Re: [PATCH 4/6] genirq: optimize irq_do_set_affinity()

[Jinjie Ruan]

On 2024/5/14 6:01, Yury Norov wrote:
> If mask == desc->irq_common_data.affinity, copying one to another is
> useless, and we can just skip it.
> 
> Signed-off-by: Yury Norov <yury.norov@xxxxxxxxx>
> ---
>  kernel/irq/manage.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
> index bf9ae8a8686f..ad9ed9fdf919 100644
> --- a/kernel/irq/manage.c
> +++ b/kernel/irq/manage.c
> @@ -285,7 +285,8 @@ int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
>  	switch (ret) {
>  	case IRQ_SET_MASK_OK:
>  	case IRQ_SET_MASK_OK_DONE:
> -		cpumask_copy(desc->irq_common_data.affinity, mask);
> +		if (desc->irq_common_data.affinity != mask)
> +			cpumask_copy(desc->irq_common_data.affinity, mask);

It seems that mask is a pointer, shouldn't use "cpumask_equal"？

>  		fallthrough;
>  	case IRQ_SET_MASK_OK_NOCOPY:
>  		irq_validate_effective_affinity(data);