Remove the CONFIG_PREEMPT_RT symbol from the ifdef around do_softirq_own_stack() and move it to Kconfig instead. Enable softirq stacks based on SOFTIRQ_ON_OWN_STACK which depends on HAVE_SOFTIRQ_ON_OWN_STACK and its default value is set to !PREEMPT_RT. This ensures that softirq stacks are not used on PREEMPT_RT and avoids a 'select' statement on an option which has a 'depends' statement. Link: https://lore.kernel.org/YvN5E%2FPrHfUhggr7@xxxxxxxxxxxxx Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> --- Arnd, could you please route it via your tree? v1…v2: - Use "def_bool HAVE_SOFTIRQ_ON_OWN_STACK && !PREEMPT_RT" arch/Kconfig | 3 +++ arch/arm/kernel/irq.c | 2 +- arch/parisc/kernel/irq.c | 2 +- arch/powerpc/kernel/irq.c | 4 ++-- arch/s390/include/asm/softirq_stack.h | 2 +- arch/sh/kernel/irq.c | 2 +- arch/sparc/kernel/irq_64.c | 2 +- arch/x86/include/asm/irq_stack.h | 2 +- arch/x86/kernel/irq_32.c | 2 +- include/asm-generic/softirq_stack.h | 2 +- 10 files changed, 13 insertions(+), 10 deletions(-) --- a/arch/Kconfig +++ b/arch/Kconfig @@ -923,6 +923,9 @@ config HAVE_SOFTIRQ_ON_OWN_STACK Architecture provides a function to run __do_softirq() on a separate stack. +config SOFTIRQ_ON_OWN_STACK + def_bool HAVE_SOFTIRQ_ON_OWN_STACK && !PREEMPT_RT + config ALTERNATE_USER_ADDRESS_SPACE bool help --- a/arch/arm/kernel/irq.c +++ b/arch/arm/kernel/irq.c @@ -70,7 +70,7 @@ static void __init init_irq_stacks(void) } } -#ifndef CONFIG_PREEMPT_RT +#ifdef CONFIG_SOFTIRQ_ON_OWN_STACK static void ____do_softirq(void *arg) { __do_softirq(); --- a/arch/parisc/kernel/irq.c +++ b/arch/parisc/kernel/irq.c @@ -480,7 +480,7 @@ static void execute_on_irq_stack(void *f *irq_stack_in_use = 1; } -#ifndef CONFIG_PREEMPT_RT +#ifdef CONFIG_SOFTIRQ_ON_OWN_STACK void do_softirq_own_stack(void) { execute_on_irq_stack(__do_softirq, 0); --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -199,7 +199,7 @@ static inline void check_stack_overflow( } } -#ifndef CONFIG_PREEMPT_RT +#ifdef CONFIG_SOFTIRQ_ON_OWN_STACK static __always_inline void call_do_softirq(const void *sp) { /* Temporarily switch r1 to sp, call __do_softirq() then restore r1. */ @@ -335,7 +335,7 @@ void *mcheckirq_ctx[NR_CPUS] __read_most void *softirq_ctx[NR_CPUS] __read_mostly; void *hardirq_ctx[NR_CPUS] __read_mostly; -#ifndef CONFIG_PREEMPT_RT +#ifdef CONFIG_SOFTIRQ_ON_OWN_STACK void do_softirq_own_stack(void) { call_do_softirq(softirq_ctx[smp_processor_id()]); --- a/arch/s390/include/asm/softirq_stack.h +++ b/arch/s390/include/asm/softirq_stack.h @@ -5,7 +5,7 @@ #include <asm/lowcore.h> #include <asm/stacktrace.h> -#ifndef CONFIG_PREEMPT_RT +#ifdef CONFIG_SOFTIRQ_ON_OWN_STACK static inline void do_softirq_own_stack(void) { call_on_stack(0, S390_lowcore.async_stack, void, __do_softirq); --- a/arch/sh/kernel/irq.c +++ b/arch/sh/kernel/irq.c @@ -149,7 +149,7 @@ void irq_ctx_exit(int cpu) hardirq_ctx[cpu] = NULL; } -#ifndef CONFIG_PREEMPT_RT +#ifdef CONFIG_SOFTIRQ_ON_OWN_STACK void do_softirq_own_stack(void) { struct thread_info *curctx; --- a/arch/sparc/kernel/irq_64.c +++ b/arch/sparc/kernel/irq_64.c @@ -855,7 +855,7 @@ void __irq_entry handler_irq(int pil, st set_irq_regs(old_regs); } -#ifndef CONFIG_PREEMPT_RT +#ifdef CONFIG_SOFTIRQ_ON_OWN_STACK void do_softirq_own_stack(void) { void *orig_sp, *sp = softirq_stack[smp_processor_id()]; --- a/arch/x86/include/asm/irq_stack.h +++ b/arch/x86/include/asm/irq_stack.h @@ -203,7 +203,7 @@ IRQ_CONSTRAINTS, regs, vector); \ } -#ifndef CONFIG_PREEMPT_RT +#ifdef CONFIG_SOFTIRQ_ON_OWN_STACK /* * Macro to invoke __do_softirq on the irq stack. This is only called from * task context when bottom halves are about to be reenabled and soft --- a/arch/x86/kernel/irq_32.c +++ b/arch/x86/kernel/irq_32.c @@ -132,7 +132,7 @@ int irq_init_percpu_irqstack(unsigned in return 0; } -#ifndef CONFIG_PREEMPT_RT +#ifdef CONFIG_SOFTIRQ_ON_OWN_STACK void do_softirq_own_stack(void) { struct irq_stack *irqstk; --- a/include/asm-generic/softirq_stack.h +++ b/include/asm-generic/softirq_stack.h @@ -2,7 +2,7 @@ #ifndef __ASM_GENERIC_SOFTIRQ_STACK_H #define __ASM_GENERIC_SOFTIRQ_STACK_H -#if defined(CONFIG_HAVE_SOFTIRQ_ON_OWN_STACK) && !defined(CONFIG_PREEMPT_RT) +#ifdef CONFIG_SOFTIRQ_ON_OWN_STACK void do_softirq_own_stack(void); #else static inline void do_softirq_own_stack(void)