diff options
Diffstat (limited to 'include/linux/hrtimer.h')
| -rw-r--r-- | include/linux/hrtimer.h | 97 |
1 files changed, 26 insertions, 71 deletions
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index 88e078871158..9ced498fefaa 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -2,7 +2,7 @@ /* * hrtimers - High-resolution kernel timers * - * Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de> + * Copyright(C) 2005, Linutronix GmbH, Thomas Gleixner <tglx@kernel.org> * Copyright(C) 2005, Red Hat, Inc., Ingo Molnar * * data type definitions, declarations, prototypes @@ -13,6 +13,7 @@ #define _LINUX_HRTIMER_H #include <linux/hrtimer_defs.h> +#include <linux/hrtimer_rearm.h> #include <linux/hrtimer_types.h> #include <linux/init.h> #include <linux/list.h> @@ -31,6 +32,13 @@ * soft irq context * HRTIMER_MODE_HARD - Timer callback function will be executed in * hard irq context even on PREEMPT_RT. + * HRTIMER_MODE_LAZY_REARM - Avoid reprogramming if the timer was the + * first expiring timer and is moved into the + * future. Special mode for the HRTICK timer to + * avoid extensive reprogramming of the hardware, + * which is expensive in virtual machines. Risks + * a pointless expiry, but that's better than + * reprogramming on every context switch, */ enum hrtimer_mode { HRTIMER_MODE_ABS = 0x00, @@ -38,6 +46,7 @@ enum hrtimer_mode { HRTIMER_MODE_PINNED = 0x02, HRTIMER_MODE_SOFT = 0x04, HRTIMER_MODE_HARD = 0x08, + HRTIMER_MODE_LAZY_REARM = 0x10, HRTIMER_MODE_ABS_PINNED = HRTIMER_MODE_ABS | HRTIMER_MODE_PINNED, HRTIMER_MODE_REL_PINNED = HRTIMER_MODE_REL | HRTIMER_MODE_PINNED, @@ -55,33 +64,6 @@ enum hrtimer_mode { HRTIMER_MODE_REL_PINNED_HARD = HRTIMER_MODE_REL_PINNED | HRTIMER_MODE_HARD, }; -/* - * Values to track state of the timer - * - * Possible states: - * - * 0x00 inactive - * 0x01 enqueued into rbtree - * - * The callback state is not part of the timer->state because clearing it would - * mean touching the timer after the callback, this makes it impossible to free - * the timer from the callback function. - * - * Therefore we track the callback state in: - * - * timer->base->cpu_base->running == timer - * - * On SMP it is possible to have a "callback function running and enqueued" - * status. It happens for example when a posix timer expired and the callback - * queued a signal. Between dropping the lock which protects the posix timer - * and reacquiring the base lock of the hrtimer, another CPU can deliver the - * signal and rearm the timer. - * - * All state transitions are protected by cpu_base->lock. - */ -#define HRTIMER_STATE_INACTIVE 0x00 -#define HRTIMER_STATE_ENQUEUED 0x01 - /** * struct hrtimer_sleeper - simple sleeper structure * @timer: embedded timer structure @@ -112,12 +94,6 @@ static inline void hrtimer_set_expires_range_ns(struct hrtimer *timer, ktime_t t timer->node.expires = ktime_add_safe(time, ns_to_ktime(delta)); } -static inline void hrtimer_set_expires_tv64(struct hrtimer *timer, s64 tv64) -{ - timer->node.expires = tv64; - timer->_softexpires = tv64; -} - static inline void hrtimer_add_expires(struct hrtimer *timer, ktime_t time) { timer->node.expires = ktime_add_safe(timer->node.expires, time); @@ -140,48 +116,30 @@ static inline ktime_t hrtimer_get_softexpires(const struct hrtimer *timer) return timer->_softexpires; } -static inline s64 hrtimer_get_expires_tv64(const struct hrtimer *timer) -{ - return timer->node.expires; -} -static inline s64 hrtimer_get_softexpires_tv64(const struct hrtimer *timer) -{ - return timer->_softexpires; -} - -static inline s64 hrtimer_get_expires_ns(const struct hrtimer *timer) -{ - return ktime_to_ns(timer->node.expires); -} +ktime_t hrtimer_cb_get_time(const struct hrtimer *timer); static inline ktime_t hrtimer_expires_remaining(const struct hrtimer *timer) { - return ktime_sub(timer->node.expires, timer->base->get_time()); -} - -static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer) -{ - return timer->base->get_time(); -} - -static inline int hrtimer_is_hres_active(struct hrtimer *timer) -{ - return IS_ENABLED(CONFIG_HIGH_RES_TIMERS) ? - timer->base->cpu_base->hres_active : 0; + return ktime_sub(timer->node.expires, hrtimer_cb_get_time(timer)); } #ifdef CONFIG_HIGH_RES_TIMERS +extern unsigned int hrtimer_resolution; struct clock_event_device; extern void hrtimer_interrupt(struct clock_event_device *dev); -extern unsigned int hrtimer_resolution; +extern struct static_key_false hrtimer_highres_enabled_key; -#else +static inline bool hrtimer_highres_enabled(void) +{ + return static_branch_likely(&hrtimer_highres_enabled_key); +} +#else /* CONFIG_HIGH_RES_TIMERS */ #define hrtimer_resolution (unsigned int)LOW_RES_NSEC - -#endif +static inline bool hrtimer_highres_enabled(void) { return false; } +#endif /* !CONFIG_HIGH_RES_TIMERS */ static inline ktime_t __hrtimer_expires_remaining_adjusted(const struct hrtimer *timer, ktime_t now) @@ -200,8 +158,7 @@ __hrtimer_expires_remaining_adjusted(const struct hrtimer *timer, ktime_t now) static inline ktime_t hrtimer_expires_remaining_adjusted(const struct hrtimer *timer) { - return __hrtimer_expires_remaining_adjusted(timer, - timer->base->get_time()); + return __hrtimer_expires_remaining_adjusted(timer, hrtimer_cb_get_time(timer)); } #ifdef CONFIG_TIMERFD @@ -231,8 +188,6 @@ static inline enum hrtimer_restart hrtimer_dummy_timeout(struct hrtimer *unused) /* Exported timer functions: */ /* Initialize timers: */ -extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock, - enum hrtimer_mode mode); extern void hrtimer_setup(struct hrtimer *timer, enum hrtimer_restart (*function)(struct hrtimer *), clockid_t clock_id, enum hrtimer_mode mode); extern void hrtimer_setup_on_stack(struct hrtimer *timer, @@ -314,8 +269,8 @@ extern bool hrtimer_active(const struct hrtimer *timer); */ static inline bool hrtimer_is_queued(struct hrtimer *timer) { - /* The READ_ONCE pairs with the update functions of timer->state */ - return !!(READ_ONCE(timer->state) & HRTIMER_STATE_ENQUEUED); + /* The READ_ONCE pairs with the update functions of timer->is_queued */ + return READ_ONCE(timer->is_queued); } /* @@ -347,7 +302,7 @@ static inline void hrtimer_update_function(struct hrtimer *timer, if (WARN_ON_ONCE(!function)) return; #endif - timer->function = function; + ACCESS_PRIVATE(timer, function) = function; } /* Forward a hrtimer so it expires after now: */ @@ -365,7 +320,7 @@ hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval); static inline u64 hrtimer_forward_now(struct hrtimer *timer, ktime_t interval) { - return hrtimer_forward(timer, timer->base->get_time(), interval); + return hrtimer_forward(timer, hrtimer_cb_get_time(timer), interval); } /* Precise sleep: */ |