On Mon, Jul 13, 2026 at 06:31:26PM +0800, Zqiang wrote:
> Currently, the comments: "We can't create the thread unless interrupts
> are enabled." from 'commit 4929c913bda5 ("rcu: Make call_rcu_tasks()
> tolerate first call with irqs disabled")', now the kthread creation
> has been move to core_initcall() time from 'commit c63eb17ff06d
> ("rcu: Create call_rcu_tasks() kthread at boot time")', and use the
> irq_work does deferred wakeup. this commit therefore update comments
> in call_rcu_tasks_generic().
>
> Signed-off-by: Zqiang <[email protected]>
Queued and pushed both, thank you! I adjusted the comment and commit log,
so please double-check them in case I messed something up.
Thanx, Paul
> ---
> kernel/rcu/tasks.h | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h
> index a2ca79d1dd6a..089a0d5a5cc9 100644
> --- a/kernel/rcu/tasks.h
> +++ b/kernel/rcu/tasks.h
> @@ -395,7 +395,11 @@ static void call_rcu_tasks_generic(struct rcu_head *rhp,
> rcu_callback_t func,
> raw_spin_unlock_irqrestore(&rtp->cbs_gbl_lock, flags);
> }
> rcu_read_unlock();
> - /* We can't create the thread unless interrupts are enabled. */
> + // We can't create the kthread with interrupts disabled,
> + // or a spinlock might be held, the kthread creation has
> + // been move to core_initcall() time.
> + // at the same time, use the irq_work does deferred wakeup
> + // to avoid potential lockdep splat.
> if (needwake && READ_ONCE(rtp->kthread_ptr))
> irq_work_queue(&rtpcp->rtp_irq_work);
> }
> --
> 2.17.1
>
