From 5dbe91de599423d243738a205367506444ebb4a4 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Wed, 1 Feb 2017 18:47:28 +0100 Subject: sched/headers: Move idle polling methods to Further reduce the size of by moving these APIs: tsk_is_polling() __current_set_polling() current_set_polling_and_test() __current_clr_polling() current_clr_polling_and_test() current_clr_polling() Acked-by: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar --- include/linux/sched/idle.h | 76 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 76 insertions(+) (limited to 'include/linux/sched/idle.h') diff --git a/include/linux/sched/idle.h b/include/linux/sched/idle.h index 72b6b6ab6354..66ee32f87f0b 100644 --- a/include/linux/sched/idle.h +++ b/include/linux/sched/idle.h @@ -12,4 +12,80 @@ enum cpu_idle_type { extern void wake_up_if_idle(int cpu); +/* + * Idle thread specific functions to determine the need_resched + * polling state. + */ +#ifdef TIF_POLLING_NRFLAG +static inline int tsk_is_polling(struct task_struct *p) +{ + return test_tsk_thread_flag(p, TIF_POLLING_NRFLAG); +} + +static inline void __current_set_polling(void) +{ + set_thread_flag(TIF_POLLING_NRFLAG); +} + +static inline bool __must_check current_set_polling_and_test(void) +{ + __current_set_polling(); + + /* + * Polling state must be visible before we test NEED_RESCHED, + * paired by resched_curr() + */ + smp_mb__after_atomic(); + + return unlikely(tif_need_resched()); +} + +static inline void __current_clr_polling(void) +{ + clear_thread_flag(TIF_POLLING_NRFLAG); +} + +static inline bool __must_check current_clr_polling_and_test(void) +{ + __current_clr_polling(); + + /* + * Polling state must be visible before we test NEED_RESCHED, + * paired by resched_curr() + */ + smp_mb__after_atomic(); + + return unlikely(tif_need_resched()); +} + +#else +static inline int tsk_is_polling(struct task_struct *p) { return 0; } +static inline void __current_set_polling(void) { } +static inline void __current_clr_polling(void) { } + +static inline bool __must_check current_set_polling_and_test(void) +{ + return unlikely(tif_need_resched()); +} +static inline bool __must_check current_clr_polling_and_test(void) +{ + return unlikely(tif_need_resched()); +} +#endif + +static inline void current_clr_polling(void) +{ + __current_clr_polling(); + + /* + * Ensure we check TIF_NEED_RESCHED after we clear the polling bit. + * Once the bit is cleared, we'll get IPIs with every new + * TIF_NEED_RESCHED and the IPI handler, scheduler_ipi(), will also + * fold. + */ + smp_mb(); /* paired with resched_curr() */ + + preempt_fold_need_resched(); +} + #endif /* _LINUX_SCHED_IDLE_H */ -- cgit v1.2.3