Commit-ID: dcdedb24159be3487e3dbbe1faa79ae7d00c92ac Gitweb: https://git.kernel.org/tip/dcdedb24159be3487e3dbbe1faa79ae7d00c92ac Author: Frederic Weisbecker <frede...@kernel.org> AuthorDate: Wed, 21 Feb 2018 05:17:28 +0100 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Wed, 21 Feb 2018 09:49:09 +0100
sched/nohz: Remove the 1 Hz tick code Now that the 1Hz tick is offloaded to workqueues, we can safely remove the residual code that used to handle it locally. Signed-off-by: Frederic Weisbecker <frede...@kernel.org> Reviewed-by: Thomas Gleixner <t...@linutronix.de> Acked-by: Peter Zijlstra <pet...@infradead.org> Cc: Chris Metcalf <cmetc...@mellanox.com> Cc: Christoph Lameter <c...@linux.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Luiz Capitulino <lcapitul...@redhat.com> Cc: Mike Galbraith <efa...@gmx.de> Cc: Paul E. McKenney <paul...@linux.vnet.ibm.com> Cc: Rik van Riel <r...@redhat.com> Cc: Wanpeng Li <kernel...@gmail.com> Link: http://lkml.kernel.org/r/1519186649-3242-7-git-send-email-frede...@kernel.org Signed-off-by: Ingo Molnar <mi...@kernel.org> --- include/linux/sched/nohz.h | 4 ---- kernel/sched/core.c | 29 ----------------------------- kernel/sched/idle_task.c | 1 - kernel/sched/sched.h | 11 +---------- kernel/time/tick-sched.c | 6 ------ 5 files changed, 1 insertion(+), 50 deletions(-) diff --git a/include/linux/sched/nohz.h b/include/linux/sched/nohz.h index 3d3a97d..0942172 100644 --- a/include/linux/sched/nohz.h +++ b/include/linux/sched/nohz.h @@ -37,8 +37,4 @@ extern void wake_up_nohz_cpu(int cpu); static inline void wake_up_nohz_cpu(int cpu) { } #endif -#ifdef CONFIG_NO_HZ_FULL -extern u64 scheduler_tick_max_deferment(void); -#endif - #endif /* _LINUX_SCHED_NOHZ_H */ diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 5dfef45..8fff4f1 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3096,35 +3096,9 @@ void scheduler_tick(void) rq->idle_balance = idle_cpu(cpu); trigger_load_balance(rq); #endif - rq_last_tick_reset(rq); } #ifdef CONFIG_NO_HZ_FULL -/** - * scheduler_tick_max_deferment - * - * Keep at least one tick per second when a single - * active task is running because the scheduler doesn't - * yet completely support full dynticks environment. - * - * This makes sure that uptime, CFS vruntime, load - * balancing, etc... continue to move forward, even - * with a very low granularity. - * - * Return: Maximum deferment in nanoseconds. - */ -u64 scheduler_tick_max_deferment(void) -{ - struct rq *rq = this_rq(); - unsigned long next, now = READ_ONCE(jiffies); - - next = rq->last_sched_tick + HZ; - - if (time_before_eq(next, now)) - return 0; - - return jiffies_to_nsecs(next - now); -} struct tick_work { int cpu; @@ -6116,9 +6090,6 @@ void __init sched_init(void) rq->last_load_update_tick = jiffies; rq->nohz_flags = 0; #endif -#ifdef CONFIG_NO_HZ_FULL - rq->last_sched_tick = 0; -#endif #endif /* CONFIG_SMP */ hrtick_rq_init(rq); atomic_set(&rq->nr_iowait, 0); diff --git a/kernel/sched/idle_task.c b/kernel/sched/idle_task.c index e1b46e0..48b8a83 100644 --- a/kernel/sched/idle_task.c +++ b/kernel/sched/idle_task.c @@ -48,7 +48,6 @@ dequeue_task_idle(struct rq *rq, struct task_struct *p, int flags) static void put_prev_task_idle(struct rq *rq, struct task_struct *prev) { - rq_last_tick_reset(rq); } /* diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index c1c7c78..dc6c8b5 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -727,9 +727,7 @@ struct rq { #endif /* CONFIG_SMP */ unsigned long nohz_flags; #endif /* CONFIG_NO_HZ_COMMON */ -#ifdef CONFIG_NO_HZ_FULL - unsigned long last_sched_tick; -#endif + /* capture load from *all* tasks on this cpu: */ struct load_weight load; unsigned long nr_load_updates; @@ -1626,13 +1624,6 @@ static inline void sub_nr_running(struct rq *rq, unsigned count) sched_update_tick_dependency(rq); } -static inline void rq_last_tick_reset(struct rq *rq) -{ -#ifdef CONFIG_NO_HZ_FULL - rq->last_sched_tick = jiffies; -#endif -} - extern void update_rq_clock(struct rq *rq); extern void activate_task(struct rq *rq, struct task_struct *p, int flags); diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index d479b21..f2fa2e9 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -748,12 +748,6 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts, delta = KTIME_MAX; } -#ifdef CONFIG_NO_HZ_FULL - /* Limit the tick delta to the maximum scheduler deferment */ - if (!ts->inidle) - delta = min(delta, scheduler_tick_max_deferment()); -#endif - /* Calculate the next expiry time */ if (delta < (KTIME_MAX - basemono)) expires = basemono + delta;
