From 5d7696053592d0d28b59006bca62a36ea81449cd Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 18 Jul 2011 13:59:17 +0200 Subject: [PATCH 220/323] softirq: Disable softirq stacks for RT Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.10/older/patches-5.10.215-rt107.tar.xz Disable extra stacks for softirqs. We want to preempt softirqs and having them on special IRQ-stack does not make this easier. Signed-off-by: Thomas Gleixner --- arch/powerpc/kernel/irq.c | 2 ++ arch/powerpc/kernel/misc_32.S | 2 ++ arch/powerpc/kernel/misc_64.S | 2 ++ arch/sh/kernel/irq.c | 2 ++ arch/sparc/kernel/irq_64.c | 2 ++ arch/x86/kernel/irq_32.c | 2 ++ arch/x86/kernel/irq_64.c | 2 ++ include/linux/interrupt.h | 2 +- 8 files changed, 15 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c index e8a548447dd68..5ad4f27cba104 100644 --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -753,10 +753,12 @@ void *mcheckirq_ctx[NR_CPUS] __read_mostly; void *softirq_ctx[NR_CPUS] __read_mostly; void *hardirq_ctx[NR_CPUS] __read_mostly; +#ifndef CONFIG_PREEMPT_RT void do_softirq_own_stack(void) { call_do_softirq(softirq_ctx[smp_processor_id()]); } +#endif irq_hw_number_t virq_to_hw(unsigned int virq) { diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S index 717e658b90fd8..08ee95ad6593a 100644 --- a/arch/powerpc/kernel/misc_32.S +++ b/arch/powerpc/kernel/misc_32.S @@ -31,6 +31,7 @@ * We store the saved ksp_limit in the unused part * of the STACK_FRAME_OVERHEAD */ +#ifndef CONFIG_PREEMPT_RT _GLOBAL(call_do_softirq) mflr r0 stw r0,4(r1) @@ -46,6 +47,7 @@ _GLOBAL(call_do_softirq) stw r10,THREAD+KSP_LIMIT(r2) mtlr r0 blr +#endif /* * void call_do_irq(struct pt_regs *regs, void *sp); diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S index 070465825c210..a6b33f7b32646 100644 --- a/arch/powerpc/kernel/misc_64.S +++ b/arch/powerpc/kernel/misc_64.S @@ -27,6 +27,7 @@ .text +#ifndef CONFIG_PREEMPT_RT _GLOBAL(call_do_softirq) mflr r0 std r0,16(r1) @@ -37,6 +38,7 @@ _GLOBAL(call_do_softirq) ld r0,16(r1) mtlr r0 blr +#endif _GLOBAL(call_do_irq) mflr r0 diff --git a/arch/sh/kernel/irq.c b/arch/sh/kernel/irq.c index ab5f790b0cd27..5db7af565decc 100644 --- a/arch/sh/kernel/irq.c +++ b/arch/sh/kernel/irq.c @@ -148,6 +148,7 @@ void irq_ctx_exit(int cpu) hardirq_ctx[cpu] = NULL; } +#ifndef CONFIG_PREEMPT_RT void do_softirq_own_stack(void) { struct thread_info *curctx; @@ -175,6 +176,7 @@ void do_softirq_own_stack(void) "r5", "r6", "r7", "r8", "r9", "r15", "t", "pr" ); } +#endif #else static inline void handle_one_irq(unsigned int irq) { diff --git a/arch/sparc/kernel/irq_64.c b/arch/sparc/kernel/irq_64.c index 3ec9f1402aad3..eb21682abfcb1 100644 --- a/arch/sparc/kernel/irq_64.c +++ b/arch/sparc/kernel/irq_64.c @@ -854,6 +854,7 @@ void __irq_entry handler_irq(int pil, struct pt_regs *regs) set_irq_regs(old_regs); } +#ifndef CONFIG_PREEMPT_RT void do_softirq_own_stack(void) { void *orig_sp, *sp = softirq_stack[smp_processor_id()]; @@ -868,6 +869,7 @@ void do_softirq_own_stack(void) __asm__ __volatile__("mov %0, %%sp" : : "r" (orig_sp)); } +#endif #ifdef CONFIG_HOTPLUG_CPU void fixup_irqs(void) diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c index 0b79efc87be52..93c6b88b382a0 100644 --- a/arch/x86/kernel/irq_32.c +++ b/arch/x86/kernel/irq_32.c @@ -131,6 +131,7 @@ int irq_init_percpu_irqstack(unsigned int cpu) return 0; } +#ifndef CONFIG_PREEMPT_RT void do_softirq_own_stack(void) { struct irq_stack *irqstk; @@ -147,6 +148,7 @@ void do_softirq_own_stack(void) call_on_stack(__do_softirq, isp); } +#endif void __handle_irq(struct irq_desc *desc, struct pt_regs *regs) { diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c index 440eed558558d..7cfc4e6b7c94a 100644 --- a/arch/x86/kernel/irq_64.c +++ b/arch/x86/kernel/irq_64.c @@ -72,7 +72,9 @@ int irq_init_percpu_irqstack(unsigned int cpu) return map_irq_stack(cpu); } +#ifndef CONFIG_PREEMPT_RT void do_softirq_own_stack(void) { run_on_irqstack_cond(__do_softirq, NULL); } +#endif diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index a1c64d969532d..7f185482ea221 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -564,7 +564,7 @@ struct softirq_action asmlinkage void do_softirq(void); asmlinkage void __do_softirq(void); -#ifdef __ARCH_HAS_DO_SOFTIRQ +#if defined(__ARCH_HAS_DO_SOFTIRQ) && !defined(CONFIG_PREEMPT_RT) void do_softirq_own_stack(void); #else static inline void do_softirq_own_stack(void) -- 2.44.0