Re: [PATCH] arm64: use SOFTIRQ_ON_OWN_STACK for enabling softirq stack

[Ryo Takakura <ryotkkr98@gmail.com>]

Hi!

On Tue, 4 Nov 2025 13:58:13 +0000, Will Deacon wrote:
>On Mon, Oct 13, 2025 at 01:35:08AM +0000, Ryo Takakura wrote:
>> For those architectures with HAVE_SOFTIRQ_ON_OWN_STACK use
>> their dedicated softirq stack when !PREEMPT_RT. This condition
>> is ensured by SOFTIRQ_ON_OWN_STACK.
>> 
>> Let arm64 use SOFTIRQ_ON_OWN_STACK as well to select its
>> usage of the stack.
>> 
>> Signed-off-by: Ryo Takakura <ryotkkr98@gmail.com>
>> ---
>>  arch/arm64/kernel/irq.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>> 
>> diff --git a/arch/arm64/kernel/irq.c b/arch/arm64/kernel/irq.c
>> index c0065a1d77cf..15dedb385b9e 100644
>> --- a/arch/arm64/kernel/irq.c
>> +++ b/arch/arm64/kernel/irq.c
>> @@ -62,7 +62,7 @@ static void __init init_irq_stacks(void)
>>  	}
>>  }
>>  
>> -#ifndef CONFIG_PREEMPT_RT
>> +#ifdef CONFIG_SOFTIRQ_ON_OWN_STACK
>>  static void ____do_softirq(struct pt_regs *regs)
>>  {
>>  	__do_softirq();
>
>Acked-by: Will Deacon <will@kernel.org>

Thanks Sebastian and Will for checking!
I'll shortly send v2 with the tags.

Sincerely,
Ryo Takakura

>Will