* Christophe Leroy christophe.leroy@csgroup.eu [230912 13:09]:
Le 12/09/2023 à 17:44, Liam R. Howlett a écrit :
diff --git a/init/main.c b/init/main.c index dbe1fe76be34..fd4739918a94 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;
Is it really what you want to do ?
PF_NO_SETAFFINITY is 0x04000000 and PF_IDLE is 0x00000002 so
PF_NO_SETAFFINITY & PF_IDLE is 0
Didn't you mean to do PF_NO_SETAFFINITY | PF_IDLE ?
Yes, certainly.
Regardless, with either change I don't get the warning anymore.
I don't have it fully tested but we avoid getting the call_rcu() setting the TIF_... flag by avoiding the task having PF_IDLE set in the flags. I'm not entirely sure if I have added the set/clear in the best locations either.
The largest concern I have is that this could potentially change arch or platfrom code if anything depends on this being idle.
set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id())); rcu_read_unlock(); @@ -943,6 +943,7 @@ void start_kernel(void) * time - but meanwhile we still have a functioning scheduler. */ sched_init();
- current->flags &= ~PF_IDLE;
if (WARN(!irqs_disabled(), "Interrupts were enabled *very* early, fixing it\n"))