From: Anna-Maria Gleixner Date: Wed, 20 Dec 2017 17:13:02 +0100 Subject: [PATCH 13/29] hrtimer: Reduce conditional code (hres_active) Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.14/older/patches-4.14.15-rt11.tar.xz The hrtimer_cpu_base struct has the CONFIG_HIGH_RES_TIMERS conditional struct member hres_active. All related functions to this member are conditional as well. There is no functional change, when the hres_active member is unconditional with all related functions and is set to zero during initialization. The conditional code sections can be avoided by adding IS_ENABLED(HIGHRES) conditionals into common functions, which ensures dead code elimination. Suggested-by: Thomas Gleixner Signed-off-by: Anna-Maria Gleixner Signed-off-by: Sebastian Andrzej Siewior --- include/linux/hrtimer.h | 20 ++++++++------------ kernel/time/hrtimer.c | 31 +++++++++++++++---------------- 2 files changed, 23 insertions(+), 28 deletions(-) --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -161,8 +161,8 @@ enum hrtimer_base_type { * @cpu: cpu number * @active_bases: Bitfield to mark bases with active timers * @clock_was_set_seq: Sequence counter of clock was set events - * @in_hrtirq: hrtimer_interrupt() is currently executing * @hres_active: State of high resolution mode + * @in_hrtirq: hrtimer_interrupt() is currently executing * @hang_detected: The last hrtimer interrupt detected a hang * @expires_next: absolute time of the next event, is required for remote * hrtimer enqueue @@ -182,9 +182,9 @@ struct hrtimer_cpu_base { unsigned int cpu; unsigned int active_bases; unsigned int clock_was_set_seq; + unsigned int hres_active : 1; #ifdef CONFIG_HIGH_RES_TIMERS unsigned int in_hrtirq : 1, - hres_active : 1, hang_detected : 1; ktime_t expires_next; struct hrtimer *next_timer; @@ -266,16 +266,17 @@ static inline ktime_t hrtimer_cb_get_tim 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; +} + #ifdef CONFIG_HIGH_RES_TIMERS struct clock_event_device; extern void hrtimer_interrupt(struct clock_event_device *dev); -static inline int hrtimer_is_hres_active(struct hrtimer *timer) -{ - return timer->base->cpu_base->hres_active; -} - /* * The resolution of the clocks. The resolution value is returned in * the clock_getres() system call to give application programmers an @@ -298,11 +299,6 @@ extern unsigned int hrtimer_resolution; #define hrtimer_resolution (unsigned int)LOW_RES_NSEC -static inline int hrtimer_is_hres_active(struct hrtimer *timer) -{ - return 0; -} - static inline void clock_was_set_delayed(void) { } #endif --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -512,6 +512,20 @@ static inline ktime_t hrtimer_update_bas offs_real, offs_boot, offs_tai); } +/* + * Is the high resolution mode active ? + */ +static inline int __hrtimer_hres_active(struct hrtimer_cpu_base *cpu_base) +{ + return IS_ENABLED(CONFIG_HIGH_RES_TIMERS) ? + cpu_base->hres_active : 0; +} + +static inline int hrtimer_hres_active(void) +{ + return __hrtimer_hres_active(this_cpu_ptr(&hrtimer_bases)); +} + /* High resolution timer related functions */ #ifdef CONFIG_HIGH_RES_TIMERS @@ -541,19 +555,6 @@ static inline int hrtimer_is_hres_enable } /* - * Is the high resolution mode active ? - */ -static inline int __hrtimer_hres_active(struct hrtimer_cpu_base *cpu_base) -{ - return cpu_base->hres_active; -} - -static inline int hrtimer_hres_active(void) -{ - return __hrtimer_hres_active(this_cpu_ptr(&hrtimer_bases)); -} - -/* * Reprogram the event source with checking both queues for the * next event * Called with interrupts disabled and base->lock held @@ -661,7 +662,6 @@ static void hrtimer_reprogram(struct hrt static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base) { base->expires_next = KTIME_MAX; - base->hres_active = 0; } /* @@ -720,8 +720,6 @@ void clock_was_set_delayed(void) #else -static inline int __hrtimer_hres_active(struct hrtimer_cpu_base *b) { return 0; } -static inline int hrtimer_hres_active(void) { return 0; } static inline int hrtimer_is_hres_enabled(void) { return 0; } static inline void hrtimer_switch_to_hres(void) { } static inline void @@ -1602,6 +1600,7 @@ int hrtimers_prepare_cpu(unsigned int cp } cpu_base->cpu = cpu; + cpu_base->hres_active = 0; hrtimer_init_hres(cpu_base); return 0; }