On Tue, Sep 12, 2023 at 08:56:47PM -0400, Liam R. Howlett wrote:
> diff --git a/init/main.c b/init/main.c
> index ad920fac325c..f74772acf612 100644
> --- a/init/main.c
> +++ b/init/main.c
> @@ -696,7 +696,7 @@ noinline void __ref __noreturn rest_init(void)
> */
> rcu_read_lock();
> tsk = find_task_by_pid_ns(pid, &init_pid_ns);
> - tsk->flags |= PF_NO_SETAFFINITY;
> + tsk->flags |= PF_NO_SETAFFINITY | PF_IDLE;
> set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id()));
> rcu_read_unlock();
>
Hmm, isn't that pid-1 you're setting PF_IDLE on?
The task becoming idle is 'current' at this point, see the
cpu_startup_entry() call below.
Would not something like so be the right thing?
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 2299a5cfbfb9..802551e0009b 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -9269,7 +9269,7 @@ void __init init_idle(struct task_struct *idle, int cpu)
* PF_KTHREAD should already be set at this point; regardless, make it
* look like a proper per-CPU kthread.
*/
- idle->flags |= PF_IDLE | PF_KTHREAD | PF_NO_SETAFFINITY;
+ idle->flags |= PF_KTHREAD | PF_NO_SETAFFINITY;
kthread_set_per_cpu(idle, cpu);
#ifdef CONFIG_SMP
diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c
index 342f58a329f5..5007b25c5bc6 100644
--- a/kernel/sched/idle.c
+++ b/kernel/sched/idle.c
@@ -373,6 +373,7 @@ EXPORT_SYMBOL_GPL(play_idle_precise);
void cpu_startup_entry(enum cpuhp_state state)
{
+ current->flags |= PF_IDLE;
arch_cpu_idle_prepare();
cpuhp_online_idle(state);
while (1)
