From a92057e14beb233e8c891f4de075f2a468c71f15 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Sat, 3 Mar 2018 15:44:39 +0100 Subject: [PATCH] sched/idle: Merge kernel/sched/idle.c and kernel/sched/idle_task.c Merge these two small .c modules as they implement two aspects of idle task handling. Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar --- kernel/sched/Makefile | 5 +- kernel/sched/idle.c | 123 ++++++++++++++++++++++++++++++++++++++++++++++- kernel/sched/idle_task.c | 117 -------------------------------------------- 3 files changed, 125 insertions(+), 120 deletions(-) delete mode 100644 kernel/sched/idle_task.c diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile index e2f9d4f..d9a02b3 100644 --- a/kernel/sched/Makefile +++ b/kernel/sched/Makefile @@ -17,8 +17,9 @@ CFLAGS_core.o := $(PROFILING) -fno-omit-frame-pointer endif obj-y += core.o loadavg.o clock.o cputime.o -obj-y += idle_task.o fair.o rt.o deadline.o -obj-y += wait.o wait_bit.o swait.o completion.o idle.o +obj-y += idle.o fair.o rt.o deadline.o +obj-y += wait.o wait_bit.o swait.o completion.o + obj-$(CONFIG_SMP) += cpupri.o cpudeadline.o topology.o stop_task.o obj-$(CONFIG_SCHED_AUTOGROUP) += autogroup.o obj-$(CONFIG_SCHEDSTATS) += stats.o diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c index 2760e03..2975f19 100644 --- a/kernel/sched/idle.c +++ b/kernel/sched/idle.c @@ -1,5 +1,9 @@ /* - * Generic entry points for the idle threads + * Generic entry points for the idle threads and + * implementation of the idle task scheduling class. + * + * (NOTE: these are not related to SCHED_IDLE batch scheduled + * tasks which are handled in sched/fair.c ) */ #include "sched.h" @@ -33,6 +37,7 @@ void cpu_idle_poll_ctrl(bool enable) static int __init cpu_idle_poll_setup(char *__unused) { cpu_idle_force_poll = 1; + return 1; } __setup("nohlt", cpu_idle_poll_setup); @@ -40,6 +45,7 @@ __setup("nohlt", cpu_idle_poll_setup); static int __init cpu_idle_nopoll_setup(char *__unused) { cpu_idle_force_poll = 0; + return 1; } __setup("hlt", cpu_idle_nopoll_setup); @@ -51,12 +57,14 @@ static noinline int __cpuidle cpu_idle_poll(void) trace_cpu_idle_rcuidle(0, smp_processor_id()); local_irq_enable(); stop_critical_timings(); + while (!tif_need_resched() && (cpu_idle_force_poll || tick_check_broadcast_expired())) cpu_relax(); start_critical_timings(); trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id()); rcu_idle_exit(); + return 1; } @@ -337,3 +345,116 @@ void cpu_startup_entry(enum cpuhp_state state) while (1) do_idle(); } + +/* + * idle-task scheduling class. + */ + +#ifdef CONFIG_SMP +static int +select_task_rq_idle(struct task_struct *p, int cpu, int sd_flag, int flags) +{ + return task_cpu(p); /* IDLE tasks as never migrated */ +} +#endif + +/* + * Idle tasks are unconditionally rescheduled: + */ +static void check_preempt_curr_idle(struct rq *rq, struct task_struct *p, int flags) +{ + resched_curr(rq); +} + +static struct task_struct * +pick_next_task_idle(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) +{ + put_prev_task(rq, prev); + update_idle_core(rq); + schedstat_inc(rq->sched_goidle); + + return rq->idle; +} + +/* + * It is not legal to sleep in the idle task - print a warning + * message if some code attempts to do it: + */ +static void +dequeue_task_idle(struct rq *rq, struct task_struct *p, int flags) +{ + raw_spin_unlock_irq(&rq->lock); + printk(KERN_ERR "bad: scheduling from the idle thread!\n"); + dump_stack(); + raw_spin_lock_irq(&rq->lock); +} + +static void put_prev_task_idle(struct rq *rq, struct task_struct *prev) +{ +} + +/* + * scheduler tick hitting a task of our scheduling class. + * + * NOTE: This function can be called remotely by the tick offload that + * goes along full dynticks. Therefore no local assumption can be made + * and everything must be accessed through the @rq and @curr passed in + * parameters. + */ +static void task_tick_idle(struct rq *rq, struct task_struct *curr, int queued) +{ +} + +static void set_curr_task_idle(struct rq *rq) +{ +} + +static void switched_to_idle(struct rq *rq, struct task_struct *p) +{ + BUG(); +} + +static void +prio_changed_idle(struct rq *rq, struct task_struct *p, int oldprio) +{ + BUG(); +} + +static unsigned int get_rr_interval_idle(struct rq *rq, struct task_struct *task) +{ + return 0; +} + +static void update_curr_idle(struct rq *rq) +{ +} + +/* + * Simple, special scheduling class for the per-CPU idle tasks: + */ +const struct sched_class idle_sched_class = { + /* .next is NULL */ + /* no enqueue/yield_task for idle tasks */ + + /* dequeue is not valid, we print a debug message there: */ + .dequeue_task = dequeue_task_idle, + + .check_preempt_curr = check_preempt_curr_idle, + + .pick_next_task = pick_next_task_idle, + .put_prev_task = put_prev_task_idle, + +#ifdef CONFIG_SMP + .select_task_rq = select_task_rq_idle, + .set_cpus_allowed = set_cpus_allowed_common, +#endif + + .set_curr_task = set_curr_task_idle, + .task_tick = task_tick_idle, + + .get_rr_interval = get_rr_interval_idle, + + .prio_changed = prio_changed_idle, + .switched_to = switched_to_idle, + .update_curr = update_curr_idle, +}; diff --git a/kernel/sched/idle_task.c b/kernel/sched/idle_task.c deleted file mode 100644 index 488222a..0000000 --- a/kernel/sched/idle_task.c +++ /dev/null @@ -1,117 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * idle-task scheduling class. - * - * (NOTE: these are not related to SCHED_IDLE batch scheduling tasks which are - * handled in sched/fair.c) - */ -#include "sched.h" - -#ifdef CONFIG_SMP -static int -select_task_rq_idle(struct task_struct *p, int cpu, int sd_flag, int flags) -{ - return task_cpu(p); /* IDLE tasks as never migrated */ -} -#endif - -/* - * Idle tasks are unconditionally rescheduled: - */ -static void check_preempt_curr_idle(struct rq *rq, struct task_struct *p, int flags) -{ - resched_curr(rq); -} - -static struct task_struct * -pick_next_task_idle(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) -{ - put_prev_task(rq, prev); - update_idle_core(rq); - schedstat_inc(rq->sched_goidle); - - return rq->idle; -} - -/* - * It is not legal to sleep in the idle task - print a warning - * message if some code attempts to do it: - */ -static void -dequeue_task_idle(struct rq *rq, struct task_struct *p, int flags) -{ - raw_spin_unlock_irq(&rq->lock); - printk(KERN_ERR "bad: scheduling from the idle thread!\n"); - dump_stack(); - raw_spin_lock_irq(&rq->lock); -} - -static void put_prev_task_idle(struct rq *rq, struct task_struct *prev) -{ -} - -/* - * scheduler tick hitting a task of our scheduling class. - * - * NOTE: This function can be called remotely by the tick offload that - * goes along full dynticks. Therefore no local assumption can be made - * and everything must be accessed through the @rq and @curr passed in - * parameters. - */ -static void task_tick_idle(struct rq *rq, struct task_struct *curr, int queued) -{ -} - -static void set_curr_task_idle(struct rq *rq) -{ -} - -static void switched_to_idle(struct rq *rq, struct task_struct *p) -{ - BUG(); -} - -static void -prio_changed_idle(struct rq *rq, struct task_struct *p, int oldprio) -{ - BUG(); -} - -static unsigned int get_rr_interval_idle(struct rq *rq, struct task_struct *task) -{ - return 0; -} - -static void update_curr_idle(struct rq *rq) -{ -} - -/* - * Simple, special scheduling class for the per-CPU idle tasks: - */ -const struct sched_class idle_sched_class = { - /* .next is NULL */ - /* no enqueue/yield_task for idle tasks */ - - /* dequeue is not valid, we print a debug message there: */ - .dequeue_task = dequeue_task_idle, - - .check_preempt_curr = check_preempt_curr_idle, - - .pick_next_task = pick_next_task_idle, - .put_prev_task = put_prev_task_idle, - -#ifdef CONFIG_SMP - .select_task_rq = select_task_rq_idle, - .set_cpus_allowed = set_cpus_allowed_common, -#endif - - .set_curr_task = set_curr_task_idle, - .task_tick = task_tick_idle, - - .get_rr_interval = get_rr_interval_idle, - - .prio_changed = prio_changed_idle, - .switched_to = switched_to_idle, - .update_curr = update_curr_idle, -}; -- 2.7.4