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author | Frederic Weisbecker <fweisbec@gmail.com> | 2013-07-24 23:52:27 +0200 |
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committer | Frederic Weisbecker <fweisbec@gmail.com> | 2013-08-14 17:14:57 +0200 |
commit | 460775df4680b4593d8449bc171008578625a850 (patch) | |
tree | 9b6adb04b9751c70c05bfa97761bd5f2a5c9d1aa /include/linux/tick.h | |
parent | 73867dcd0792ad14fb31bfe73d09d9a4576f7fc2 (diff) | |
download | linux-stable-460775df4680b4593d8449bc171008578625a850.tar.gz linux-stable-460775df4680b4593d8449bc171008578625a850.tar.bz2 linux-stable-460775df4680b4593d8449bc171008578625a850.zip |
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>
Diffstat (limited to 'include/linux/tick.h')
-rw-r--r-- | include/linux/tick.h | 25 |
1 files changed, 23 insertions, 2 deletions
diff --git a/include/linux/tick.h b/include/linux/tick.h index 9180f4b85e6d..c60b079e1b37 100644 --- a/include/linux/tick.h +++ b/include/linux/tick.h @@ -10,6 +10,8 @@ #include <linux/irqflags.h> #include <linux/percpu.h> #include <linux/hrtimer.h> +#include <linux/context_tracking_state.h> +#include <linux/cpumask.h> #ifdef CONFIG_GENERIC_CLOCKEVENTS @@ -158,15 +160,34 @@ static inline u64 get_cpu_iowait_time_us(int cpu, u64 *unused) { return -1; } # endif /* !CONFIG_NO_HZ_COMMON */ #ifdef CONFIG_NO_HZ_FULL +extern bool tick_nohz_full_running; +extern cpumask_var_t tick_nohz_full_mask; + +static inline bool tick_nohz_full_enabled(void) +{ + if (!static_key_false(&context_tracking_enabled)) + return false; + + return tick_nohz_full_running; +} + +static inline bool tick_nohz_full_cpu(int cpu) +{ + if (!tick_nohz_full_enabled()) + return false; + + return cpumask_test_cpu(cpu, tick_nohz_full_mask); +} + extern void tick_nohz_init(void); -extern int tick_nohz_full_cpu(int cpu); extern void tick_nohz_full_check(void); extern void tick_nohz_full_kick(void); extern void tick_nohz_full_kick_all(void); extern void tick_nohz_task_switch(struct task_struct *tsk); #else static inline void tick_nohz_init(void) { } -static inline int tick_nohz_full_cpu(int cpu) { return 0; } +static inline bool tick_nohz_full_enabled(void) { return false; } +static inline bool tick_nohz_full_cpu(int cpu) { return false; } static inline void tick_nohz_full_check(void) { } static inline void tick_nohz_full_kick(void) { } static inline void tick_nohz_full_kick_all(void) { } |