nohz: Optimize full dynticks state checks with static keys
These APIs are frequenctly accessed and priority is given
to optimize the full dynticks off-case in order to let
distros enable this feature without suffering from
significant performance regressions.
Let's inline these APIs and optimize them with static keys.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Kevin Hilman <khilman@linaro.org>
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index b28dee4..0b78873 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -149,7 +149,7 @@
}
#ifdef CONFIG_NO_HZ_FULL
-static cpumask_var_t tick_nohz_full_mask;
+cpumask_var_t tick_nohz_full_mask;
bool tick_nohz_full_running;
static bool can_stop_full_tick(void)
@@ -270,14 +270,6 @@
local_irq_restore(flags);
}
-int tick_nohz_full_cpu(int cpu)
-{
- if (!tick_nohz_full_running)
- return 0;
-
- return cpumask_test_cpu(cpu, tick_nohz_full_mask);
-}
-
/* Parse the boot-time nohz CPU list from the kernel parameters. */
static int __init tick_nohz_full_setup(char *str)
{
@@ -359,8 +351,6 @@
cpulist_scnprintf(nohz_full_buf, sizeof(nohz_full_buf), tick_nohz_full_mask);
pr_info("NO_HZ: Full dynticks CPUs: %s.\n", nohz_full_buf);
}
-#else
-#define tick_nohz_full_running (0)
#endif
/*
@@ -738,7 +728,7 @@
return false;
}
- if (tick_nohz_full_running) {
+ if (tick_nohz_full_enabled()) {
/*
* Keep the tick alive to guarantee timekeeping progression
* if there are full dynticks CPUs around