On Thu, Aug 24, 2023 at 04:42:06PM +0800, Zqiang wrote:
> Currently, the maxcpu is set by traversing online CPUs, however, if
> the rcutorture.onoff_holdoff is set zero and onoff_interval is set
> non-zero, and the some CPUs with larger cpuid has been offline before
> setting maxcpu, for these CPUs, even if they are online again, also
> cannot be offload or deoffload.
>
> This commit therefore use for_each_possible_cpu() instead of
> for_each_online_cpu() in rcu_nocb_toggle().
>
> Signed-off-by: Zqiang <qiang.zhang1211@xxxxxxxxx>
> ---
> kernel/rcu/rcutorture.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
> index a58372bdf0c1..b75d0fe558ce 100644
> --- a/kernel/rcu/rcutorture.c
> +++ b/kernel/rcu/rcutorture.c
> @@ -2131,7 +2131,7 @@ static int rcu_nocb_toggle(void *arg)
> VERBOSE_TOROUT_STRING("rcu_nocb_toggle task started");
> while (!rcu_inkernel_boot_has_ended())
> schedule_timeout_interruptible(HZ / 10);
> - for_each_online_cpu(cpu)
> + for_each_possible_cpu(cpu)
Last I checked, bad things could happen if the code attempted to
nocb_toggle a CPU that had not yet come online. Has that changed?
Thanx, Paul
> maxcpu = cpu;
> WARN_ON(maxcpu < 0);
> if (toggle_interval > ULONG_MAX)
> --
> 2.17.1
>
