Re: [PATCH 1/2] powerpc: Use cpumask_next_wrap instead

From: Yury Norov

Date: Sat Mar 28 2026 - 16:44:47 EST


On Fri, Mar 27, 2026 at 12:01:28PM +0530, Shrikanth Hegde wrote:
> cpu = cpumask_next(cpu, mask)
> if (cpu >= nr_cpu_ids)
> cpu = cpumask_first(mask)
>
> Above block is identical to:
> cpu = cpumask_next_wrap(cpu, mask)
>
> Replace it, No change in functionality or performance.
> Slightly simpler code.
>
> Signed-off-by: Shrikanth Hegde <sshegde@xxxxxxxxxxxxx>
> ---
> arch/powerpc/kernel/irq.c | 5 +----
> arch/powerpc/mm/book3s64/hash_utils.c | 4 +---
> arch/powerpc/sysdev/xive/common.c | 5 +----
> 3 files changed, 3 insertions(+), 11 deletions(-)
>
> diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
> index a0e8b998c9b5..f69de08ad347 100644
> --- a/arch/powerpc/kernel/irq.c
> +++ b/arch/powerpc/kernel/irq.c
> @@ -370,10 +370,7 @@ int irq_choose_cpu(const struct cpumask *mask)
> do_round_robin:
> raw_spin_lock_irqsave(&irq_rover_lock, flags);
>
> - irq_rover = cpumask_next(irq_rover, cpu_online_mask);
> - if (irq_rover >= nr_cpu_ids)
> - irq_rover = cpumask_first(cpu_online_mask);
> -
> + irq_rover = cpumask_next_wrap(irq_rover, cpu_online_mask);
> cpuid = irq_rover;
>
> raw_spin_unlock_irqrestore(&irq_rover_lock, flags);
> diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c
> index 9dc5889d6ecb..e4fcf929cb33 100644
> --- a/arch/powerpc/mm/book3s64/hash_utils.c
> +++ b/arch/powerpc/mm/book3s64/hash_utils.c
> @@ -1299,9 +1299,7 @@ static void stress_hpt_timer_fn(struct timer_list *timer)
> if (!firmware_has_feature(FW_FEATURE_LPAR))
> tlbiel_all();
>
> - next_cpu = cpumask_next(raw_smp_processor_id(), cpu_online_mask);
> - if (next_cpu >= nr_cpu_ids)
> - next_cpu = cpumask_first(cpu_online_mask);
> + next_cpu = cpumask_next_wrap(raw_smp_processor_id(), cpu_online_mask);
> stress_hpt_timer.expires = jiffies + msecs_to_jiffies(10);
> add_timer_on(&stress_hpt_timer, next_cpu);
> }
> diff --git a/arch/powerpc/sysdev/xive/common.c b/arch/powerpc/sysdev/xive/common.c
> index e1a4f8a97393..b6446abe29a6 100644
> --- a/arch/powerpc/sysdev/xive/common.c
> +++ b/arch/powerpc/sysdev/xive/common.c
> @@ -577,10 +577,7 @@ static int xive_find_target_in_mask(const struct cpumask *mask,
> */
> if (cpu_online(cpu) && xive_try_pick_target(cpu))
> return cpu;
> - cpu = cpumask_next(cpu, mask);
> - /* Wrap around */
> - if (cpu >= nr_cpu_ids)
> - cpu = cpumask_first(mask);
> + cpu = cpumask_next_wrap(cpu, mask);

Again, for all except this:

Reviewed-by: Yury Norov <yury.norov@xxxxxxxxx>


Can you move my series for xive_find_target_in_mask() together with
your patches?

> } while (cpu != first);
>
> return -1;
> --
> 2.47.3