Messages in this thread Patch in this message | | | Date | Tue, 18 Apr 2017 13:11:09 +0200 | From | Thomas Gleixner <> | Subject | [patch V2 07/10] tick/sched: Split out jiffies update helper function |
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The logic to get the time of the last jiffies update will be needed by the timer pull model as well.
Move the code into a global funtion in anticipation of the new caller.
No functional change.
Signed-off-by: Richard Cochran <rcochran@linutronix.de> Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
--- kernel/time/tick-internal.h | 1 + kernel/time/tick-sched.c | 27 ++++++++++++++++++++------- 2 files changed, 21 insertions(+), 7 deletions(-)
--- a/kernel/time/tick-internal.h +++ b/kernel/time/tick-internal.h @@ -151,6 +151,7 @@ static inline void tick_nohz_init(void) #ifdef CONFIG_NO_HZ_COMMON extern unsigned long tick_nohz_active; +extern u64 get_jiffies_update(unsigned long *basej); #else #define tick_nohz_active (0) #endif --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -112,6 +112,24 @@ static ktime_t tick_init_jiffy_update(vo return period; } +#ifdef CONFIG_NO_HZ_COMMON +/* + * Read jiffies and the time when jiffies were updated last + */ +u64 get_jiffies_update(unsigned long *basej) +{ + unsigned long seq, basejiff; + u64 basemono; + + do { + seq = read_seqbegin(&jiffies_lock); + basemono = last_jiffies_update; + basejiff = jiffies; + } while (read_seqretry(&jiffies_lock, seq)); + *basej = basejiff; + return basemono; +} +#endif static void tick_sched_do_timer(ktime_t now) { @@ -667,15 +685,10 @@ static ktime_t tick_nohz_stop_sched_tick { struct clock_event_device *dev = __this_cpu_read(tick_cpu_device.evtdev); u64 basemono, next_tick, next_local, next_global, next_rcu, delta, expires; - unsigned long seq, basejiff; + unsigned long basejiff; ktime_t tick; - /* Read jiffies and the time when jiffies were updated last */ - do { - seq = read_seqbegin(&jiffies_lock); - basemono = last_jiffies_update; - basejiff = jiffies; - } while (read_seqretry(&jiffies_lock, seq)); + basemono = get_jiffies_update(&basejiff); ts->last_jiffies = basejiff; if (rcu_needs_cpu(basemono, &next_rcu) ||
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