From 7809998ab1af22602a8463845108edc49dfb9ef0 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Mon, 25 Jan 2016 16:41:49 +0100 Subject: tick/sched: Hide unused oneshot timer code A couple of functions in kernel/time/tick-sched.c are only relevant for oneshot timer mode, i.e. when hires-timers or nohz mode are enabled. If both are disabled, we get gcc warnings about them: kernel/time/tick-sched.c:98:16: warning: 'tick_init_jiffy_update' defined but not used [-Wunused-function] static ktime_t tick_init_jiffy_update(void) ^ kernel/time/tick-sched.c:112:13: warning: 'tick_sched_do_timer' defined but not used [-Wunused-function] static void tick_sched_do_timer(ktime_t now) ^ kernel/time/tick-sched.c:134:13: warning: 'tick_sched_handle' defined but not used [-Wunused-function] static void tick_sched_handle(struct tick_sched *ts, struct pt_regs *regs) ^ This encloses the whole set of functions in an appropriate ifdef to avoid the warning and to make it clearer when they are used. Signed-off-by: Arnd Bergmann Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1453736525-1959191-1-git-send-email-arnd@arndb.de Signed-off-by: Thomas Gleixner --- kernel/time/tick-sched.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'kernel/time/tick-sched.c') diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 7ea28ed3109d..cbe5d8dcf15a 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -36,16 +36,17 @@ */ static DEFINE_PER_CPU(struct tick_sched, tick_cpu_sched); -/* - * The time, when the last jiffy update happened. Protected by jiffies_lock. - */ -static ktime_t last_jiffies_update; - struct tick_sched *tick_get_tick_sched(int cpu) { return &per_cpu(tick_cpu_sched, cpu); } +#if defined(CONFIG_NO_HZ_COMMON) || defined(CONFIG_HIGH_RES_TIMERS) +/* + * The time, when the last jiffy update happened. Protected by jiffies_lock. + */ +static ktime_t last_jiffies_update; + /* * Must be called with interrupts disabled ! */ @@ -151,6 +152,7 @@ static void tick_sched_handle(struct tick_sched *ts, struct pt_regs *regs) update_process_times(user_mode(regs)); profile_tick(CPU_PROFILING); } +#endif #ifdef CONFIG_NO_HZ_FULL cpumask_var_t tick_nohz_full_mask; -- cgit v1.2.3 From 1ca8ec532fc2d986f1f4a319857bb18e0c9739b4 Mon Sep 17 00:00:00 2001 From: Wanpeng Li Date: Wed, 27 Jan 2016 19:26:07 +0800 Subject: tick/nohz: Set the correct expiry when switching to nohz/lowres mode commit 0ff53d096422 sets the next tick interrupt to the last jiffies update, i.e. in the past, because the forward operation is invoked before the set operation. There is no resulting damage (yet), but we get an extra pointless tick interrupt. Revert the order so we get the next tick interrupt in the future. Fixes: commit 0ff53d096422 "tick: sched: Force tick interrupt and get rid of softirq magic" Signed-off-by: Wanpeng Li Cc: Peter Zijlstra Cc: Frederic Weisbecker Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1453893967-3458-1-git-send-email-wanpeng.li@hotmail.com Signed-off-by: Thomas Gleixner --- kernel/time/tick-sched.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel/time/tick-sched.c') diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index cbe5d8dcf15a..de2d9fef6ea6 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -995,9 +995,9 @@ static void tick_nohz_switch_to_nohz(void) /* Get the next period */ next = tick_init_jiffy_update(); - hrtimer_forward_now(&ts->sched_timer, tick_period); hrtimer_set_expires(&ts->sched_timer, next); - tick_program_event(next, 1); + hrtimer_forward_now(&ts->sched_timer, tick_period); + tick_program_event(hrtimer_get_expires(&ts->sched_timer), 1); tick_nohz_activate(ts, NOHZ_MODE_LOWRES); } -- cgit v1.2.3