>
> On Sun, Dec 14, 2025 at 10:49:04AM +0800, Zqiang wrote:
>
> >
> > The cblist_init_generic() is executed during the CPU early boot
> > phase due to commit:30ef09635b9e ("rcu-tasks: Initialize callback
> > lists at rcu_init() time"), at this time, only one boot CPU is
> > online. this commit therefore use WRITE_ONCE() to replace the
> > smp_store_release() to assigning rtp->percpu_enqueue_lim in the
> > cblist_init_generic().
> >
> > Signed-off-by: Zqiang <[email protected]>
> >
> Good eyes, thank you!
>
> But in that case, we are running on a single CPU with interrupts disables,
> so do we even need WRITE_ONCE()?
I missed the interrupts disabled, It seems like there are no need use
WRITE_ONCE()
and include above, I will update and resend.
Thanks
Zqiang
>
> Thanx, Paul
>
> >
> > ---
> > kernel/rcu/tasks.h | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h
> > index 76f952196a29..f763f60d5e50 100644
> > --- a/kernel/rcu/tasks.h
> > +++ b/kernel/rcu/tasks.h
> > @@ -292,7 +292,7 @@ static void cblist_init_generic(struct rcu_tasks *rtp)
> > shift++;
> > WRITE_ONCE(rtp->percpu_enqueue_shift, shift);
> > WRITE_ONCE(rtp->percpu_dequeue_lim, lim);
> > - smp_store_release(&rtp->percpu_enqueue_lim, lim);
> > + WRITE_ONCE(rtp->percpu_enqueue_lim, lim);
> >
> > pr_info("%s: Setting shift to %d and lim to %d rcu_task_cb_adjust=%d
> > rcu_task_cpu_ids=%d.\n",
> > rtp->name, data_race(rtp->percpu_enqueue_shift),
> > data_race(rtp->percpu_enqueue_lim),
> > --
> > 2.48.1
> >
>
