sched: convert nohz_cpu_mask to cpumask_var_t.
Impact: (future) size reduction for large NR_CPUS.
Dynamically allocating cpumasks (when CONFIG_CPUMASK_OFFSTACK) saves
space for small nr_cpu_ids but big CONFIG_NR_CPUS. cpumask_var_t
is just a struct cpumask for !CONFIG_CPUMASK_OFFSTACK.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/rcuclassic.c b/kernel/rcuclassic.c
index e503a00..c03ca3e 100644
--- a/kernel/rcuclassic.c
+++ b/kernel/rcuclassic.c
@@ -393,7 +393,7 @@
* unnecessarily.
*/
smp_mb();
- cpus_andnot(rcp->cpumask, cpu_online_map, nohz_cpu_mask);
+ cpumask_andnot(&rcp->cpumask, cpu_online_mask, nohz_cpu_mask);
rcp->signaled = 0;
}
diff --git a/kernel/sched.c b/kernel/sched.c
index 6b9606a..2723d7a 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -5870,9 +5870,9 @@
* indicates which cpus entered this state. This is used
* in the rcu update to wait only for active cpus. For system
* which do not switch off the HZ timer nohz_cpu_mask should
- * always be CPU_MASK_NONE.
+ * always be CPU_BITS_NONE.
*/
-cpumask_t nohz_cpu_mask = CPU_MASK_NONE;
+cpumask_var_t nohz_cpu_mask;
/*
* Increase the granularity value when there are more CPUs,
@@ -8274,6 +8274,9 @@
*/
current->sched_class = &fair_sched_class;
+ /* Allocate the nohz_cpu_mask if CONFIG_CPUMASK_OFFSTACK */
+ alloc_bootmem_cpumask_var(&nohz_cpu_mask);
+
scheduler_running = 1;
}
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 342fc9c..70f872c 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -144,7 +144,7 @@
if (!ts->tick_stopped)
return;
- cpu_clear(cpu, nohz_cpu_mask);
+ cpumask_clear_cpu(cpu, nohz_cpu_mask);
now = ktime_get();
ts->idle_waketime = now;
@@ -283,7 +283,7 @@
if ((long)delta_jiffies >= 1) {
if (delta_jiffies > 1)
- cpu_set(cpu, nohz_cpu_mask);
+ cpumask_set_cpu(cpu, nohz_cpu_mask);
/*
* nohz_stop_sched_tick can be called several times before
* the nohz_restart_sched_tick is called. This happens when
@@ -296,7 +296,7 @@
/*
* sched tick not stopped!
*/
- cpu_clear(cpu, nohz_cpu_mask);
+ cpumask_clear_cpu(cpu, nohz_cpu_mask);
goto out;
}
@@ -354,7 +354,7 @@
* softirq.
*/
tick_do_update_jiffies64(ktime_get());
- cpu_clear(cpu, nohz_cpu_mask);
+ cpumask_clear_cpu(cpu, nohz_cpu_mask);
}
raise_softirq_irqoff(TIMER_SOFTIRQ);
out:
@@ -432,7 +432,7 @@
select_nohz_load_balancer(0);
now = ktime_get();
tick_do_update_jiffies64(now);
- cpu_clear(cpu, nohz_cpu_mask);
+ cpumask_clear_cpu(cpu, nohz_cpu_mask);
/*
* We stopped the tick in idle. Update process times would miss the