Contributors: 12
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Peter Zijlstra |
340 |
65.64% |
7 |
35.00% |
| Mike Galbraith |
121 |
23.36% |
1 |
5.00% |
| Thomas Gleixner |
15 |
2.90% |
1 |
5.00% |
| Frédéric Weisbecker |
13 |
2.51% |
2 |
10.00% |
| Paul Turner |
12 |
2.32% |
1 |
5.00% |
| Kirill V Tkhai |
9 |
1.74% |
2 |
10.00% |
| Matt Fleming |
3 |
0.58% |
1 |
5.00% |
| Ingo Molnar |
1 |
0.19% |
1 |
5.00% |
| Dario Faggioli |
1 |
0.19% |
1 |
5.00% |
| Tejun Heo |
1 |
0.19% |
1 |
5.00% |
| Greg Kroah-Hartman |
1 |
0.19% |
1 |
5.00% |
| Borislav Petkov |
1 |
0.19% |
1 |
5.00% |
| Total |
518 |
|
20 |
|
// SPDX-License-Identifier: GPL-2.0
/*
* stop-task scheduling class.
*
* The stop task is the highest priority task in the system, it preempts
* everything and will be preempted by nothing.
*
* See kernel/stop_machine.c
*/
#include "sched.h"
#ifdef CONFIG_SMP
static int
select_task_rq_stop(struct task_struct *p, int cpu, int sd_flag, int flags)
{
return task_cpu(p); /* stop tasks as never migrate */
}
#endif /* CONFIG_SMP */
static void
check_preempt_curr_stop(struct rq *rq, struct task_struct *p, int flags)
{
/* we're never preempted */
}
static struct task_struct *
pick_next_task_stop(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
{
struct task_struct *stop = rq->stop;
if (!stop || !task_on_rq_queued(stop))
return NULL;
put_prev_task(rq, prev);
stop->se.exec_start = rq_clock_task(rq);
return stop;
}
static void
enqueue_task_stop(struct rq *rq, struct task_struct *p, int flags)
{
add_nr_running(rq, 1);
}
static void
dequeue_task_stop(struct rq *rq, struct task_struct *p, int flags)
{
sub_nr_running(rq, 1);
}
static void yield_task_stop(struct rq *rq)
{
BUG(); /* the stop task should never yield, its pointless. */
}
static void put_prev_task_stop(struct rq *rq, struct task_struct *prev)
{
struct task_struct *curr = rq->curr;
u64 delta_exec;
delta_exec = rq_clock_task(rq) - curr->se.exec_start;
if (unlikely((s64)delta_exec < 0))
delta_exec = 0;
schedstat_set(curr->se.statistics.exec_max,
max(curr->se.statistics.exec_max, delta_exec));
curr->se.sum_exec_runtime += delta_exec;
account_group_exec_runtime(curr, delta_exec);
curr->se.exec_start = rq_clock_task(rq);
cgroup_account_cputime(curr, delta_exec);
}
/*
* 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_stop(struct rq *rq, struct task_struct *curr, int queued)
{
}
static void set_curr_task_stop(struct rq *rq)
{
struct task_struct *stop = rq->stop;
stop->se.exec_start = rq_clock_task(rq);
}
static void switched_to_stop(struct rq *rq, struct task_struct *p)
{
BUG(); /* its impossible to change to this class */
}
static void
prio_changed_stop(struct rq *rq, struct task_struct *p, int oldprio)
{
BUG(); /* how!?, what priority? */
}
static unsigned int
get_rr_interval_stop(struct rq *rq, struct task_struct *task)
{
return 0;
}
static void update_curr_stop(struct rq *rq)
{
}
/*
* Simple, special scheduling class for the per-CPU stop tasks:
*/
const struct sched_class stop_sched_class = {
.next = &dl_sched_class,
.enqueue_task = enqueue_task_stop,
.dequeue_task = dequeue_task_stop,
.yield_task = yield_task_stop,
.check_preempt_curr = check_preempt_curr_stop,
.pick_next_task = pick_next_task_stop,
.put_prev_task = put_prev_task_stop,
#ifdef CONFIG_SMP
.select_task_rq = select_task_rq_stop,
.set_cpus_allowed = set_cpus_allowed_common,
#endif
.set_curr_task = set_curr_task_stop,
.task_tick = task_tick_stop,
.get_rr_interval = get_rr_interval_stop,
.prio_changed = prio_changed_stop,
.switched_to = switched_to_stop,
.update_curr = update_curr_stop,
};