nohz: New option to default all CPUs in full dynticks range

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / kernel / time / tick-sched.c

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index d71a5f2bd7b2d5dd50432421787bd83d12cf1c10..a76e09044f9f4a9b594f03a246eb61259719e827 100644 (file)
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -203,12 +203,31 @@ static int __cpuinit tick_nohz_cpu_down_callback(struct notifier_block *nfb,
  */
 static char __initdata nohz_full_buf[NR_CPUS + 1];
 
+static int tick_nohz_init_all(void)
+{
+       int err = -1;
+
+#ifdef CONFIG_NO_HZ_FULL_ALL
+       if (!alloc_cpumask_var(&nohz_full_mask, GFP_KERNEL)) {
+               pr_err("NO_HZ: Can't allocate full dynticks cpumask\n");
+               return err;
+       }
+       err = 0;
+       cpumask_setall(nohz_full_mask);
+       cpumask_clear_cpu(smp_processor_id(), nohz_full_mask);
+       have_nohz_full_mask = true;
+#endif
+       return err;
+}
+
 void __init tick_nohz_init(void)
 {
        int cpu;
 
-       if (!have_nohz_full_mask)
-               return;
+       if (!have_nohz_full_mask) {
+               if (tick_nohz_init_all() < 0)
+                       return;
+       }
 
        cpu_notifier(tick_nohz_cpu_down_callback, 0);