diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2021-09-24 18:12:45 +0200 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2021-09-27 12:28:32 +0200 |
| commit | 441e90369344d229c0f04024ea5d4d51f06b137d (patch) | |
| tree | a66979eafb0fc79d3a9d393835e22aeb9ab553b9 | |
| parent | b70e13885cf63b6f99cbd9a1dbb6beaa2622bf68 (diff) | |
x86/softirq: Disable softirq stacks on PREEMPT_RT
PREEMPT_RT preempts softirqs and the current implementation avoids
do_softirq_own_stack() and only uses __do_softirq().
Disable the unused softirqs stacks on PREEMPT_RT to safe some memory and
ensure that do_softirq_own_stack() is not used which is not expected.
[ bigeasy: commit description. ]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210924161245.2357247-1-bigeasy@linutronix.de
| -rw-r--r-- | arch/x86/include/asm/irq_stack.h | 3 | ||||
| -rw-r--r-- | arch/x86/kernel/irq_32.c | 2 |
2 files changed, 5 insertions, 0 deletions
diff --git a/arch/x86/include/asm/irq_stack.h b/arch/x86/include/asm/irq_stack.h index 562854c60808..ea0c5ab31da4 100644 --- a/arch/x86/include/asm/irq_stack.h +++ b/arch/x86/include/asm/irq_stack.h @@ -185,6 +185,7 @@ IRQ_CONSTRAINTS, regs, vector); \ } +#ifndef CONFIG_PREEMPT_RT #define ASM_CALL_SOFTIRQ \ "call %P[__func] \n" @@ -201,6 +202,8 @@ __this_cpu_write(hardirq_stack_inuse, false); \ } +#endif + #else /* CONFIG_X86_64 */ /* System vector handlers always run on the stack they interrupted. */ #define run_sysvec_on_irqstack_cond(func, regs) \ diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c index 044902d5a3c4..e5dd6da78713 100644 --- a/arch/x86/kernel/irq_32.c +++ b/arch/x86/kernel/irq_32.c @@ -132,6 +132,7 @@ int irq_init_percpu_irqstack(unsigned int cpu) return 0; } +#ifndef CONFIG_PREEMPT_RT void do_softirq_own_stack(void) { struct irq_stack *irqstk; @@ -148,6 +149,7 @@ void do_softirq_own_stack(void) call_on_stack(__do_softirq, isp); } +#endif void __handle_irq(struct irq_desc *desc, struct pt_regs *regs) { |