nohz: Remove nohz_cpu_mask

RCU no longer uses this global variable, nor does anyone else.  This
commit therefore removes this variable.  This reduces memory footprint
and also removes some atomic instructions and memory barriers from
the dyntick-idle path.

Signed-off-by: Alex Shi <alex.shi@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

1 files changed, 0 insertions, 6 deletions

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index d5097c44b407..eb98e55196b9 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -139,7 +139,6 @@ static void tick_nohz_update_jiffies(ktime_t now)
         struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
         unsigned long flags;
 
-        cpumask_clear_cpu(cpu, nohz_cpu_mask);
         ts->idle_waketime = now;
 
         local_irq_save(flags);
@@ -389,9 +388,6 @@ void tick_nohz_stop_sched_tick(int inidle)
                 else
                         expires.tv64 = KTIME_MAX;
 
-                if (delta_jiffies > 1)
-                        cpumask_set_cpu(cpu, nohz_cpu_mask);
-
                 /* Skip reprogram of event if its not changed */
                 if (ts->tick_stopped && ktime_equal(expires, dev->next_event))
                         goto out;
@@ -441,7 +437,6 @@ void tick_nohz_stop_sched_tick(int inidle)
                  * softirq.
                  */
                 tick_do_update_jiffies64(ktime_get());
-                cpumask_clear_cpu(cpu, nohz_cpu_mask);
         }
         raise_softirq_irqoff(TIMER_SOFTIRQ);
 out:
@@ -524,7 +519,6 @@ void tick_nohz_restart_sched_tick(void)
         /* Update jiffies first */
         select_nohz_load_balancer(0);
         tick_do_update_jiffies64(now);
-        cpumask_clear_cpu(cpu, nohz_cpu_mask);
 
 #ifndef CONFIG_VIRT_CPU_ACCOUNTING
         /*