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sched/core: Make select_task_rq() take the pointer to wake_flags instead of value

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This will be used to allow select_task_rq() to indicate whether
->select_task_rq() was called by modifying *wake_flags.

This makes try_to_wake_up() call all functions that take wake_flags with
WF_TTWU set. Previously, only select_task_rq() was. Using the same flags is
more consistent, and, as the flag is only tested by ->select_task_rq()
implementations, it doesn't cause any behavior differences.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David Vernet <void@manifault.com>
This commit is contained in:
Tejun Heo 2024-09-27 13:46:11 -10:00
parent ec010333ce
commit b62933eee4
1 changed files with 8 additions and 5 deletions
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13
kernel/sched/core.c
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@ -3518,12 +3518,12 @@ out:
* The caller (fork, wakeup) owns p->pi_lock, ->cpus_ptr is stable.
*/
static inline
int select_task_rq(struct task_struct *p, int cpu, int wake_flags)
int select_task_rq(struct task_struct *p, int cpu, int *wake_flags)
{
lockdep_assert_held(&p->pi_lock);
if (p->nr_cpus_allowed > 1 && !is_migration_disabled(p))
cpu = p->sched_class->select_task_rq(p, cpu, wake_flags);
cpu = p->sched_class->select_task_rq(p, cpu, *wake_flags);
else
cpu = cpumask_any(p->cpus_ptr);
@ -4120,6 +4120,8 @@ int try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
guard(preempt)();
int cpu, success = 0;
wake_flags |= WF_TTWU;
if (p == current) {
/*
* We're waking current, this means 'p->on_rq' and 'task_cpu(p)
@ -4252,7 +4254,7 @@ int try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
*/
smp_cond_load_acquire(&p->on_cpu, !VAL);
cpu = select_task_rq(p, p->wake_cpu, wake_flags | WF_TTWU);
cpu = select_task_rq(p, p->wake_cpu, &wake_flags);
if (task_cpu(p) != cpu) {
if (p->in_iowait) {
delayacct_blkio_end(p);
@ -4793,6 +4795,7 @@ void wake_up_new_task(struct task_struct *p)
{
struct rq_flags rf;
struct rq *rq;
int wake_flags = WF_FORK;
raw_spin_lock_irqsave(&p->pi_lock, rf.flags);
WRITE_ONCE(p->__state, TASK_RUNNING);
@ -4807,7 +4810,7 @@ void wake_up_new_task(struct task_struct *p)
*/
p->recent_used_cpu = task_cpu(p);
rseq_migrate(p);
__set_task_cpu(p, select_task_rq(p, task_cpu(p), WF_FORK));
__set_task_cpu(p, select_task_rq(p, task_cpu(p), &wake_flags));
#endif
rq = __task_rq_lock(p, &rf);
update_rq_clock(rq);
@ -4815,7 +4818,7 @@ void wake_up_new_task(struct task_struct *p)
activate_task(rq, p, ENQUEUE_NOCLOCK | ENQUEUE_INITIAL);
trace_sched_wakeup_new(p);
wakeup_preempt(rq, p, WF_FORK);
wakeup_preempt(rq, p, wake_flags);
#ifdef CONFIG_SMP
if (p->sched_class->task_woken) {
/*