[v1] arm64: use SOFTIRQ_ON_OWN_STACK for enabling softirq stack

[PATCH] arm64: use SOFTIRQ_ON_OWN_STACK for enabling softirq stack

Posted by Ryo Takakura 2 months, 1 week ago

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();
-- 
2.34.1

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

Posted by Will Deacon 1 month, 2 weeks ago

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>

Will

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

Posted by Ryo Takakura 1 month, 2 weeks ago

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

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

Posted by Sebastian Andrzej Siewior 2 months, 1 week ago

On 2025-10-13 01:35:08 [+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>

Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

Sebastian