From: Thomas Gleixner Date: Mon, 18 Jul 2011 13:59:17 +0200 Subject: [PATCH 120/353] softirq: Disable softirq stacks for RT Origin: https://git.kernel.org/cgit/linux/kernel/git/rt/linux-stable-rt.git/commit?id=fd9bd08b1b2f9c99314b78b5e9e402a877996522 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/entry/entry_64.S | 2 ++ arch/x86/kernel/irq_32.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 d37704ebccdb..b45a9849b687 100644 --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -766,6 +766,7 @@ void irq_ctx_init(void) } } +#ifndef CONFIG_PREEMPT_RT_FULL void do_softirq_own_stack(void) { struct thread_info *curtp, *irqtp; @@ -783,6 +784,7 @@ void do_softirq_own_stack(void) if (irqtp->flags) set_bits(irqtp->flags, &curtp->flags); } +#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 695b24a2d954..032ada21b7bd 100644 --- a/arch/powerpc/kernel/misc_32.S +++ b/arch/powerpc/kernel/misc_32.S @@ -42,6 +42,7 @@ * We store the saved ksp_limit in the unused part * of the STACK_FRAME_OVERHEAD */ +#ifndef CONFIG_PREEMPT_RT_FULL _GLOBAL(call_do_softirq) mflr r0 stw r0,4(r1) @@ -58,6 +59,7 @@ _GLOBAL(call_do_softirq) stw r10,THREAD+KSP_LIMIT(r2) mtlr r0 blr +#endif /* * void call_do_irq(struct pt_regs *regs, struct thread_info *irqtp); diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S index facc02964ab3..8b1774186c68 100644 --- a/arch/powerpc/kernel/misc_64.S +++ b/arch/powerpc/kernel/misc_64.S @@ -32,6 +32,7 @@ .text +#ifndef CONFIG_PREEMPT_RT_FULL _GLOBAL(call_do_softirq) mflr r0 std r0,16(r1) @@ -42,6 +43,7 @@ _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 5717c7cbdd97..66dd399b2007 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_FULL 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 713670e6d13d..5dfc715343f9 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_FULL 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/entry/entry_64.S b/arch/x86/entry/entry_64.S index ef693d3689aa..891b7b2f5d3b 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -1087,6 +1087,7 @@ EXPORT_SYMBOL(native_load_gs_index) jmp 2b .previous +#ifndef CONFIG_PREEMPT_RT_FULL /* Call softirq on interrupt stack. Interrupts are off. */ ENTRY(do_softirq_own_stack) pushq %rbp @@ -1097,6 +1098,7 @@ ENTRY(do_softirq_own_stack) leaveq ret ENDPROC(do_softirq_own_stack) +#endif #ifdef CONFIG_XEN idtentry hypervisor_callback xen_do_hypervisor_callback has_error_code=0 diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c index 95600a99ae93..9192d76085ba 100644 --- a/arch/x86/kernel/irq_32.c +++ b/arch/x86/kernel/irq_32.c @@ -130,6 +130,7 @@ void irq_ctx_init(int cpu) cpu, per_cpu(hardirq_stack, cpu), per_cpu(softirq_stack, cpu)); } +#ifndef CONFIG_PREEMPT_RT_FULL void do_softirq_own_stack(void) { struct irq_stack *irqstk; @@ -146,6 +147,7 @@ void do_softirq_own_stack(void) call_on_stack(__do_softirq, isp); } +#endif bool handle_irq(struct irq_desc *desc, struct pt_regs *regs) { diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 35fa335c475b..eec4bec454b5 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -500,7 +500,7 @@ 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_FULL) void do_softirq_own_stack(void); #else static inline void do_softirq_own_stack(void)