[v2] arm64: use SOFTIRQ_ON_OWN_STACK for enabling softirq stack

[PATCH v2] arm64: use SOFTIRQ_ON_OWN_STACK for enabling softirq stack

Posted by Ryo Takakura 1 month, 2 weeks 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>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Will Deacon <will@kernel.org>
---

Changes since v1:
[1] https://lore.kernel.org/linux-rt-devel/20251013013508.74677-1-ryotkkr98@gmail.com/

- Add <Reviewed-by> by Sebastian.
- Add <Acked-by> by Will.

---
 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 c0065a1d7..15dedb385 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 v2] arm64: use SOFTIRQ_ON_OWN_STACK for enabling softirq stack

Posted by Catalin Marinas 1 month, 1 week ago

On Wed, 05 Nov 2025 16:42:59 +0900, 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.
> 
> [...]

Applied to arm64 (for-next/misc), thanks!

[1/1] arm64: use SOFTIRQ_ON_OWN_STACK for enabling softirq stack
      https://git.kernel.org/arm64/c/d3b570eba7bf

-- 
Catalin