Commit-ID: 7197e77abcb65a71d0b21d67beb24f153a96055e Gitweb: https://git.kernel.org/tip/7197e77abcb65a71d0b21d67beb24f153a96055e Author: Peter Zijlstra <pet...@infradead.org> AuthorDate: Mon, 30 Apr 2018 12:00:15 +0200 Committer: Thomas Gleixner <t...@linutronix.de> CommitDate: Wed, 2 May 2018 16:11:46 +0200
clocksource: Remove kthread The clocksource watchdog uses a work to spawn a kthread to run the watchdog. That is about as silly as it sounds, run the watchdog directly from the work. Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Signed-off-by: Thomas Gleixner <t...@linutronix.de> Reviewed-by: Rafael J. Wysocki <rafael.j.wyso...@intel.com> Cc: len.br...@intel.com Cc: r...@rjwysocki.net Cc: diego.vi...@gmail.com Cc: rui.zh...@intel.com Link: https://lkml.kernel.org/r/20180430100344.713862...@infradead.org --- kernel/time/clocksource.c | 31 ++++++++++--------------------- 1 file changed, 10 insertions(+), 21 deletions(-) diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index 84f37420fcf5..56fd2239674f 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -129,31 +129,19 @@ static void inline clocksource_watchdog_unlock(unsigned long *flags) spin_unlock_irqrestore(&watchdog_lock, *flags); } -static int clocksource_watchdog_kthread(void *data); -static void __clocksource_change_rating(struct clocksource *cs, int rating); - /* * Interval: 0.5sec Threshold: 0.0625s */ #define WATCHDOG_INTERVAL (HZ >> 1) #define WATCHDOG_THRESHOLD (NSEC_PER_SEC >> 4) -static void clocksource_watchdog_work(struct work_struct *work) -{ - /* - * If kthread_run fails the next watchdog scan over the - * watchdog_list will find the unstable clock again. - */ - kthread_run(clocksource_watchdog_kthread, NULL, "kwatchdog"); -} - static void __clocksource_unstable(struct clocksource *cs) { cs->flags &= ~(CLOCK_SOURCE_VALID_FOR_HRES | CLOCK_SOURCE_WATCHDOG); cs->flags |= CLOCK_SOURCE_UNSTABLE; /* - * If the clocksource is registered clocksource_watchdog_kthread() will + * If the clocksource is registered clocksource_watchdog_work() will * re-rate and re-select. */ if (list_empty(&cs->list)) { @@ -164,7 +152,7 @@ static void __clocksource_unstable(struct clocksource *cs) if (cs->mark_unstable) cs->mark_unstable(cs); - /* kick clocksource_watchdog_kthread() */ + /* kick clocksource_watchdog_work() */ if (finished_booting) schedule_work(&watchdog_work); } @@ -174,7 +162,7 @@ static void __clocksource_unstable(struct clocksource *cs) * @cs: clocksource to be marked unstable * * This function is called by the x86 TSC code to mark clocksources as unstable; - * it defers demotion and re-selection to a kthread. + * it defers demotion and re-selection to a work. */ void clocksource_mark_unstable(struct clocksource *cs) { @@ -399,7 +387,9 @@ static void clocksource_dequeue_watchdog(struct clocksource *cs) } } -static int __clocksource_watchdog_kthread(void) +static void __clocksource_change_rating(struct clocksource *cs, int rating); + +static int __clocksource_watchdog_work(void) { struct clocksource *cs, *tmp; unsigned long flags; @@ -424,13 +414,12 @@ static int __clocksource_watchdog_kthread(void) return select; } -static int clocksource_watchdog_kthread(void *data) +static void clocksource_watchdog_work(struct work_struct *work) { mutex_lock(&clocksource_mutex); - if (__clocksource_watchdog_kthread()) + if (__clocksource_watchdog_work()) clocksource_select(); mutex_unlock(&clocksource_mutex); - return 0; } static bool clocksource_is_watchdog(struct clocksource *cs) @@ -449,7 +438,7 @@ static void clocksource_enqueue_watchdog(struct clocksource *cs) static void clocksource_select_watchdog(bool fallback) { } static inline void clocksource_dequeue_watchdog(struct clocksource *cs) { } static inline void clocksource_resume_watchdog(void) { } -static inline int __clocksource_watchdog_kthread(void) { return 0; } +static inline int __clocksource_watchdog_work(void) { return 0; } static bool clocksource_is_watchdog(struct clocksource *cs) { return false; } void clocksource_mark_unstable(struct clocksource *cs) { } @@ -683,7 +672,7 @@ static int __init clocksource_done_booting(void) /* * Run the watchdog first to eliminate unstable clock sources */ - __clocksource_watchdog_kthread(); + __clocksource_watchdog_work(); clocksource_select(); mutex_unlock(&clocksource_mutex); return 0;
