On 2024-04-24 04:55, Dawei Li wrote:
> In general it's preferable to avoid placing cpumasks on the stack, as
> for large values of NR_CPUS these can consume significant amounts of
> stack space and make stack overflows more likely.
>
> Use cpumask_subset() and cpumask_first_and() to avoid the need for a
> temporary cpumask on the stack.
>
> Reviewed-by: Sam Ravnborg <sam@xxxxxxxxxxxx>
> Signed-off-by: Dawei Li <dawei.li@xxxxxxxxxxxx>
> ---
> arch/sparc/kernel/leon_kernel.c | 7 +++----
> 1 file changed, 3 insertions(+), 4 deletions(-)
>
> diff --git a/arch/sparc/kernel/leon_kernel.c b/arch/sparc/kernel/leon_kernel.c
> index 4c61da491fee..a43cf794bb1e 100644
> --- a/arch/sparc/kernel/leon_kernel.c
> +++ b/arch/sparc/kernel/leon_kernel.c
> @@ -106,13 +106,12 @@ unsigned long leon_get_irqmask(unsigned int irq)
> #ifdef CONFIG_SMP
> static int irq_choose_cpu(const struct cpumask *affinity)
> {
> - cpumask_t mask;
> + unsigned int cpu = cpumask_first_and(affinity, cpu_online_mask);
>
> - cpumask_and(&mask, cpu_online_mask, affinity);
> - if (cpumask_equal(&mask, cpu_online_mask) || cpumask_empty(&mask))
> + if (cpumask_subset(cpu_online_mask, affinity) || cpu >= nr_cpu_ids)
> return boot_cpu_id;
> else
> - return cpumask_first(&mask);
> + return cpu;
> }
> #else
> #define irq_choose_cpu(affinity) boot_cpu_id
Reviewed-by: Andreas Larsson <andreas@xxxxxxxxxxx>
Tested-by: Andreas Larsson <andreas@xxxxxxxxxxx>
Picking this up to my for-next.
Thanks,
Andreas
