will record that this cpu is going idle with tick stopped.
* This routine will record that the cpu is going idle with tick stopped.
* This info will be used in performing idle load balancing in the future.
*/
void select_nohz_load_balancer(int stop_tick)
void nohz_balance_enter_idle(int cpu)
{
int cpu = smp_processor_id();
/*
* If this cpu is going down, then nothing needs to be done.
*/
if (!cpu_active(cpu))
return;
if (stop_tick) {
if (test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))
return;
if (test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))
return;
cpumask_set_cpu(cpu, nohz.idle_cpus_mask);
atomic_inc(&nohz.nr_cpus);
set_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu));
}
return;
cpumask_set_cpu(cpu, nohz.idle_cpus_mask);
atomic_inc(&nohz.nr_cpus);
set_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu));
}
static int __cpuinit sched_ilb_notifier(struct notifier_block *nfb,
@ -4672,7 +4667,7 @@ static int __cpuinit sched_ilb_notifier(struct notifier_block *nfb,
{
switch (action & ~CPU_TASKS_FROZEN) {
case CPU_DYING:
clear_nohz_tick_stopped(smp_processor_id());
nohz_balance_exit_idle(smp_processor_id());
return NOTIFY_OK;
default:
return NOTIFY_DONE;
@ -4833,7 +4828,7 @@ static inline int nohz_kick_needed(struct rq *rq, int cpu)
* busy tick after returning from idle, we will update the busy stats.
*/
set_cpu_sd_state_busy();
clear_nohz_tick_stopped(cpu);
nohz_balance_exit_idle(cpu);
/*
* None are in tickless mode and hence no need for NOHZ idle load

3
kernel/time/tick-sched.c
View File

@ -372,7 +372,7 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
* the scheduler tick in nohz_restart_sched_tick.
*/
if (!ts->tick_stopped) {
select_nohz_load_balancer(1);
nohz_balance_enter_idle(cpu);
calc_load_enter_idle();
ts->last_tick = hrtimer_get_expires(&ts->sched_timer);
@ -569,7 +569,6 @@ static void tick_nohz_restart(struct tick_sched *ts, ktime_t now)
static void tick_nohz_restart_sched_tick(struct tick_sched *ts, ktime_t now)
{
/* Update jiffies first */
select_nohz_load_balancer(0);
tick_do_update_jiffies64(now);
update_cpu_load_nohz();